The Phase 2 trial of BNT162b5 will enrol around 200 participants, aged between 18 and 55 years, who will be administered one booster dose of a US-authorised Covid-19 vaccine at least 90 days before their first visit to the trial
Pfizer and BioNTech will study enhanced Covid-19 vaccine. (Credit: Spencer Davis from Pixabay)
Pfizer and BioNTech have commenced a Phase 2 trial to evaluate the safety, tolerability, and immune response of an enhanced, mRNA-based Covid-19 vaccine candidate.
In the randomised, active-controlled, observer-blind study, the companies will assess their bivalent Covid-19 vaccine candidate, dubbed BNT162b5, at a 30µg dose level.
The new vaccine candidate will contain RNA sequences encoding enhanced prefusion spike proteins for the wild-type SARS-CoV-2 strain and that of an Omicron variant.
Its enhanced spike protein has been modified to increase the extent of the immune response to better protect against Covid-19, said Pfizer.
The BA.4 and BA.5 subvariants are estimated to account for nearly 95% of the prevalent coronavirus variants in the US as of 23 July, reported Reuters.
Last month, the US Food and Drug Administration (FDA) urged vaccine manufacturers to target BA.4 and BA.5, the two currently dominant Omicron subvariants, for a potential fall season booster dose.
Pfizer said: “This is the first of multiple vaccine candidates with an enhanced design which the companies plan to evaluate as part of a long-term scientific Covid-19 vaccine strategy to potentially generate more robust, longer-lasting, and broader immune responses against SARS-CoV-2 infections and associated Covid-19.”
The US drugmaker said that the study of its enhanced BNT162b5 will enrol around 200 participants, aged between 18 and 55 years.
The participants will be given one booster dose of a US-authorised Covid-19 vaccine at least 90 days before their first visit to the trial.
They will be categorised as per the number of months since they received the last dose of the Covid-19 vaccine before entering the study, as three to six months or more than six months.
Pfizer-BioNTech Covid-19 Vaccine, also called BNT162b2, has been developed in partnership with BioNTech and Pfizer, leveraging BioNTech’s unique mRNA technology.
The vaccine has been approved in various countries worldwide, for various indications
Last month, Pfizer and BioNTech have signed a $3.2bn revised agreement with the US government to supply additional doses of their Covid-19 vaccine to the US.
The companies have agreed to supply 105 million doses of their Omicron-adapted Covid-19 vaccines, subject to the US Food and Drug Administration (FDA) authorisation.