Pfizer is studying whether its vaccine is effective in asymptomatic COVID-19 cases, the head of its vaccine research said Thursday.
Kathrin Jansen, senior vice president, said results could be completed in early 2021.
“Our trial was designed not just to look for symptomatic COVID-19 but also to monitor and explore whether our vaccine is efficacious against asymptomatic infection,” she told an advisory panel to the US Food and Drug Administration.
Jansen said trial participants are undergoing serological tests that measure exposure to SARS-CoV-2, the virus that causes COVID-19.
Pfizer presented findings of its vaccine study — which showed it was 95 percent effective in 43,448 recipients that received the two-dose shot — to the panel of FDA advisors who will vote Thursday on whether the agency should issue emergency use authorization of the drug.
Pfizer and BioNTech applied for emergency use authorization last month.
In a 53-page report released Tuesday, the companies said their vaccine candidate showed no safety risks.
The UK became the first country to roll out a coronavirus vaccine and began to administer the one by Pfizer/BioNTech on Tuesday.