Reference:
Gazit, S., Shlezinger, R., Perez, G., Lotan, R., Peretz, A., Ben-Tov, A., Cohen, D., Muhsen, K., Chodick, G., & Patalon, T. (2021). Comparing SARS-CoV-2 natural immunity to
vaccine-induced immunity: reinfections versus breakthrough infections. medRxiv. https://doi.org/10.1101/2021.08.24.21262415
Summary:
This study compares the long-term protection provided by natural immunity from previous SARS-CoV-2 infection to that from the BioNTech/Pfizer mRNA vaccine. Conducting a retrospective analysis of three cohorts—naïve vaccinated individuals, previously infected unvaccinated individuals, and those previously infected and vaccinated—the authors examined the incidence of breakthrough infections and reinfections during the Delta variant’s dominance in Israel. Results indicated that vaccinees had a significantly higher risk of breakthrough infections (13.06-fold) and symptomatic disease compared to those with natural immunity. The findings suggest that natural immunity offers more robust and enduring protection against reinfections than vaccine-induced immunity, although vaccinated individuals who had prior infections gained additional benefits. The study highlights the importance of understanding immunity dynamics to inform public health policies and vaccination strategies.