id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-335375-n6q70o35	Chan, Paul K. S.	Antibody Avidity Maturation during Severe Acute Respiratory Syndrome–Associated Coronavirus Infection	2005-07-01		.txt	text/plain	2186	109	55	Samples collected р50 days after fever onset were also tested for anti-SARS-CoV IgM antibody, so that IgM antibody detection and IgG antibody avidity measurement could be compared with respect to demonstrating a recent infection. Changes in severe acute respiratory syndrome-associated coronavirus-specific IgG antibody avidity in paired serum samples ples were measured by an in-house indirect immunofluorescence assay that has been described elsewhere [12] . Of the 45 samples collected р50 days after fever onset, only 18 (40.0%) were positive for anti-SARS-CoV IgM antibody, as determined by the ELISARS assay. Of the 26 paired samples, only 6 (23.1%) showed a significant (у4-fold) increase in anti-SARS-CoV IgG antibody titer (as determined by an in-house indirect immunofluorescence assay) from the first to the second sample, a result that could be regarded as evidence of recent infection. Our data show that anti-SARS-CoV IgG antibody avidity is low during primary infection and increases with time in a unidirectional manner.	./cache/cord-335375-n6q70o35.txt	./txt/cord-335375-n6q70o35.txt