Pfizer, BioNTech report positive early data from clinical trial of Omicron BA.4/BA.5-Adapted Bivalent Booster in 18 years and older

A 30-µg booster dose of the Omicron BA.4/BA.5-adapted bivalent vaccine demonstrated a substantial increase in the Omicron BA.4/BA.5 neutralizing antibody response above pre-booster levels based on sera taken 7 days after administration, with similar responses seen across individuals aged 18 to 55 years of age and those older than 55 years of age (40 participants in each age group). When comparing responses in individuals older than 55 years of age who received either the bivalent vaccine, or the original vaccine, a 30-µg booster dose of the Original Pfizer-BioNTech COVID-19 Vaccine (also referred to as BNT162b2 Wild Type) elicited more limited increases in the neutralizing antibody response against the Omicron BA.4/BA.5 variants. COVID-19 vaccine responses to date have reliably shown consistent trends across age groups and are further supported by these early data on the bivalent vaccine. Together, these data suggest a 30-µg booster dose of the Omicron BA.4/BA.5-adapted bivalent vaccine is anticipated to provide better protection against the Omicron BA.4 and BA.5 variants than the original vaccine for younger and older adults. The Omicron BA.4 and BA.5-adapted bivalent vaccine was well tolerated with early data indicating a favorable safety profile, similar to that of the original vaccine.

"Since the earliest days of the pandemic, we have strived to transparently share data regarding our COVID-19 vaccines in the interest of public health," said Albert Bourla, Chairman and Chief Executive Officer, Pfizer. "While we expect more mature immune response data from the clinical trial of our Omicron BA.4/BA.5-adapted bivalent vaccine in the coming weeks, we are pleased to see encouraging responses just one week after vaccination in younger and older adults. These early data suggest that our bivalent vaccine is anticipated to provide better protection against currently circulating variants than the original vaccine and potentially help to curb future surges in cases this winter."

"These preliminary findings are consistent with our preclinical data showing a substantial increase in the neutralizing antibody response against the Omicron sublineages BA.4 and BA.5," said Prof. Ugur Sahin, M.D., CEO and Co-founder of BioNTech. "The current dominance of BA.4/BA.5 and related sublineages, underscores the importance of our data and science-based approach to develop a vaccine which is adapted to these prevalent strains of the virus and make it available in a timely manner."

Immunogenicity was evaluated using a SARS-CoV-2 live virus fluorescent focus reduction neutralization test (FFRNT) assay. Sera were collected 7 days post second booster dose from participants aged older than 55 (40 participants in each age group) and compared to 7-day post sera from 40 participants older than 55 years of age that had received three prior doses of BNT162b2 encoding the wild-type spike-protein of SARS-CoV-2 and a second booster with BNT162b2 Wild-Type. Sera were also collected at 7 days post second booster dose from participants 18 to 55 years of age who received the Omicron BA.4/BA.5-adapted bivalent booster (n=40) to compare bivalent vaccine responses in younger and older adults. The time between third and fourth doses for the bivalent vaccine recipients was approximately 11 months compared to approximately 6 months for the original vaccine. Despite this difference, baseline neutralizing antibody titers were generally similar across groups. Among the participants, samples were equally stratified at baseline in each group between those who had a prior or current history of SARS-CoV-2 and those with no prior or current history of SARS-CoV-2.

"Additional data measuring responses at one-month post-administration of the Omicron BA.4/BA.5 bivalent vaccine booster are expected in the coming weeks. These data will be used to support potential full licensure and global registration of the companies' Omicron BA.4/BA.5-adapted bivalent COVID-19 vaccine," the release stated.

Additionally, the companies have initiated a similar Phase 1/2/3 trial investigating the Omicron BA.4/BA.5-adapted bivalent vaccine among children 6 months through 11 years of age.

A 30-µg booster dose of the Omicron BA.4/BA.5-adapted bivalent vaccine has been authorized for emergency use by the U.S. Food and Drug Administration (USFDA) for ages 12 years and older and has also been granted marketing authorization in the EU by the European Medicines Agency (EMA) for the same age group.

The Pfizer-BioNTech COVID-19 Vaccines (COMIRNATY), which are based on BioNTech's proprietary mRNA technology, were developed by both BioNTech and Pfizer. BioNTech is the Marketing Authorization Holder for BNT162b2 Wild Type and BNT162b2 Bivalent (WT/OMI BA.4/BA.5) in the United States, the European Union, the United Kingdom, Canada and other countries, and the holder of emergency use authorizations or equivalents in the United States (jointly with Pfizer) and other countries. Submissions to pursue regulatory approvals in those countries where emergency use authorizations or equivalent were initially granted are planned.