STUDIES IN SMALL-POX AND VACCINATION STUDIES IN SMALL-POX AND VACCINATION WILLIAM HANNA, M.A., M.D., D.P.H. Assistant Medical Officer of Health for the Port of Liverpool ; Visiting Physician to the Port Isolation Hospital. NEW YORK: WILLIAM WOOD AND COMPANY. MDCCCCXIII. o 00 ^ N in " r^ ■r, o ^ « t^ ^ u^ > • "6 IC OH " n-1 vO lO > o ^ O 5 a> t/1 * o^ ZS CT> 00 4 y. '^. > • 13 S, A H " - O -r 'O •B t^ fo ro ■ -c 3S " Ov -»• •g ^ > 00 ZS tn P-: o\ o> fO m « i •T3 tn « lO CO V Z S o 3 S o M m ■= >ri ii ^ s ^ rn Z IS ^ dS "1 « 00 o 00 ? « (/I y, t^ Z S li r^ ->. w c 3 dS m o\ t^ o> r^ ° 3! S iK o " D > zS ZS Z « ZS O ' ^ 0.^ i S 1 5 3 U CS13 p an <■ m d o o o Hi ^ z L) ^ *" Q iz; < ^^ W n, OQ H *-^ T tq f^ < w o 8 ~o vO 55 ^ d 3 a >o ^ r^ 1 > o^ 0-- a^ in o. ^^ jO o S zS -^o s? o o o a 3 , 3 . „ o o • -,o ^, -o ^o g| O o o o Q o » 1 ^^ o? ;2 t- >o Si o5 O c o i o •d o^ .? ^ o? > o 00 Oi 00 o? S5 5 S! rr, r 3 fl Z n in o p, i > t^ =f VO ' lO t! ^o - o o? 5-° = y N 00 w T ■" > o fO -fl" > r- ^ r* ox S M "J^ O ro ^ m o M 1 'O z « 1 00 T °t Ov 1^ s ^ ^o ~~p «i > (^ fO Z n 1 •^ ^V, P >a - o -.o o J, V. ,o .,o > o> 0^ ^ s 1 > •? ^ ft b b ■a o Si rt Z^ Z iS > " ^ ^ -o o CO I a a to b CO Y, ■ « O 1) P % 2:S 1 > " ' -M toi3 'S '^ "g «; o U !> 6 g •^1 t; n! P 15 and imperfectly vaccinated, a case-mortality of from 3 to g per cent, whilst it reached over 40 per cent in the un- vaccinated, and in various other places it was just as high. The small-pox of the last decennium has been of a fairly mild type. The question of age distribution in the population attacked, and the country of origin of the disease, may have an important influence in determining the virulence of an epidemic. On the Chart A (pages 16, 17) and in the accompany- ing tables, the cases have been arranged into suitable age periods, so as to show clearly the value of vaccination on the mortality in passing from infancy to adult and old age. An examination of the deaths recorded amongst the vaccinated under each age-group reveals the interesting fact that no death occurred until the 20-30 year group is reached, and the case-mortality for this group is only 0"9 per cent. It will be observed, however, that the percentage case-mortality amongst the vaccinated steadily rises from this point onwards in life, but never exceeds 10 per cent. On contrasting these figures with those amongst the unvaccinated, we observe a striking difference. Under 2 years of age the deaths are 58 per cent of the cases attacked, for 2-5 years 30'6 per cent, and the figure then falls until 10-15 years, when it is 3-2 per cent. This decrease may be attributed to the gradual development of the natural resistance and recuperative power of youth enabling the patient to recover from the disease ; this may be compared with what is observed in other infectious diseases. From adolescence onwards the mortality in the unvaccinated gradually increases, until it reaches 50 per cent at the periods from 40 years and upwards. This high ratio of deaths to attacks amongst D £ < a « 1 > 1 ^■i ' J 3^1 ' "■■ , 5 S O ( ootnoiftbinoinou ^ o in o in o g ' ; ; ! ; "ff 1 r^^^t I ■ ^ ^^^^H °' ~T - ^.. i j- --1 1 ^J 1 "4 i i ^ ^ i.-: -. - i ■ S ^ 3L 1 I t -1^ ■ - 6 = "M j ■; 1 4 ; - hIh-i i m r.:_ . i ' :m 1- -1 r ■ ^ = -^-^- ■ 1 ': ^ ■ ^. ^ 3:. - ' r^ ■ " 1 ■ ^^ !r^ y ^ ^ ^ m fc. M .. --; -=*-- 1^ l« 6 o in 6, m ^ m M m m H m = J i^ p ^ -^ 17 2 t O > u .-ti H o rt a i-i '"^ < u ho .o tfi o o c! cd o (U w ti "5 »H cd en cd ni > &| Pk (U <-< c^ 18 the unvaccinated, especially at the early and late periods of life, compares with what is well known of this disease in pre- vaccination days, viz., that the severity and mortality lay heaviest on infants and young children under ten years of age. The large excess of births and rapid accumulation of susceptible persons in the growing manufacturing towns afforded ample material for an epidemic to feed upon; therefore the number of adults and old people who had escaped the disease in pre-vaccination days was few. At the present time, when an epidemic spreads over the country, in addition to the unvaccinated children, the disease also attacks those adults who have never been vaccinated in their youth, and in addition, the power of recovering from small-pox decreases as age advances. The Influence of Vaccination on the Eruption, and ON the Severity of the Disease. The amount of eruption on the body of a patient affected with small-pox always gives one an opportunity to form an opinion of the severity and probable - fatality of the case. The eruption may be divided into five categories, and commencing with the very mildest, these are as follows : modified discrete, discrete, profuse discrete, semi-confluent, and confluent. For purposes of easy examination they have been grouped with the descriptive terms as follows : — A. — Modified discrete and discrete, representing the mild types of the disease. B. — Profuse discrete and semi-confluent ; a moderate type of severity. PLATE I A IMILD AND MODIFIED CASE OF SMALL-POX Patient well vaccinated in infancy, the scar area approximating one square inch. Age twentv-five years. Note the mild character of the eruption, which is, as usual, chiefly confined as regards distribution to the face and extremities. The usual freedom of the triangle of the neck from eruption is to be noted. PLATE J 11 WELL-MARKED CASE OF SMALL-POX OF SEVERE CHARACTER IN A MAN WHO NEVER BEEN VACCINATED UNTIL AFTER INFECTION WITH SMALL-POX Patient unvaccinated in infancy. Vaccinated for first time seven days before onset. Age twenty-two years. Note the severity of tlie case, tlie size of the pustules, and distribution of the eruption, more marked on face and extremities than on body. The vaccination has been successful, and without doubt saved the man's life; he recovered completely. Photo taken on ninth day of eruption. 19 C. — Confluejtt or very severe ; to this last category have been added those in which death occurred. There are therefore three types of severity, viz., A mild, B moderate, and C severe {see Plates I, II, and III). Let us examine the eruption and severity at different ages, as it occurs in the natural disease, i.e., in the imvaccinated {see Chart A, page i6). An examination of the column under 0-2 years of age shows that over 58 per cent of the cases at this age period are found with the fatal kind of small-pox, 31 per cent with the medium type, and only 10 per cent with the mild form of the disease ; the same is also the case for the period 2-5 years, showing the marked incidence of the severe kind on unvaccinated childhood. Contrast in Chart A the severity of the disease and mortality under 10 years of age in the unvaccinated with the similar columns in the vaccinated. The middle period of life has a lower percentage of severe cases ; this may be explained by the higher resistance of the body and power of recovery, which gradually increase up to 30-35 years of age ; this natural resistance is well shown in the unvaccinated in Chart A. The number of cases of moderate severity continues high in the unvaccinated throughout life, but as- age advances, the very severe type again appears. The dark-shaded portion in the chart indicates the mortality limit amongst the severe cases ; and it will be observed that from 10 years onwards to 40 years many severe and confluent cases recover. Compare this with the severe cases followed by death in children under 10 years and in old people, that is, at the extremes of life. 20 I. Influence on the Extent of the Eruption. The effect of vaccination is to reinforce the natural immunity of the body. When it does not prevent the onset of the disease, it may either influence the extent of the eruption or modify the character of the individual papules. Let us consider first the influence of vaccination on the extent of the eruption. On contrasting in Tables I and // and Chart A, the primarily vaccinated cases under the different age-groups, a distinct series of facts will become apparent. In the first place, there are no cases recorded under 2 years*, and only seven cases under 5 years ; the latter, moreover, were exceedingly mild in character and characterized by very sparse eruptions, a few papules only appearing in isolated parts of the body. Again, only three cases of moderate severity appear under 10 years of age, and of the severe type no cases are recorded under 20 years. When the columns of vaccin- ated persons in Table II are contrasted, it will be seen that the percentages of persons with the different forms of the disease are graduated : the highest percentages in each age group are found to have the disease in a mild form, the next highest in moderate form, and so on; the most severe cases show the lowest percentage and only appear after 25-30 years of age, and the deaths occurring in this period are comparatively low. On the total cases of all ages amongst the vaccinated, the percentages are 727 of mild type, 237 moderate, and only 3 '6 of a severe character. The protection afforded by vaccination against attacks of the disease is therefore well seen in this investigation, where no cases of small-pox in the vaccinated are to be found under 2 years of age* {see pages 13, 14, 16), that is, * See footnote, page 31. 21 in the years immediately following upon the process of vaccination. II. Influence in Modifying the Character of the Specific Eruption. The eruption of unmodified small-pox usually passes through a well-recognized series of changes. The first appearance of the eruption takes place approximately three days after the onset of symptoms, as red spots about the size of a pin's head, first seen chiefly on the forehead and wrists. They cannot be felt as distinct spots above the skin, and disappear on pressure. Shortly after, they swell into raised pink papules, fairly hard and easily perceptible to the touch ; they grow in size and can frequently be recognized as " shotty," but this depends on their position in the skin and the tension of the contents due to effused fluid. After a day or so, when they have become, in typical cases, rounded and defined, vesiculation develops, and at the beginning of the third day the papules have become vesicular. These vesicles are loculated, and if pricked, the clear contents will escape in small amount. The loculation is due to trabeculae running through the interior which divide the pock into several compartments. These vesicles gradually become opaque or grey in colour, and the contents become pustular ; this happens about the sixth day of the eruption, and by the eighth, ninth, or tenth day they begin to dry up, with the formation of crusts. This is the typical course in all cases except those of a severe or hsemorrhagic character. In cases modified by vaccination, various interesting changes may be demonstrated in the character of the eruption. The following modifications in the eruption due to 3 22 vaccination have been noted in the series under examina- tion. 1. The papules have been numerically few in number and limited to isolated parts of the body. They have, however, gone through the typical course of evolution. 2. The rash has been profuse, but the lesions were superficially placed ; the vesicles or pustules were frequently small or irregular in size, and owing to their superficial position were unilocular, like vesicles in chicken-pox ; in some cases they evolved quickly, and suppurated early and imperfectly. 3. The papules, owing to wart-like masses of granula- tion tissue formed at the base, appeared as raised fleshy elevations. 4. A concurrent vaccination might cause rapid inspissation of the pustules, the crusts dropping off early. In' the accompanying Plate IV, the first type is well illustrated ; the rash is very sparse, the papules passing through the various typical stages as in natural small- pox, attaining full size. The type described under No. 2 is well shown in Plate V, where the rash is very profuse, but the individual lesions are much smaller than those occurring in natural small-pox, the pustules varying in size from a pin's head to a pea within a small area ; they are superficially placed in the skin, and the eruption has passed through to suppuration quickly and imperfectly. In this respect it is well known that the rapidity of evolution of a papule varies with its size and the depth of its situation in the skin, and the photos show the effect of the vaccination in bringing about this condition. Another type illustrated, Plate VI, shows a modified eruption which is known under the name of " wart-pocks." These pocks are chiefly found on the face, and consist of PLATE IV A MILD AND MODIFIED CASE OF SMALL-POX INFECTED. SIX DAYS BEFORE BIRTH. FROM ITS MOTHER The child was born in hospital and successfully vaccinated on the same day Age fifteen days. Note the few and scattered papules on this infant, the modihed character is due to the successful vaccination which was done six days before onset of disease. Photo taken on the seventh day of eruption. PLATE V MODIFIED CASE OF SMALL-POX, SHOWING IN THIS CASE A NEVOID CHARACTER OF A CONCURRENT VACCINATION Patient vaccinated in infancy. Re-vaccinated oii the day of appearance of eruption. A^e twenty-six years. ' In tins case of small pox the rash >s Profuse but extremely modified, the papules vary much in size are superficially placed rnatur- iuK rapidly and irregularly. (A) Superficially placed and rapidly maturing papules. Photo taken on ninth day of rash. PLATE VI A WELL-MARKED CASE OF SMALL-POX, SHOWING CONDITION OF "WART POCK ■' This type of case, altliough somewhat repulsive in appearance, is nevertheless fairlv mild m its character, and permanent disfigurement or pitting rarely follows. PLATE VI I SEVERE CASE OF SMALL-POX, NOT VACCINATED BEFORE INFECTION. Patient unvaccinated in infancy. Vaccinated on the day following the appear- ance of the rasli. .^ge thirty-four years. Ttie case sliows the effect of a con- current vaccination on the course of the disease, a rapid pustulation and drying up of the rash. (A) Atypical vaccination scars with aborted vesicle and yellow crust. The clear areas around each scar are not vesicles, but white or pinkish areas left by the retraction of the scab. Photo taken on the thirteenth day of rash. 23 papules raised by the formation of wart-like masses of granulation tissue; the papules have a fleshy base, and frequently the suppurative process is shortened, the pocks being surmounted by a yellow pustule about the size of a pin's head, which soon dries up, pitting is rare. [ Frequently, a vaccination when performed after the date of infection, or even after the onset, has the effect of hastening the maturation and desiccation of the pustules.y For example, Plate VII shows a patient, un vaccinated in infancy, who developed small-pox with a sudden and violent onset and profuse rash. Vaccination was performed on the day following the appearance of the rash, but in spite of this it was thought the course of the disease would prove to be severe. Suppuration set in about the usual time. When the pustular stage ought to have reached its height, however, and the patient would have been in a most critical condition, the temperature fell, the pustules at once began to inspissate and form crusts, and then rapidly fell off. The patient was free from crusts in an incredibly short time. This rapid passage through the pustular and desiccation stages was undoubtedly due to the vaccination. Ricketts regards vaccination as having a double effect on the course of the disease : one effect is an influ- ence on the extent of the rash, or the numerical severity ; the other is in the direction of modifying the eruption. As age advances he regards these two faculties as waning together, but " the protective influence against numicrical severity goes quicker, and the faculty to cause an eruption to be modified is retained for years after the other is wholly lost." These points are well illustrated in the series of photographs which accompany this paper. 24 De-vaccination. The length of the period of protection can be fairly well gauged by an examination of the appended Tables. The period will vary a good deal for each individual, but from the figures given, the highest resistance lasts only a short time. After a few years those who become susceptible develop the disease only in a mild form, and further on in years greater severity manifests itself in the type of the disease, but no cases of severe and fatal small- pox appear in this series of cases until over 20 years of age. It is evident, then, that following a primary vaccination in infancy, the period of greatest protection in childhood probably does not cover more than three to five years, and after this, the absolutely preventive efficiency of vaccination rapidly diminishes, and cases of small-pox begin to appear amongst the vaccinated. The power to modify the disease, however, still continues to remain considerable until adolescence, and even into later life, as will be seen by comparing the severity and the percentage case-mortality in different age-groups of vaccinated and unvaccinated cases. ( The rapid loss of vaccinal immunity following on primary vaccination in infancy is probably to be explained x by the rapid changes going on during growth in childhood. y' The experience of those who have done much vaccination in adolescents or adults shows that the protection afforded to adults by re-vaccination lasts much longer than the same operation in children. It is well known that this restored protection again diminishes, but much more slowlyw An instructive example of this gradual loss of pro- tection was shown in six members of a family (a mother 25 and five children) admitted to hospital suffering from small-pox. The disease attacked them all in varying degrees of severity. They all showed evidence of having been vaccinated in infancy : each of the children had only one vaccination scar, of | square inch in area ; the mother had three vaccination scars, each of the same size. Case Age Number of Scars. Scar-area Character of Disease Remarks I 4 years I § sq. inch Modified discrete, very mild Papules very few, not over 7-8, and not vesicular. 27.. I ditto ditto ditto. 3 9 ,. I ditto ditto Papules few, more numerous than in cases I and 2, not vesicular. 4 12 ,, I ditto Modified discrete, mild Papules very numer- ous, became vesicular but soon dried up. 5 15 I ditto ditto ditto. 6 37 3 I J sq. inch Discrete Eruption more marked than in the children, and passed through the charac- teristic stages. This series shows the gradual loss of the modifying power in the vaccination as age advances, and it is interest- ing as shown in the same family, the vaccination scar-area being the same in each case except in the mother, whose scar-areas were much larger, and therefore her protection showed a proportionally larger degree of modifying power. Where age has advanced sufficiently to ehminate the 4 26 previous vaccinal protection, it will be found that the disease reverts to its original type, as seen in the unvaccinated. In many cases, however, the immunity conferred in infancy may persist in some degree until late in life, especially in its power to modify the disease. This gradual loss of immunity is well shown in the vaccinated, in Chart A {page i6), where as age advances the mild cases become fewer in number, and later in life the severe types of the disease, with deaths, begin to appear. 27 PART 11. AN ANALYSIS OF 943 CASES OF SMALL-POX (WITH PRIMARY VACCINATION) IN RELATION TO SCAR-AREA AND SEVERITY OF DISEASE. The beneficial effects of vaccination are to be experienced especially in those cases where the process has been carried out in a thorough manner, and we may conclude that where vaccine lymph has been inserted in several places it is more effectual than when inserted in one place only, i.e., the larger the local manufactory of immunity or the greater the quantity of the specific material inserted, the greater the degree of the resulting protection. Accordingly, the amount of immunity may be reckoned by the superficial area of the scar. An analysis of the above-mentioned 943 cases of small-pox, which had been primarily vaccinated, was carried out to test the point. The scar-area was recorded for each vaccinated case of small-pox on admission to hospital, according to the method referred to in the circular letter of the Local Government Board of England, issued in 1902. The diagram (on page 28) represented the area of the scars in square inches, and was used to estimate it rapidly, and to record it. This method of recording superficial area is a much better one for estimating the relationship of immunity to mortality and severity, than that of counting the number of scars, as was done in the valuable series of Dr. Marson and others. 28 The scar-areas were arranged into age and severity groups; an average scar-area was also obtained for each age period ; this gi-ouping of scar-areas into severity and age groups has proved a most important one, and some "O 'O *o "O V J Scar-area Diagram of the Local Government Board. new facts have come to hght regarding tlie changes which scar-areas undergo. A glance at the figures in Table III will illustrate clearly the arrangement in relation to severity and age. The severity groups are the same as those used in the examination of the previous set of small-pox cases in Part I. 29 IT) ?> 00 i ''T ^ 00 A ui 4 00 1 I o ? 00 op I 0- V 1 I i_n o 2; 2 ^ o i o 2 r " 2; o 2; 1 o i!" Si 3 o 2; 1 o o 2; ■a : e n i • « o ■o : a C8 11 s •a a cs +-" c u 3 30 c •o s r> s i ;f i 9 % k f- ?. 00 I ? I ? i U-) o o •S ! < W K H H f^i O iz; O ?! < S X o o « Ph Uh J ^ 1-1 < a ^. < H ^ t/) ffi ?^ n H rn O « ;5 y > g < H O X O ^ ^ § H 00 < eo ,J ^ (I. O PL. o 0, < J w <; « K < W 1^ w o w o •< « w > < 3 1 1 i » i 9 r 11 g ? I ^ 2 i li lO 31 In the early years of life it is striking, as previously stated, to find that under two years of age no cases of small-pox are found amongst those who have had a primary vaccination in infancy,* from 2-5 years only very mild cases, and from 5-20 years no severe cases of small-pox, or deaths, have occurred. ■ In the remaining years of life, it is interesting to observe that in almost every age group the mildest types of the disease (modified discrete and discrete) are those with the largest average scar-area ; those with moderate or severe types of the disease (profuse and semi- confluent) have a slightly smaller scar-area, at least in mid-age periods ; and in those with the most severe types of small-pox, or where deaths have occurred, the scar-area is the smallest (see scar-area diagram, page 32). It would be well to note that it is a difficult matter to lay down a standard of severity for each group of cases, especially of the mildest types. The general impression created by the extent of the eruption being the only guide, cases on the border line are difficult to locate, and when the cases in any group are comparatively few, the more diffi- cult it is to attain absolute accuracy. It is clearly evident, however, that the scar-area of the vaccination bears an inverse relation to the character of the eruption and intensity of the disease. An ex- amination of Table IV, A, will show the average scar- area for all the cases at each age-period. It is striking to notice the gradual increase in this scar-area until 20-30 years, and following on this, a gradual decline in the size of this area as years advance. * I do not here include cases of small-pox in infants (see chart and photographs at the end) who have been vaccinated for the first time after infection with the disease, and have been in many cases bom in a small-pox hospital. These are included amongst "concurrent cases," which are dealt with in Part III. as a separate class. 32 Q Z < z o H < J D 3- o o a* Q J M J H < ^f' <^ Z CO ^H u fT, < O > c/: en O z < o < ^T- < z Di u < u fvl < < U t/) S < ttS o < ^ 5 / ; » J / f /■ § ^ / 1 • J r / / 1 1 ; r ^•. ; / / y / ' f^ 4 ' f y / / / ^ ^ f < * ■^^ . k ■^ 1 \ ■ \ s \ s \ ^ 5 \ \ \ L K \ 5 •^ \ V V \ > V s 1 CM \ "w ^ y V ) \ ^ '^ 5 *) ~ > c i o ' "? D ^ - u > -^ ■> \ »■ t^ ■> t^ J ^ - <: ' ^ Co t: 5 1 n) ? ?S vL m f^ 5 ^ t: ;§. ^ CJ - H U > > ^^iriiiiiiiiiiiiXiXXXXXXXiiiXX S o _o III 1 1 1 iX'XXiX'XXiX XXXi 1 QQ o ^■^XXXXX iXiiX'Xiiii'iii 'II Q U S « O In a cu en < g P < g u u < > X o Z o w < w en 5 o > < Q o> eath )eath 00 1 1 1 1 1 II 1 1 1 1 1 1 1 1 < ' 1 t^ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 o lllllllllllllllllllrillll<<<<" s ;C^ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 < 1 1 1 1 ;J 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 << 1 1 1 1 1 s 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 < 1 1 1 1 1 1 1 o" 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 < ; 1 1 1 1 1 1 1 1 M 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 > 1 1 1 1 1 1 1 1 1 o 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0> IIIJIIII !>>! 00 lllllllllllll>>>ll> g t^ 1 1 1 1 1 1 1 1 1 1 >>> 1 1 1 1 1 r |vO 1 J 1 1 1 1 1 1 >> 1 t 1 1 1 1 1 1 < 5 "^ 2 1 1 1 1 1 1 >> 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 > 1 1 1 1 I 1 1 1 1 1 1 1 1 « 1 1 1 1 > 1 1 1 1 1 1 1 1 1 1 1 1 1 1 N 1 >>> 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 H 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 2 o .9 > 1 1 1 1 1 1 1 1 1 t 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 6 Z iH « ro Tf irj'O t^oo CTi w W ^ '*• "^O t^co O^ 7- 1 ro en < Six or seven papules A few papules Thirty or forty papules Ten or twelve papules Few papules Few papules Only a few papules Few papules 00 Aorted papules Few papules < in « o s- H M > C/5 > 'X 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 . 1 . 1 1 1 1 1 1 r F 1 1 1 1 'Xii'XiiiiiXiiiiiii'iiXi.iXXXXiiiXXXXXi s XXXXXXX . iXX iXXXXX iXXXXXXXXXX iXXX . 1 1 iXXX X Q H o « en o H <: g o o <: > Pi IB (J s O w to <: w tn Q (I. O % « 1 '•' 1 '' 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 i 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 00 ' ' ' ' ' Ill 1 1 1 1 ' 1 1 1 1 1 <<<< H ' ' > I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 <<<< . 1 , 1 <<<< , J" 1 1 . 1 1 1 , 1 , , , , 1,1, <<<< , f 1 1 1 I 1 1 1 1 I 1 1 1 ' 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 r 1 1 1 1 1 1 1 1 r 1 1 1 1 ^ — I 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 1 1 < J 1 1 1 1 1 1 1 1 1 1 J 1 1 1 1 1 d O " 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 r 1 >> 1 1 t 1 1 1 1 1 1 1 1 1 1 1 , 1 1 1 1 M O OS < 1 <> I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 >> 1 I 1 1 1 1 1 1 J 1 1 1 1 1 1 i 1 r 1 1 5^ > 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 r 1 1 1 1 1 1 1 1 1 z I 1 > 1 1 1 1 1 1 1 1 J 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 B 00 1 1 1 1 1 1 1 1 1 ■ 1 1 1 1 1 1 1 1 1 >>>> 1 1 1 1 1 1 1 1 1 1 1 f 1 1 1 1 J 1 1 1 1 1 a 1 S t^ 1 1 1 1 1 1 1 1 1 1 1 1 1 >>>>>> 1 .. 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 r 1 1 ,, , < 1« < 5*" 1 1 1 1 >>>>>>>>> I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 , 1 , d 1 1 >> 1 1 1 1 1 1 1 1 1 1 > 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 3 ■i^ > ^ 1 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 J 1 1 1 1 1 1 1 1 1 > to > 1 1 1 1 1 1 1 1 1 1 r J 1 1 1 1 1 1 1 1 J 1 1 1 1 1 1 1 1 "3 N 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ' 1 1 1 1 1 1 1 1 1 J 1 1 1 r 1 I " 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ' 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 J T > J3 0.2 O rt^ 1 1 1 1 I 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 J 1 1 1 1 , d M N ro •* irj^O C^OO O O M n fO ^ in^C t-^CO Ov O m ^ ro -^ lOO t^OO OS O M N n^ ■^^ xTi^O C^OO 0« O M N ^ -^ ir^.l 39 The cases have been set out showing those vaccinated and re- vaccinated on different days : first, during the period of incubation, and second, after the onset of symptoms, and even until three days after the rash had appeared. It is unnecessary to say that vaccination efficiently per- formed in susceptible people before exposure to infection of small-pox will, almost without exception, prove successful, and will protect the individual from developing any symptoms or signs of the disease. Vaccination during Incubation. — On examining the charts it will be found that all the vaccinations and re- vaccinations have been successful if performed during the incubation period and even up to the day of onset of sym- ptoms. When the term "successful" is used, it must be understood that the phenomena at the site went through the typical and normal course of human vaccination. These phenomena may be shortly described as follows : a sUght inflammatory reaction may appear at the site, but nothing of moment occurs until the end of the third day, when firm, fiat, elevated papules appear at the site of the operation ; these become surrounded by a halo of hyper- aemia. Vesicles appear on the fifth or sixth day, and are especially marked at the periphery. These are filled with clear lymph, and the zone of hypersemia has increased, with acute swelling ; the vaccination is red and firm, and the axillary glands may be swollen. Cloudiness begins to appear in the vesicles on the eighth day, and subsequently they become opaque and yellow. The height of the vaccination is reached on the ninth or tenth day, and from this date there are signs of rapid desiccation. The changes most characteristic of vaccination are found during the third, fourth, fifth, and sixth days. The successful vaccinations and re-vaccinations 40 recorded in the charts were therefore more or less of the above-described characters, and they all showed the characteristic ring or vesicle situated on a papule and going on to suppuration and desiccation. {See Plates IX and X.) Vaccination after onset of the disease. — -The operations performed subsequently to the onset of symptoms were unsuccessful {see Plates XI, and XI I). The papule did not reach its typical character, the areola may not have developed and vesicles did not appear, or the vaccine pocks developed a nsevoid character or appeared stunted in development, and rapidly dried up. It must be granted, however, that in some of the cases the organisms introduced into the system may have had some modifying effect on the course of the disease, although no typical reaction occurred. This point will be referred to later. In other cases, and notably in those vaccinated late in the disease, no reaction appeared at the site, or simply a slight trau- matic reaction occurred. It will be well to mention at this point, that fallacious conclusions may be drawn from the appearance of the vaccination area under the following conditions. It is well known that an especially abundant eruption is not infrequently observed on parts of the body which, before the eruption appears, have been affected by mechanical or inflammatory irritation {see Plate XIII). Such areas of eruption are sharply marked off, and take on strikingly the form of the area of irritation, e.g., a patient who has been previously carrying heavy bags on his back will show a more profuse eruption on his shoulders, or the irritation in the front of the neck caused by a collar stud will cause a little crop of vesicles to appear at this point. Other examples might be mentioned, such as an eruption round the thigh where a garter has caused pressure. PLATE VIII MOTHER SUFFERING FROM SMALL-POX NURSING HER SUCCESSFULLY VACCINATED BABY. Mother aged twenty-five years. Vaccinated in infancy. Baby born in liospital and successfully vaccinated on the following day. No signs or symptoms of small-pox appeared in the child, which was nursed by the mother throughout her own illness in hospital, and discharged after six weeks, (A) Infant's successful vaccination. Photo taken on the ninth day of the vaccination. PLATE IX A VERY MILD AND MODIFIED CASE OF SMALL-POX Patient vaccinated for the fir^ time seven days before onset of symptoms. Age seven years. The successful vaccination has modified exceedingly the disease, so that the papules are comparatively few in number. This boy was infected by his sister, who was unvaccinated, and had a most severe attack of small-pox. Photo taken on the sixth dav of rash. PLATE X A MODIFIED CASE OF SMALL-POX Patient vaccinated in nilancv. Ke-\accinatecl lour days before onset of disease. Age twenty-six years. This patient shows a successful re -vaccination which is typical in appearance. PLATE XI A MILD AND MODIFIED CASE OF SMALL-POX Patient vaccinated in infancy. Ke-vaccinated on tlie day after onset of symptoms. Age twenty-four years. This patient shows a vaccination which is atypical in character. PLA TE XII SEVERE ATTACK OF SMALL-POX IN A PERSON WITHOUT PRIMARY VACCINATION IN INFANCY Patient iinvaccinated in inlancy. Vaccinated lur first time un the fourth day of the disease. Age twenty-seven years. The plate shows that the eruption, as shown on the upper arm, was very profuse over the body ; the vaccination having been performed rather late was atypical and naevoid in character. Photo taken three weeks after the appearance of the rash. PLATE XIII O' """T;'' ^^'^M^H \' -^, ' i' /,*m-_i 7 c > \.^ X . A VERY MODIFIED CASE OF SMALL-POX Infantile vaccination did not take. Re-\'accinated successfully six days before onset. Age tweh'e years. This case is interesting as showing that the inflam- matory areola around the vaccination area has determined a numerous crop (A) of small-pox vesicles to appear. The rash is well marked and confined more particu- larly to the face. Photo taken on the sixth day of the rash. PLATE XIV A CASE OF SMALL-POX OF MODERATE SEVERITY The patient was a Kiissian inimi{,'rant, and had been very poorly vaccinated in infancy, the scar-area oiilv appi cixiinatinf,' one-tenth square inch. He remained critically ill for a long timr, luit ultimately recovered. Aged seventeen years. A scratch on the right hand caused by the patient breaking a pane of glass has determined a confluent crop of papules to develop on each side of the scratch. (A) Confluent crop of vesicles at scratch. PLATE XV A MILD AND MODIFIED CASE OF SMALL-POX The patient was \accinated n\ iiilancy. Re-vaccinated witliout result five days after onset of the disease. Age twenty -five years. .\ confluent eruption is seen on tlie foreliead, due to spirit compress used by the patient to reUeve headache. The patient was vaccinated five days after onset of the disease without any local result. (A) Unsuccessful attempt at vaccination. Photo taken on fifth day of the rash. PLATE 11 A CASE OF SMALL-POX OF MODERATE SEVERITY Patient vaccinated in infancy. Ke-\accinated successfully six days before erup- tion appeared. Age twenty-four years. Note that in this case the rash is more profuse than in Plate I , but the distribution is the same. The anterior triangle of neck is relatively free. The re-vaccination is well shown, and there is a charac- teristic crop of small-pox vesicles situated on the inflammatory areola around the vaccination site. Photo taken on fifth day of rash. PLATE XVI ^^^^^^^^^t^^ m- ^^^^HJ^6C i >. I ^ f A SEVERE CASE OF SMALL-POX The patient was vaccinated in infancy. Re-vaccinated without result five days after onset of disease. .\ge thirty-five years. The case shows that the disease may become very severe in those who liave lost immunity with advancing years: this patient is ten years older than that shown in Plate XV. The result of vaccina- tion was atypical and of a nsevoid character. Around the areas are irregular rings of confluent small-po.\ vesicles and pustules, which give an erroneous appearance of success. Photo taken on the eighth day of the eruption. 41 or a confluent eruption on each side of a scratch on the hand {see Plate XIV). Similar phenomena can be seen after chemical or other irritation {see Plate XV). When a vaccination has been performed, therefore, from the day of onset onwards until the rash appears, the inflammation and irritation due to the operation and the slight local reaction which occurs may cause a crop of small-pox vesicles to appear around the area. This is especially the case in severe or confluent small-pox, but may be also seen when the rash is very sparse on the rest of the body. These vesicles, especially in severe cases, may coalesce so as to form a ring around the vaccination site, and give rise to a false appearance of success of the operation {see Plates XVI and XVII). Many cases, therefore, said to be successfully vaccinated, are really due to coalescence of small-pox vesicles and pustules around the area of the vaccination. This, I am convinced, is the case ; it is only likely, however, to give rise to doubt in cases of severe or confluent small-pox where the eruption is profuse. Clinical Society's Report. — These observations were completed, when attention was drawn to a report, published in 1878, of a Committee of the Clinical Society of London, formed to investigate the periods of incubation, contagious- ness, etc., of small-pox In this report there are twenty- two cases of concurrent variola and vaccination recorded by Dr. Birdwood, of the Metropolitan Asylums Board's Hospital. These cases are incomplete in their details, but I have taken twenty of them which can fairly well be used in comparison. These have been arranged in the same type of chart as that of the present paper, and it is surprising to find a very close agreement {Chart D, page 42). It will therefore be abundantly evident from the 5 S Malaise, Fever, &c. No Rash Apparent success due to irrita- tion and inflammation at site of vaccination < u a o 5 u en f- 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 xxxx Q 'XXXXXXXXXXXXXXX ' ' 1 ' Q tJ « O fc M U cu < z o < O o < > u z o U) tn < u tn Q (1< o Q Ov 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 00 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 OS N 1 1 1 1 1 1 1 1 1 1 < 1 1 1 1 1 1 1 1 1 1 1 ^ < J 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ^ 1 1 1 c" 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 $ 1 1 1 1 ^ 1 1 1 1 1 1 1 1 1 > 1 1 1 1 1 o 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 CTi 1 1 1 1 1 1 1 1 1 1 1 1 >> 1 1 1 1 1 1 00 g 1 < 1 1 1 1 1 1 1 >>> 1 1 1 1 1 1 1 1 >> 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 >> 1 1 1 1 1 1 1 1 1 1 1 1 1 3 *" 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 __ 1 1 1 >> 1 1 1 1 1 1 1 1 1 1 1 1 1 t 1 1 >> 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 1 H 1 1 1 1 1 1 1 1 1 J 1 r J 1 1 f 1 1 1 1 ■a o ° > 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 t 1 1 w N en ^ invo t^oo ONO m n ro^mo r^oo oi o HHMMWHHHHIHN s > C/5 P I I > < S N 43 charts and photographs that the operation of vaccination performed at any time during the incubation period will be successful. This may be true even during the first period of onset, but if carried out subsequently to the initial symptoms, the vaccination will not be successful or typical in its appearance. Dr. Birdwood states that he has " only found one vaccination which was successful if vaccinated on the day of eruption or after." In my opinion, and for the reasons which have been given, the case was probably not a successful one, the appearance of success having been given by the coalescence in a confluent case of the vesicles and pustules around the inflammatory zone of vaccination. In the same report, Dr. Colclough, who was at that time Assistant Medical Officer at the hospital ships, in a note states, " In the few instances in which I have vaccinated patients on their admission, when the eruption has been in the macular or papular stages, the re- vaccination has failed, and the reports of over fifty cases of re-vaccinations (taken from the case books), in various stages of eruption, coincide with my few instances." I have often heard the statement made by medical men, that when persons have been vaccinated and the operation is not proving successful, there is a likelihood they will develop small-pox, or that these cases ought to be watched and isolated. In my opinion it is in cases recently vaccinated which show evidences that the opera- tion will probably be successful, and where there is low immunity, that small-pox is likely to develop ; these cases require to be kept under surveillance. Some time ago, a vessel arrived in Liverpool having had a case of smaU-pox on the voyage ; the man died and was buried at sea five days before reaching Liverpool. All the crew were vaccinated on arrival ; one of them, who assisted in burying 44 this man, developed a very mild rash of small-pox ten days after vaccination and the arrival of the ship ; his vaccina- tion had taken in three places, and showed typical vesicles and other associated signs. Therefore, assuming that the vaccinations have been properly performed with active lymph, the cases to be watched more particularly are those which show signs of the vaccination " taking." Influence of Concurrent Vaccination on the Course of the Disease. Another aspect of the subject may now be studied with advantage, namely, the influence of this vaccination on the course and severity of the disease {see Charts B, C, and D). The degrees of severity have been classified for con- venience into three groups : Column i represents a mild attack of the disease ; Column 2 a moderate or severe attack ; and the very severe group is recorded under Column 3 : this group also includes deaths, but these are shown individually in the body of the table. Chart B. — On an examination of the thirty cases without a primary vaccination in Chart B, it will be seen that of Cases i to 5, vaccinated within the first three days of infection, two developed no symptoms or signs of the disease, whilst three had an exceedingly mild attack after an initial malaise. In these latter onlj' a few papules appeared, which never became vesicles, but simply died away ; in these aborted cases the small-pox had just over- come the protective effect of the vaccination. Tracing the cases further on in the disease, we find that the type becomes more or less severe, according to individual susceptibility, until we come to those of 45 moderate severity, vaccinated from the seventh day of infection up to the onset ; following on this the cases vaccinated after the onset of the disease will be seen to have been of the very severe t^'pe, three of them ending fatally, showing that cases vaccinated at the stage of onset and after the rash has appeared, have much less chance of benefiting by the vaccination. Chart C. — If attention be now turned to Chart C, showing forty-five cases of small-pox with a primary vaccination in infancy, it is of interest to find that in this group the effect of the primary vaccination is shown on the course of the disease : the primary vaccination along with the re-vaccination performed concurrently has greatly assisted in modifying the severity of the disease. Further, it will be noticed that in this chart of cases which show a primary vaccination, there are no cases found vaccinated on the day of infection or on the first three days following. This may be accounted for by the fact that the double vaccination, i.e., primary and re- vaccination, has prevented the onset of symptoms or appearance of rash in persons re-vaccinated on these days, and therefore I have been unable to obtain small-pox cases to place on the chart in the position corresponding to these days ; this view is also supported by the chart of Dr. Birdwood's cases. It may be remarked, however, that the number of cases is smaU to draw such final conclusions ; still, I draw attention to the fact as being one of probably some importance from an administrative standpoint. On examining the cases re-vaccinated before the onset of symptoms, it will be seen that in nearly all the disease was of a mild or very mild type. Taking this portion, i.e., during incubation period, of the series in Chart C, there are only four cases out of twenty-seven in which the 46 eruption may be considered as of moderate or severe character. The cases vaccinated after the onset of the disease, and subsequently to the appearance of the rash, showed a more pronounced type ; in this case most of the patients had the disease in a moderate or severe form. When it is stated that the vaccination or re- vaccination was unsuccessful as an operation, it must not be understood that the modified organisms implanted in the system did not exercise any appreciable modifying effect. Case No. 28 amongst the unvaccinated (Chart B) illustrates this point. A lady, unvaccinated in infancy, contracted small-pox abroad, and was vaccinated one day after the appearance of the rash ; a slight traumatic reaction occurred at the site of vaccination, with ill-defined papule and aborted vesicle, forming a yellow crust, which was quite atypical. The case passed through a severe attack ; towards the twelfth to fourteenth day of the disease, however, when the suppurative stage ought to have been at its height, it was surprising to find the pustules rapidly drying and falling off, so that within a day or so they had entirely gone ; the resulting scars were totally absent, and only marked staining remained, which disappeared under a year, and no trace of the disease can now be seen after some years. The case was, to my mind, a convincing proof of the value of vaccination done subsequently to onset of symptoms, and the operation ought therefore to be performed on all cases admitted to hospital. Other cases, not so striking, can be quoted. The remarkable antagonism of these two diseases can only be explained by a consideration of the question of immunity or concurrent immunities. It may suffice to say that in small-pox with a concurrent vaccination, it is a 47 race between the virulent and the modified organisms ; the less virulent and the more saprophytic forms grow faster and produce immunity more quickly than the more virulent ones. Protection is not acquired at any particular time, but there is a gradual accumulation of immunity in the blood, which usually shows itself to be completed by the beginning of the second week after vaccination. It would seem from an examination of the charts, that nine days after vaccination is the period required to give real evidence of the increasing protection against small-pox. It is therefore evident that the intensity of the disease bears an inverse ratio to the period of vaccination ; the later the disease appears after vaccination, the more opportunity for the vaccination to be successful and develop its counteracting immunity; when the small-pox appears early in the course of a vaccination, the more severe is the course of the disease. On referring to Chart B of unvaccinated cases, it will be seen that cases of small-pox vaccinated within three days after infection will develop very slight or no sym- ptoms of small-pox ; and a reference to Chart C shows no cases occurring within the first three days. One may safely infer, therefore, that vaccinations performed within the first three days of infection in persons with a primary vaccination will not develop small-pox, and in those who are unvaccinated the chances are that the disease will not develop ; or, in other words, vaccination requires nine days to develop an immunity which will absolutely prevent or minimise an attack of small-pox. 48 Concurrent Cases amongst Infants. An instructive series of concurrent cases is shown in the following Chart E, with its accompanying photographs. The series sets out in tabular form seven cases of small-pox in infants with concurrent vaccination. The majority of these were born in hospital of variolous mothers, and vaccinated within a few days of infection ; two are shown to have been infected in utero. It will be seen that Cases i and 2 [Plates XVIII and XIX), infected with small-pox on the da}^ of birth and the day following respectively, were vaccinated within twenty-four hours, with entire absence of development of any symptoms or signs of the disease ; and the mothers continued to nurse these children until they were convalescent and discharged ; in these cases the vaccinations were entirely successful and absolute pro- tection was afforded. Cases 3 and 4 (Plates XX and XXI) were vaccin- ated later in the incubation period of the disease. Case 3 was vaccinated at the end of the third day of incubation, and had a very mild attack, as illustrated in the photo- graph. The eruption was very sparse and scattered, and the individual papules rapidly passed through the pre- liminary stages to pustulation ; this is one of the charac- teristic effects of vaccination. Case 4 was vaccinated on the fourth day of incubation, and had a very mild attack. Case 5 {Plate XXII) was vaccinated on the fifth day of incubation, the day following its birth, and showed a more profuse eruption of small-pox. This baby was infected in utero. The mother's rash appeared on December 12th, while the child's eruption appeared on December 27th, exactly fifteen days later. 49 Case 6 (Plate XXIII), four months old, and un- vaccinated, was infected with small-pox on March 30th ; owing to various circumstances in connection with the illness of the mother and consequent delay in the reporting of the case, the baby was not vaccinated until the eighth day after infection; the eruption was profuse, but complete recovery took place. Case 7 was a baby infected on February 28th in utero. The mother's rash appeared on that day; the child was born on March 6th and vaccinated on March gth. The disease was of very severe type and death ensued. The vaccination in this case was carried out too late to have an opportunity of neutralizing or modifying the course of the small-pox. Without undue repetition of perfectly obvious facts, it will not be out of place to again point out that the non-development of small-pox or its extraordinarily mild character in those infants of the above series which were vaccinated in good time, contrasts markedly with what is shown in Chart A {page 16), as occurring amongst unvaccinated children, where a 50 per cent mortality is shown as a result of the neglect of this obvious precaution. Fortunately it has been possible to insert two plates {XXIV and XXV), which will bear out the above obser- vation and serve as contrasts with the foregoing series. E i ^l,Ni Q £ o * z < >^ Z ° .2 < z < -^ -J u 2 < < X > H Z UJ Q^ D O z o w)3 O J: X — " bB : CO c : HV : 2 -2 .£ « ,0 -c ■5" *! "-' -T 4- Uj ^ > ^ ^ , ■ x< * ^ ^ \ a \ Si \ A \ \ 4 ;\ Ij \ ll \ , 1 \-= = 1 *-l »!M = 1 ■^ \^ z\ \i = 1 ^' / ^ - \ ji ^ ',- M A^ y '1 qI ,C^ jl 11 /? CN /;f ' = 1 / 1 1 ' i 7' 1 / 5 -) ' ' ■ '' i =li 5 g ■S'b pa)nui03B/i !_ ^ ■ifjog CN ■luog ■ii.iog .£ 1 na 5 °!: 1 ■^ uJ ■^-"^ S J 0° ^ ill ^ CO ES5 < to ££5 ■= CO c£o ^ laSm ' < ias« -: < «S• o ^ < tt'ii - O r PLATE XVII A SEVERE CASE OF SMALL-POX, UNVACCINATED IN INFANCY The patient was vaccinated for the first time unsuccessfully three days after onset of symptoms and after the appearance of the rash. Age forty-three years. The result of the vaccination has been unsuccessful, and the appearance of the vaccination areas compares with Plate XVI. Photo taken on the sixth day of the eruption. PLATE XV 1 11 l.-A CHILD SUCCESSFULLY VACCINATED ON THE DAY OF BIRTH AND NURSED BY ITS MOTHER. WHO HAD SMALL-POX. THROUGH- OUT HER ILLNESS OF SIX WEEKS IN A SMALL-POX HOSPITAL Child born January 15th, vaccinated successfullv on January 16th. Mother developed small-pox rash on January 16th, and nursed her child in hospital until discharged. No development occurred in the child. PLA TE XIX -MOTHER SUFFERING FROM SMALL-POX NURSING HER SUCCESSFULLY VACCINATED BABY Mother aged twenty-five years. Vaccinated in infancy. Baby born in hospital and successfully vaccinated on the following day. No signs or symptoms of small-pox appeared in the child, which was nursed by the mother throughout her own illness in hospital, and discharged after si.\ weeks. (A) Infant's successful vaccination. Photo taken on the ninth day of the vaccination. PLATE XX. -AN EXCEEDINGLY MILD AND MODIFIED ATTACK OF SMALL-POX Child born April I'Jth, vaccinated successfully April -!ind, three days after infection. Mother developed small-pox rash on April 19th, and nursed the child throughout her illness. The baby developed a small number (twenty) of small- pox papules scattered on its body. Photo taken on the third day of the rash. PLATE XXI Case 4— A VERY MILD AND MODIFIED CASE OF SMALL-POX Child aged three months, was vaccinated successfully four days after infection with small-pox, i.e., eight days before onset. The child developed a very mild attack of small-pox; not more than eight or nine papules on the face, and about twenty on the body. PLATE XXII -ANOTHER CASE OF MILD SMALL-POX IN AN INFANT SUCCESSFULLY VACCINATED BEFORE ONSET Child aged fifteen days, born on December 16th, and successfully vaccinated five days after infection from the mother, whose rash appeared on December 12th. The child de\'eloped a mild attack of small-pox with sparse eruption. It will be noticed that the later the day of vaccination after infection, the more severe the character of the disease. Compare Plates A'.V, XXI, and XXHl. Photo taken on sixth day of the rash. PLATE XXIII .-ANOTHER CHILD. SHOWING A MILD AND MODIFIED ATTACK OF SMALL-POX. AND VACCINATED FOUR DAYS BEFORE ONSET Child aged four months, was successfully vaccinated eight days after infection with small-pox. The patient developed a modified attack of small-pox, but the eruption was much more numerous and pronounced, and papules of larger size, than in any of the previous cases. Photo taken on eighth day of the rash. iV o_, ■0-3 J2 J) < - qs 3 T3 „ 51 Conclusions. The following conclusions may be drawn from the Part I :— {a). That the case mortality in the natural disease, i.e., in the un vaccinated, which ranges from approximately 25 to 40 per cent, has been reduced by the power of vaccination to about 3 per cent in those who have been well vaccinated. [b). That in the unvaccinated, persons at the extremes of life, mainly children under 10 years of age and old people, are those who suffer most, the case mortality reaching as high as 50 per cent. In the previously vaccinated, no cases are recorded occurring under three years of age; under twenty years of age no deaths are recorded, but as age advances the vaccination gradually loses its protective and modifying power. (c). That even when, owing to age, and consequent gradual loss of vaccinal immunity, vaccination ' is unable to stop the development of the disease, it may modify the extent and character of the eruption to such a degree as to make it so exceedingly mild that in many instances the disease may be undetected. \ 7 52 Pari II :— [d). That the scar-area of vaccination has an important bearing on the severity of the disease ; the larger the area, the milder the character of the disease. [e). That the vaccination scar-area gets larger as age advances until the 20-30 years age-period is reached ; it then gradually becomes smaller, in all probabiUty owing to atrophy of the scar tissues. Part III :— (/). That vaccination performed subsequentlj^ to infection with small-pox and up to the date of onset of symptoms will " take " and pass through its typical course. (g). That protection is afforded against small-pox by vaccination when performed within three days after infection, but this may not be absolute in cases vaccinated for the first time ; the course of the disease, however, will be exceedingly mild. {h). That there is abundant evidence of the value of vaccination in mitigating the severity of the disease when performed at any time after infection up to date of onset, and even after- wards. >-■ RETURN TO the circulation desk of any University of California Library or to the NORTHERN REGIONAL LIBRARY FACILITY BIdg. 400, Richmond Field Station University of California Richmond, CA 94804-4698 ALL BOOKS MAY BE RECALLED AFTER 7 DAYS • 2-month loans may be renewed by calling (510)642-6753 • 1-year loans may be recharged by bringing books to NRLF • Renewals and recharges may be made 4 days prior to due date DUE AS STAMPED BELOW DEC 23 2003 DD20 15M 4-02