To address this question, Cerqueira-Silva et al. analysed the national disease surveillance and vaccination databases from Brazil to estimate the effectiveness of CoronaVac, ChAdOx1 nCoV-19, BNT162b2 and Ad26.COV2.S in individuals with previous SARS-CoV-2 infection. All four vaccines conferred a high degree of protection against second symptomatic infections (ranging from 39.4% (CoronaVac) to 64.8% (BNT162b2)) and death (>80% for all two-dose vaccines) in previously infected individuals. Another study by Nordström et al. of Swedish nationwide registers also found that ‘hybrid immunity’ (from both infection and vaccination) provided additional protection compared to virus-induced immunity alone.
Authors: Thiago Cerqueira-Silva; Jason R Andrews; Viviane S Boaventura; Otavio T Ranzani; Vinicius de Araújo Oliveira; Enny S Paixão; Juracy Bertoldo Júnior; Tales Mota Machado; Matt D T Hitchings; Murilo Dorion; Margaret L Lind; Gerson O Penna; Derek A T Cummings; Natalie E Dean; Guilherme Loureiro Werneck; Neil Pearce; Mauricio L Barreto; Albert I Ko; Julio Croda; Manoel Barral-Netto Journal: Lancet Infect Dis Date: 2022-04-01 Impact factor: 71.421