Pfizer and BioNTech have announced positive safety, tolerability and immunogenicity data for a booster dose of their Covid-19 vaccine Comirnaty in children aged five to 11 years, from a Phase 2/3 study.
In the Phase 2/3 trial, data were analysed from 140 children aged five to 11 years, who received a booster dose of Comirnaty, six months after the second dose of the primary series.
The data showed an increase in neutralising titers against SARS-CoV-2 Omicron variant and wild-type strain compared to the two-dose primary series, regardless of prior infection.
A sub-analysis of 30 sera from the study participants showed that the third dose of Comirnaty has increased the neutralizing antibody titers by 36 folds, compared to the primary series.
The immune sera obtained from 30 participants were tested using a live SARS-CoV-2 recombinant virus fluorescent foci reduction neutralization test (FFRNT).
Also, the immunogenicity data showed an increase in neutralising geometric mean titers (GMTs) against SARS-CoV-2 wild-type strain by six folds, compared to neutralizing GMTs after the second dose.
Pfizer said that the data will strengthen the potential function of a booster dose in maintaining high levels of protection against the virus in children aged five to 11 years.
The companies are planning to seek an emergency use authorisation (EUA) from the US Food and Drug Administration (FDA), for their booster dose in this age group.
Also, the companies intend to share the data with the European Medicines Agency (EMA) and other regulatory agencies worldwide, to obtain regulatory approval for the booster dose.
Earlier this year, the US FDA expanded the EUA for a booster dose of their Covid-19 vaccine to include people aged 12 and above.
In addition, the US agency has authorised the third primary series dose for immunocompromised children aged five to 11 years, at least 28 days after the second dose.
The decision was based on the review of the real-world data from a booster dose trial in Israel, including safety data from more than 6,300 individuals, aged 12 to 15 years.