COVID-19 vaccine provided strong long-term protection against the virus in a late-stage study conducted among adolescents aged 12 to 15 years.A two-dose series of the vaccine was 100% effective against COVID-19, measured seven days through over four months after the second dose, the company said in a press release.
Among 2,228 participants in the clinical trial, there were 30 confirmed cases of symptomatic COVID-19 – all among placebo recipients, and none in the group that had received the vaccine.