Trial of COVID-Influenza Combination Vaccine Shows Safety, Produces Immunologic Response

Initial results from a phase 1/2 clinical trial of the Novavax’s COVID-influenza combination vaccine (CIC) showed it was well-tolerated and produced an immunological response, according to a Novavax press release.

The CIC is a combination of Novavax’s COVID-19 vaccine, NVX-CoV2373, and its quadrivalent influenza vaccine candidate.

"We continue to evaluate the dynamic public health landscape and believe there may be a need for recurrent boosters to fight both COVID-19 and seasonal influenza," said Gregory M. Glenn, MD, president of research and development at Novavax, in a press release. "We're encouraged by these data and the potential path forward for a combination COVID-19-influenza vaccine as well as stand-alone vaccines for influenza and COVID-19."

The trial showed that the safety and tolerability profile of the combination vaccine was consistent with the NVC-CoV2373 alone and quadrivalent nonparticle influenza vaccine reference formulations in the trial. Further, the combination vaccine was found to be well-tolerated, and serious adverse events were rare, with none assessed as being related to the vaccine.

The study used a Design of Experiments (DOE) modeling-based approach to help identify the dose selection of both the COVID-19 and influenza antigens for further development compared to traditional approaches. Various CIC vaccine formulations induced immune responses in participants comparable to reference stand-alone influenza and stand-alone COVID-19 vaccine formulations in the preliminary trial.

Data released last year from the phase 3 PREVENT-19 trial showed NVX-CoV2373 provides 100% protection against moderate and severe COVID-19 and 90.4% efficacy overall.

During the trial, investigators enrolled 29,960 people in the United States and Mexico to assess the efficacy, safety, and immunogenicity of the vaccine. Taking place across 119 sites, the study focused on including a population representative of the communities and demographic groups that have been shown to be most affected by the disease.

There were 77 cases of COVID-19 observed, with 63 in the placebo group and 14 in the vaccine group. The observed cases in the vaccine group were mild and in the placebo group there were 10 moderate cases and 4 severe cases observed, yielding a vaccine efficacy of 100% (95% CI: 87, 100) against moderate or severe disease.

Novavax's quadrivalent recombinant hemagglutinin (HA) protein nanoparticle influenza vaccine uses HA amino acid protein sequences similar to the recommended wild-type circulating virus HA sequences.

A phase 2 confirmation trial of the combination vaccine is expected to start by the end of 2022. Novavax indicated that it is developing the combination with an eye toward boosters being needed on an annual basis.

REFERENCE

Initial Results from Novavax' COVID-19-Influenza Vaccine Trial are First to Show Feasibility of Combination Vaccine. Novavax. April 20, 2022. Accessed April 21, 2022. https://ir.novavax.com/2022-04-20-Initial-Results-from-Novavax-COVID-19-Influenza-Vaccine-Trial-are-First-to-Show-Feasibility-of-Combination-Vaccine