. 2023 Sep 25;41:100911. doi: 10.1016/j.lanwpc.2023.100911

Table 2.

Protective effect of the prior infection against the reinfection with BA.5.

Variant of the first infection	Uninfected with BA.5	First infection	Infection with BA.5	Absolute risk	Relative Risk	Protection effectiveness (1−RR) (%)
Variant of the first infection	106,315,551	–	8,680,807	Absolute risk	Relative Risk	Protection effectiveness (1−RR) (%)
Wuhan		410,783	18,036	0.044	0.54	46.2
Alpha		297,250	15,728	0.053	0.65	35.2
Delta		670,702	32,515	0.048	0.59	40.6
BA.1/BA.2		6,949,419	148,235	0.021	0.26	73.9
Any variants		8,328,154	214,514	0.026	0.32	68.5