Predictors of reinfection with pre-Omicron and Omicron variants of concern among individuals who recovered from COVID-19 in the first year of the pandemic

Dani Cohen*, Marina Izak, Evgeniy Stoyanov, Michal Mandelboim, Saritte Perlman, Yonatan Amir, Sophy Goren, Anya Bialik, Limor Kliker, Nofar Atari, Ruti Yshai, Yona Zaide, Hadar Marcus, Noa Madar-Balakirski, Tomer Israely, Nir Paran, Oren Zimhony, Eilat Shinar, Yasmin Maor, Khitam Muhsen

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Objectives: The predictors of SARS-CoV-2 reinfection are unclear. We examined predictors of reinfection with pre-Omicron and Omicron variants among COVID-19-recovered individuals. Methods: Randomly selected COVID-19-recovered patients (N = 1004) who donated convalescent plasma during 2020 were interviewed between August 2021 and March 2022 regarding COVID-19 vaccination and laboratory-proven reinfection. The sera from 224 (22.3%) participants were tested for antispike (anti-S) immunoglobulin G and neutralizing antibodies. Results: The participants’ median age was 31.1 years (78.6% males). The overall reinfection incidence rate was 12.8%; 2.7% versus 21.6% for the pre-Omicron (mostly Delta) versus Omicron variants. Negative associations were found between fever during the first illness and pre-Omicron reinfection: relative risk 0.29 (95% confidence interval 0.09-0.94), high anti-N level at first illness and Omicron reinfection: 0.53 (0.33-0.85), and overall reinfection: 0.56 (0.37-0.84), as well as between subsequent COVID-19 vaccination with the BNT162b2 vaccine and pre-Omicron 0.15 (0.07-0.32), Omicron 0.48 (0.25-0.45), and overall reinfections 0.38 (0.25-0.58). These variables significantly correlated with immunoglobulin G anti-S follow-up levels. High pre-existing anti-S binding and neutralizing antibody levels against the SARS-CoV-2 Wuhan and Alpha strains predicted protection against Omicron reinfections. Conclusion: Strong immune responses after the first COVID-19 infection and subsequent vaccination with the BNT162b2 vaccine provided cross-protection against reinfections with the Delta and Omicron variants.

Original languageEnglish
Pages (from-to)72-79
Number of pages8
JournalInternational Journal of Infectious Diseases
StatePublished - Jul 2023


FundersFunder number
SodaStream International Ltd
Wolfson Medical Center0074-WOMC
Tel Aviv University0003409-1


    • Hybrid immunity
    • Longitudinal study
    • Omicron
    • Pre-omicron variants
    • Reinfection


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