By Antonella Macerollo
For June 2021, we have selected the following paper: Dagan N. et al. BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting. N Engl J Med 2021; 384:1412-1423. doi: 10.1056/NEJMoa2101765.
Our Covid-19 paper this month is focused on the effectiveness of BNT162b2 mRNA Covid-19 Vaccine. The worldwide pandemic situation has brought several research teams to develop vaccines against Covid-19 in a short interval of time. However, the vaccine effectiveness has not yet been assessed for a range of outcomes across diverse populations in a noncontrolled setting. Our Covid-19 authors of the month studied data from Israel’s largest health care organisation to investigate the efficacy of the BNT162b2 mRNA Covid-19 Vaccine.
The study recruited 596,618 vaccinated people during the period from December 2020 to February 2021 and matched them to 596,618 unvaccinated people. Our authors of the month studied the following outcomes at days 14 through 20 after the first dose and at 7 or more days after the second dose: documented Covid-19 infection, symptomatic Covid-19, Covid-19–related hospitalisation, severe illness and death.
The vaccine effectiveness was evaluated as one minus the risk ratio for each outcome through the Kaplan–Meier estimator.
The efficacy of the vaccine was 46% after the first dose and 92% after the second dose for documented infection; 57% and 94% for symptomatic Covid-19; 74% and 87% for hospitalization; 62% and 92% for severe disease.
The vaccine showed a 72% of efficacy in preventing death from Covid-19 for days 14 through 20 after the first dose and 84% after the second dose. Overall, our study of the month conducted in a nationwide mass vaccination setting suggested that the BNT162b2 mRNA vaccine is effective for a wide range of Covid-19–related outcomes.