Pfizer’s combined COVID and flu vaccine is advancing to the final-stage trial following encouraging results.

Pfizer announced that its combined COVID and flu vaccine candidates have exhibited positive initial results in an early to mid-stage study. Consequently, they are moving forward to the final-stage trial, bringing them closer to potential regulatory approval for a combined COVID and flu shot. Pfizer had previously expressed its intention to introduce a vaccine targeting both respiratory viruses in 2024 or later.

Various vaccine manufacturers, including Pfizer, Moderna, and Novavax, believe that combination vaccines can streamline the process of safeguarding against respiratory viruses that tend to peak simultaneously in certain seasons.

Annaliesa Anderson, Pfizer’s Head of Vaccine Research and Development, noted that this vaccine has the potential to mitigate the impact of two respiratory diseases with a single injection, simplifying immunization practices.

Pfizer’s CEO, Albert Bourla, believes that combination vaccines will enhance vaccination rates by offering convenience. It is worth noting that COVID vaccine uptake in the United States was low last year and may face similar challenges this year.

The trial assessed the safety, tolerability, and efficacy of Pfizer’s combined vaccine candidates in adults aged 18 to 64. The study also compared these combination vaccines to a licensed influenza vaccine and Pfizer’s bivalent COVID shot, which targets omicron variants BA.4 and BA.5, along with the original strain of the virus.

The results demonstrated robust immune responses to influenza A, influenza B, and COVID strains for Pfizer’s combination vaccine “lead” formulations, with safety profiles consistent with the company’s COVID vaccine.

Pfizer and BioNTech are also developing a vaccine targeting both COVID and RSV, while Moderna and Novavax are working on their own combination shots.