By Andrea Hargraves 
A Brazilian study published in The Lancet – Infectious Diseases shows new evidence that people who have already contracted Covid-19 and been vaccinated gain more protection against new symptoms, hospitalizations and deaths.
The research, conducted by researchers at the Oswaldo Cruz Foundation (Viocruz), found that all four vaccines available in the country – Pfizer, AstraZeneca, Coronavac and Janssen – provide significant additional protection for people who have contracted Covid within up to three months. Evaluation of immune response began 14 days after application of the second dose.
The scientists analyzed data from 213,457 people with symptoms of the disease between February 24, 2020 and November 11, 2021.
“Hybrid immunity” – as the immune response via vaccines is called infection – was better between those vaccinated with Pfizer and AstraZeneca, with 90% protection against hospitalization or death 14 days or more after the second dose. Coronavac showed protection with 81.3% and Janssen with 57.7%.
Vaccine efficacy against symptomatic infection was lower at 64.8% for Pfizer, 56% for AstraZeneca, 44% for Janssen and 39.4% for Coronavac.
The four vaccines provided additional protection against symptomatic infections and severe outcomes in individuals previously infected with SARS-CoV-2. In an article published in The Lancet, the study authors wrote that providing a full range of vaccines to individuals after recovery from Covid-19 can reduce morbidity and mortality.