Fig. 1: Escape of BA.4 and BA.5 from BA.1 elicited immunity in unvaccinated participants.
From: Omicron BA.4/BA.5 escape neutralizing immunity elicited by BA.1 infection
a Daily Covid-19 cases (purple, left axis) and excess deaths (orange, right axis) in South Africa. b Combined fraction of BA.4 and BA.5 in South Africa and the US according to GISAID deposited sequence data. Prevalence was calculated by dividing the number of submitted BA.4 and BA.5 sequences by total submitted sequences per 2-week period starting February 15, 2022. c Percentage of South Africans vaccinated over time. d Neutralization of BA.4 and BA.5 compared to BA.1 virus by BA.1 infection elicited neutralizing immunity in n = 24 unvaccinated participants. Numbers are geometric mean titer (GMT) FRNT50. Dashed line is most concentrated plasma tested. e Geometric mean (GM) of fold-drops in neutralization and their 95% confidence intervals for BA.4 and BA.5 relative to BA.1 calculated from (d). For panels (d) and (e), orange points represent BA.1, yellow BA.4, and pink BA.5. p-values were determined by a two-sided Wilcoxon rank sum test and represented as ***0.001-0.0001. Exact p-values were 4.4 × 10−4 for both BA.4 and BA.5. Source data are provided as a Source Data file.
