Pfizer-BioNTech COVID-19 Vaccine 100% Effective in Adolescents

March 31, 2021 - Pfizer and BioNTech recently announced that its COVID-19 vaccine, BNT162b2, demonstrated 100 percent efficacy and robust antibody responses in adolescents with or without prior SARS-CoV-2 infection.

The Phase 3 trial enrolled 2,260 adolescents 12 to 15 years of age in the US. In the trial, 18 cases of COVID-19 were observed in the placebo group versus none in the vaccinated group. 

Although overall results exceeded those recorded earlier in vaccinated participants aged 16 to 25 years of age, BNT162b2 demonstrated strong immunogenicity in a subset of adolescents one month after the second dose. This is comparable to geometric mean titers (GMTs) elicited by participants aged 16 to 25 years of age in the earlier analysis. 

Side effects were generally consistent in participants 16 to 25 years of age as well.

“Across the globe, we are longing for a normal life. This is especially true for our children. The initial results we have seen in the adolescent studies suggest that children are particularly well protected by vaccination, which is very encouraging given the trends we have seen in recent weeks regarding the spread of the B.1.1.7 UK variant,” Ugur Sahin, CEO and Cc-founder of BioNTech, said in the announcement.

“It is very important to enable them to get back to everyday school life and to meet friends and family while protecting them and their loved ones,” Sahin continued. 

Last week, Pfizer and BioNTech dosed the first children in a global Phase 1/2/3 study to further evaluate the safety, tolerability, and immunogenicity of BNT162b2. 

The vaccine was given 21 days apart in three age groups: children five to 11 years old, children two to five years old, and children six months to two years old. 

The five to 11 group began dosing last week, while the two to five year old group will be dosed next week.

Pfizer and BioNTech plan to submit these data to FDA and the European Medicines Agency (EMA) as soon as possible to request expansion of the emergency use authorization and EU conditional marketing authorization for BNT162b2. 

All participants in the trial will continue to be monitored for long-term protection and safety for two- years after their second dose, Pfizer noted. 

“We share the urgency to expand the authorization of our vaccine to use in younger populations and are encouraged by the clinical trial data from adolescents between the ages of 12 and 15,” said Albert Bourla, chairman and chief executive officer at Pfizer. 

“We plan to submit these data to FDA as a proposed amendment to our Emergency Use Authorization in the coming weeks and to other regulators around the world, with the hope of starting to vaccinate this age group before the start of the next school year,” Bourla continued.

Since FDA issued the first emergency use authorization for BNT162b2 in mid-December, the vaccine has proven extremely successful in various studies and trials. 

For example, at the end of January, an in-vitro study found that BNT162b2 elicited antibodies that neutralize the SARS-CoV-2 UK strain, known as B.1.1.7 lineage. Researchers found that sera in participants from a German Phase 1/2 trial contained a neutralization range that was biologically equivalent to the Wuhan SARS-CoV-2 spike.

The neutralization of the pseudovirus bearing the UK strain spike by BNT162b2 means that COVID-19 caused by the UK virus variant can also be prevented by immunization with BNT162b2. 

And most recently, the Israel Ministry of Health (MoH), Pfizer, and BioNTech shared real-world evidence showing that BNT162b2 elicited lower incidence rates of COVID-19 in individuals who were fully vaccinated. 

Researchers found that vaccine effectiveness was at least 97 percent in preventing symptomatic disease, severe or critical disease, and death. The analysis also found vaccine effectiveness of 94 percent against asymptomatic SARS-CoV-2 infections.