Pfizer has said its vaccine continues to be effective against Covid-19 up to six months later, citing updated trial data.
Pfizer and its German partner, BioNTech, announced updated results Thursday from their ongoing late-stage study of more than 44,000 volunteers.
The vaccine remains more than 91% effective against disease with any symptoms for six months, the companies said. And it appeared to be fully effective against the worrying B.1.351 variant of the virus, which is the dominant strain circulating in South Africa and which researchers feared had evolved to evade the protection of vaccines, the companies said.
Of 927 confirmed Covid-19 cases detected through March 13, 77 were among people who received the vaccine and 850 were among people who got dummy shots.
“The vaccine was 100% effective against severe disease as defined by the U.S. Centers for Disease Control and Prevention (CDC), and 95.3% effective against severe COVID-19 as defined by the U.S. Food and Drug Administration (FDA),” Pfizer and BioNTech said in a joint statement.
On Wednesday, the companies said a small trial of volunteers aged12 to 15 showed 100% efficacy in that age group.
“These data confirm the favorable efficacy and safety profile of our vaccine and position us to submit a Biologics License Application to the U.S. FDA,” Albert Bourla, Pfizer’s chairman and chief executive officer, said in a statement. A BLA is an application for full approval. The vaccine currently has emergency use authorization, EUA, which falls short of full approval.
“The high vaccine efficacy observed through up to six months following a second dose and against the variant prevalent in South Africa provides further confidence in our vaccine’s overall effectiveness.”
The UK and US gave the emergency green light to roll out Pfizer’s vaccine late last year followed by many other countries.