SARS-CoV-2 Immunogenicity in individuals infected before and after COVID-19 vaccination: Israel, January-March 2021: Implications for vaccination policy

Between December 2020-March 2021 we measured anti-SARS-CoV-2 IgG titers post-vaccination with the BNT162b2 vaccine among 725 Israeli hospital workers. Previously infected individuals who received one dose had higher IgG titres than fully vaccinated, never-infected workers. Post-vaccination infection did not increase IgG titres. Individuals infected post-dose one should receive the second.