The rate and influencing factors of SARS-CoV-2 Reinfection: systematic
review and meta-analysis
Abstract
Background: Understanding the SARS-COV-2 reinfection rate and its
potential influencing factors is essential for further improvement and
development of prevention and control strategies and measures to reduce
the reinfection rate of SARS-CoV-2. This study aimed to quantitatively
summarize the evidence of current reinfection studies. Methods: We
reviewed all English studies published up to Dec 4, 2022. Information
extracted from each selected articles and quality assessment of these
articles was used to evaluate the risk for bias in studies. The
meta-analysis was performed to examine the rate and influencing factors
of SARS-CoV-2 reinfection and protective effect of primary infection on
reinfection in our study. Sources of heterogeneity were identified using
a subgroup analysis defined by the minimum time interval of days to
reinfection and variant strains. Results: The weighted pooled rate of
reinfection for SARS-CoV-2 was 1.08% ([95% CI, 0.77%-1.52%], I2
= 100%, P < 0.001). Subgroup-analysis of the minimum time
interval definition for reinfection showed that rates of reinfection are
0.71%, 0.75%, 1.46% and 1.62% in less than 90 days, 90 days, greater
than 90 days, unknown groups, respectively and
0.64%,1.8%,3.08%,0.95% in Alpha, Delta, Omicron, unknown groups. The
weighted pooled RR value of the protective effect of primary infection
on reinfection was 0.09 ([95% CI, 0.06-0.13], I2 = 92%, P
< 0.01). Conclusions: Overall, the reinfection rate of
SARS-CoV-2 is relatively low and appears to be on the rise as duration
from the first infection to the second infection and the novel
coronavirus strain mutates.