key: cord-0960433-gyp4tajs authors: Kapoor, A.; Kapoor, K. M. title: A Simple Mathematical Tool to Help Distribute Doses of Two-Dose Covid-19 Vaccines among Non-Immunized and Partly-Immunized Population date: 2021-05-12 journal: nan DOI: 10.1101/2021.05.10.21256978 sha: 958353e2764f50251b0620295de9a7f1af2a8b62 doc_id: 960433 cord_uid: gyp4tajs Background: Full immunization with two doses of Covid vaccine has been found to be a critical factor in preventing morbidity and mortality from the Covid-19 infection. However, due to the shortage of vaccines, a significant portion of the population is not getting vaccination in many countries. Also, the distribution of vaccine doses between prospective first dose recipient and second dose recipient is not uniformly planned, as seen in India's various states and union territories. It is recommended to give second vaccine doses within 4-8 weeks to first dose recipients for both the approved vaccines in India; hence the judicious distribution between non-immunized and partly immunized populations is essential. Managing the Covid-19 vaccination drive in an area with a large number of single-dose recipients compared to a smaller number of fully immunized people can become a huge administrative challenge. Therefore, this study was conducted to assess the number of people covered under the Covid vaccination drive in India and analyze the state-wise distribution of vaccines among the non-immunized and partly immunized population. Methods: The Covid 19 vaccination data till 7th may, 2021 was taken from the website of the Ministry of Health and Family Welfare, Govt of India. From the data available of the number of doses injected, other figures like the total number of people vaccinated, people with two doses of vaccine or full immunization (FI), and those with a single dose of vaccine or partial immunization (PI) were found. The percentage of the fully immunized and partly immunized population was also found. A ratio between fully immunized and partly immunized individuals (FI: PI) was proposed as a guide to monitor the progress of the vaccination and future dose distribution of two-dose Covid-19 vaccines among partly immunized (PI) and non-immunized (NI) population. Results: In India, till 7 May 2021, 16,49,73,058 doses of Covid-19 vaccines have been injected. A total of 13,20,87,824 people received these vaccine doses, with 9,92,02,590 people getting a single dose or were partly immunized (PI), and 3,28,85,234 got two doses each or were fully immunized (FI). Among the states, Tripura and Andhra Pradesh had the highest FI: PI (Fully Immunized: Partly Immunized) ratio of 0.86 and 0.52, followed by Tamil Nadu, Arunachal Pradesh, and West Bengal with figures of 0.48. 0.47 and 0.47, respectively. Telangana and Punjab had the lowest FI: PI ratio among the states at 0.2 each, with Chhattisgarh, Madhya Pradesh, and Haryana following at 0.21. 0.23 and 0.23, respectively. These values are much lower than the national average of 0.33 in India. Conclusion: The FI: PI ratio could help governments decide how to use scarce vaccine resources among first-time and second-time recipients. This simple mathematical tool could ensure full immunization status to maximum people within the recommended 4-8 week time window after the first dose to avoid a large population group with partly immunized status. other figures like the total number of people vaccinated, people with two doses of vaccine or full immunization (FI), and those with a single dose of vaccine or partial immunization (PI) were found. The percentage of the fully immunized and partly immunized population was also found. A ratio between fully immunized and partly immunized individuals (FI: PI) was proposed as a guide to monitor the progress of the vaccination and future dose distribution of 'two-dose' Covid-19 vaccines among partly immunized (PI) and non-immunized (NI) population. The covid vaccine has been found to be a critical factor in preventing morbidity and mortality from the Covid-19 infection 1 2 3 . Globally, the governments are trying to immunize their people as fast as possible to achieve maximum population coverage. For the Covid-19 vaccination drive to be effective, three things need to be planned: supply of vaccines, people needed to implement vaccination, and distribution among people to be vaccinated. If there is a mismatch in these factors, failure of the vaccination drive is inevitable. 4 As the pace of the COVID-19 campaign in India is being driven by vaccine supplies, . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted May 12, 2021. ; https://doi.org/10.1101/2021.05.10.21256978 doi: medRxiv preprint distribution between non-immunized and partly immunized people assumes significance for the success of the Covid-19 vaccination drive. It is recommended to give a second dose of the Covid-19 vaccine within 4-8 weeks of the first dose, so it is crucial to distribute the vaccine doses among the nonimmunized and partly immunized population. Having many more partly immunized people than fully immunized people in a geographical area can lead to many problems in the vaccination drive against Covid-19. This study was conducted on Indian vaccination data to find a simple mathematical tool that could help distribute Covid-19 vaccine doses among the non-immunized and partly immunized population. The national and state & union territories data of Covid 19 vaccination in India till 7 am of 7 th may, 2021 was taken from the official website of Ministry of Health and Family Welfare, Govt of India. (https://www.mohfw.gov.in/pdf/CumulativeCOVIDVaccinationCoverageReport06052021.pdf) The data gets updated every day. The data presented the national and state-wise total number of doses injected, the total number of single doses injected, and a total number of second doses injected. From the data available about the number of doses injected, other figures like the total number of people vaccinated, people with two doses of vaccine or full immunization (FI), and people with one dose of vaccine or partial immunization (PI) were found. The percentage of fully immunized and partly immunized was also calculated among the vaccine beneficiaries. A ratio between fully immunized and partly immunized individuals (FI: PI) was calculated and proposed as a simple guide to monitoring the progress of the vaccination and dose distribution of 'two-dose' Covid-19 vaccines among partly immunized (PI) and non-immunized (NI) population. No ethics board approval was needed for this research paper, as this information was available in the public domain. In India, till 7 May, 16,49,73,058 doses of Covid-19 vaccines have been injected. A total of 13,20,87,824 people received these vaccine doses, with 9,92,02,590 people getting a single dose or were partly immunized (PI), as shown in Table I. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted May 12, 2021. ; https://doi.org/10.1101/2021.05.10.21256978 doi: medRxiv preprint A total of 3,28,85,234 people got two doses each or were fully immunized (FI). The population not covered under any of these groups was categorized as non-immunized ( NI). The same data was worked out for every state and union territory as given in Table II. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted May 12, 2021. ; https://doi.org/10.1101/2021.05.10.21256978 doi: medRxiv preprint . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The Miscellaneous group had the highest FI: PI ratio of 4.07 value. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted May 12, 2021. ; https://doi.org/10.1101/2021.05.10.21256978 doi: medRxiv preprint The Covid -19 pandemic prompted scientists across the globe to design possible alternative COVID-19 vaccines 5 . Full immunization with two doses of Covid vaccine has been found to be a critical factor in preventing morbidity and mortality from the Covid-19 infection 1 . Globally the governments are trying to immunize their people as fast as possible to achieve maximum population coverage. The best strategy is to quickly deliver vaccines to as large a part of the population as possible and identify and tackle vaccine hesitancy sources 6 . This strategy would maximize the individual and population benefits of the approved COVID-19 vaccines. 7 However, due to the shortage of vaccines in some countries, a significant number of the population is not getting access to vaccination 8 11 12 In April 2021, Sputnik V from Russia was also approved as a third vaccine, with its use expected to begin by late May 2021. As per the Centre for Disease Control and Prevention (CDC), immunization is 'a process by which a person becomes protected against a disease through vaccination.' This term is frequently used interchangeably with vaccination. In this study, people who received two doses of the vaccine were . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The danger of having a low FI: PI ratio in a geographic area is that there would be many more people with partial immunized than fully immunized people. Continuing to inject the first dose recipient may lead to a situation where the second dose recipient would miss out on their dose in 4-8 weeks. The gains associated with enrolling people for the first vaccine dose are also partly lost if the gap becomes very long before the second dose. This situation poses the following possible challenges in the vaccination drive against • There is a concern that people with only one dose might believe that they have adequate protection against COVID-19 infection, and they do not need the second dose. There is no evidence to show that people getting only one dose have adequate long-term protection against COVID-19 infection. 14 • The potential risk from delaying the second dose of the Covid vaccine is that the second dose will be less effective when given later than the recommended interval. • Also, many people who got their first vaccine may forget to return for their second dose after a long delay between the first and second dose. • There is also a possibility that some people will be confused by regular changes in the vaccine schedule, and the resulting confusion may drive them to shun vaccination altogether or make them believe that they need a single dose only. • Finally, some experts have warned that partial immunization with a single dose can lead to a less robust immune response giving only partial immunity against COVID-19 infection. • Partial immunization may result in a greater risk that vaccine-resistant variants of SARS-CoV-2 could develop. Many countries, including India, have a short time window available to take some decisive actions, and the vaccination drive could become a success story or a failure. Using a simple mathematical tool like FI: PI ratio for vaccine distribution is likely to make dose distribution between partly immunized and non-immunized people transparent and easily replicated across all the states. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted May 12, 2021. ; https://doi.org/10.1101/2021.05.10.21256978 doi: medRxiv preprint Limitations: 1.The FI: PI ratio is not much relevant in single-dose Covid vaccines. It shows that there is a great need to develop single-dose vaccines to achieve fast population coverage. 2. In the absence of scarcity of doses and ample vaccine supply, the role of the FI: PI ratio is slightly less critical as coverage of non-immunized and partly immunized people can go on simultaneously. However, the FI: PI ratio still has a role in keeping a tract of partly immunized people to fully immunized ones. Vaccination coverage against Covid-19 in India needs much improvement at this point. The vaccine distribution in different states and union territories of the country is also not uniform. As a simple mathematical tool, the FI: PI ratio could help the governments decide how to use scarce Covid-19 vaccine resources among first-time and second-time recipients. This information can also help the government make changes in the vaccine booking app where the definitive assignment of slots among first-time and second-time recipients could control the FI: PI ratio. This method is likely to ensure full immunization status for maximum people within the prescribed 4-8 weeks after the first dose of Covid vaccine to avoid challenges posed by having a large population group with partly immunization status. Reduction in COVID-19 Patients Requiring Mechanical Ventilation Following Implementation of a National COVID-19 Vaccination Program -Israel The impact of vaccination on COVID-19 outbreaks in the United States. medRxiv The Influence of Covid-19 Vaccine on Daily Cases, Hospitalization, and Death . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) Rate in Tennessee: A Case Study in the United States. medRxiv The challenges of distributing COVID-19 vaccinations COVID-19 vaccines: where we stand and challenges ahead Dealing with vaccine hesitancy in Africa: the prospective COVID-19 vaccine context Vaccine: Implementation Over Efficacy Access to and equitable distribution of COVID-19 vaccine in low-income countries. npj Vaccines Antibody Response after First-dose of ChAdOx1-nCOV (Covishield TM ®®) amongst Health Care Workers in India: Preliminary Results of Cross-sectional Coronavirus Vaccine-induced Antibody Titre (COVAT) study. medRxiv AZD1222 (Covishield) vaccination for COVID-19 Experiences, challenges, and solutions in Nepal Covid-19: India is at centre of global vaccine manufacturing, but opacity threatens public trust Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBV152: interim results from a double-blind, randomised, multicentre, phase 2 trial, and 3-month follow-up of a double-blind, randomised phase 1 trial Abbreviations: FI-fully immunized, PI-partly immunized, NI-non-immunized The copyright holder for this preprint this version posted May 12, 2021 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted May 12, 2021. ; https://doi.org/10.1101/2021.05.10.21256978 doi: medRxiv preprint