Effectiveness of a second dose of an mRNA vaccine against SARS-CoV-2 Omicron infection in individuals previously infected by other variants.

ABSTRACT:

Background

Single-dose vaccination was widely recommended in the pre-Omicron era for persons with previous SARS-CoV-2 infection. The effectiveness of a second vaccine dose in this group in the Omicron era is unknown.

Methods

We linked nationwide population registries in Spain to identify community-dwelling individuals aged 18-64, with a positive SARS-CoV-2 test before single-dose mRNA vaccination (mRNA-1273 or BNT162b2). Every day between January 3 and February 6, 2022 we matched 1:1 individuals receiving a second mRNA vaccine-dose and controls on sex, age, province, first dose type and time, month of primary infection and number of previous tests. We then estimated Kaplan-Meier risks of confirmed SARS-CoV-2 reinfection. We performed a similar analysis in a Delta-dominant pe

SUBMITTER: Monge S 

PROVIDER: S-EPMC9214148 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature