Study investigates the efficacy of COVID-19 vaccines over longer term
"Ongoing trials of #COVID19 vaccines were not designed to estimate how well they prevent infections, particularly asymptomatic infection. As a result, we don't know if being vaccinated reduces the need to wear masks or socially distance."
COVID-19 vaccines were designed to reduce the likelihood that infection by the SARS-CoV-2 virus would lead to severe outcomes, such as hospitalization and death. In that sense, all of the currently approved vaccines -- Moderna, Pfizer and Johnson & Johnson -- have proven comparably effective.
But much less is known about the actual ability of these vaccines to prevent infection, most notably asymptomatic cases in which vaccinated persons might not become ill or display symptoms, but could still carry sufficient levels of the virus to pose a potential transmission threat to others.
New research is beginning to fill this knowledge gap