Novavax, Inc. (Nasdaq: NVAX), a biotechnology company developing next-generation vaccines for serious infectious diseases, today announced data from a preclinical study of the company’s combination quadrivalent seasonal flu vaccine (NanoFlu™) and COVID-19 vaccine candidate (NVX-CoV2373). The NanoFlu/NVX-CoV2373 combination vaccine demonstrated positive immune responses to both influenza and SARS-CoV-2. A pre-print of the manuscript is available at bioRxiv.org.
The manuscript, titled ‘Combination Respiratory Vaccine Containing Recombinant SARS-CoV-2 Spike and Quadrivalent Seasonal Influenza Hemagglutinin Nanoparticles with Matrix-M™ Adjuvant,’ studied a combination vaccine comprising a quadrivalent nanoparticle influenza vaccine formulated together with a recombinant SARS-CoV-2 spike protein vaccine and Matrix-M™ adjuvant. The combination vaccine-elicited robust responses to both influenza A and B and protected against the SARS-CoV-2 virus. Clinical studies of the combination vaccine are expected to begin by the end of the year.
“Despite low rates during the COVID-19 pandemic, influenza remains a significant risk to global public health and the need for versatile, more effective vaccines is as important as ever, including against the flu. This study’s results build on our success to date with NVX-CoV2373, and with NanoFlu, which successfully achieved all of its objectives in a pivotal Phase 3 trial announced last year,” said Gregory M. Glenn, M.D., President of Research and Development, Novavax. “We believe that this novel combination vaccine candidate, which leverages Novavax’ technology platform and Matrix-M™ adjuvant, could be an important future tool in the long-term fight against both of these harmful respiratory viruses.”
The preclinical study found that the combination NanoFlu/NVX-CoV2373 (qNIV/CoV2373) vaccine-induced functional influenza and COVID antibodies in ferrets. Hemagglutination inhibition (HAI) and ACE2 receptor-inhibiting titers were comparable between immunization with the combination vaccine and with its respective component vaccines. Antibody titers were elevated two weeks after a single dose and increased even further two weeks following a second immunization.
Hamsters that received the combination NanoFlu/NVX-CoV2373 vaccine had elevated levels of SARS-CoV-2 anti-S IgG two weeks after the first immunization, which increased significantly after a second dose, with levels comparable to animals that received the NVX-CoV2373 vaccine alone. Human ACE2 receptor inhibiting antibody levels responded similarly. The immune responses to influenza A and B strains elicited by NanoFlu/NVX-CoV2373 were comparable to immunization with NanoFlu alone. Further, the combination vaccine-induced antibodies against SARS-CoV-2 neutralizing epitopes, including at hidden or cryptic sites, that are common between USA-WA1 and the B.1.351 variant.
Protection after SARS-CoV-2 challenge
When hamsters were challenged with SARS-CoV-2, animals immunized with NanoFlu/NVX-CoV2373 retained their body weight comparably to non-infected animals and those immunized with NVX-CoV2373 alone. An examination of viral load in the upper and lower respiratory tract showed that little or no virus was detected four days after COVID-19 infection in animals immunized with NanoFlu/NVX-CoV2373 or with just NVX-CoV2373. Microscopic and macroscopic observations of the lungs showed no remarkable findings in animals immunized with either the combination vaccine or with NVX-CoV2373 alone.
“Seasonal influenza and COVID-19 combination vaccines will likely be critical to combating emerging COVID-19 variants,” said Russell ‘Rip’ Wilson, Executive Vice President and NanoFlu General Manager, Novavax. “Millions of people are affected by influenza each year in the U.S., and despite our vaccination efforts, currently available flu vaccines are only partially effective. Our NanoFlu vaccine Phase 3 clinical trial achieved all of its primary endpoints, and we expect this combination vaccine will help control both COVID-19 and influenza illness.”