Moderna
Preliminary results from a clinical trial testing the company's so called "bivalent" vaccine, which targets both the original SARS-CoV-2 strain of the virus and the beta variant, showed the next-gen vaccine produces high levels of viral-neutralizing antibodies for months.
The redesigned vaccine targets nine mutations found in the beta variant, four of which are shared with the highly transmissible Omicron strain.
"We believe that these results validate our bivalent strategy," said CEO Stephane Bancel in a press release. Bancel added that another bivalent vaccine which combines the original strain with the Omicron strain is the company's lead candidate for a fall vaccination campaign ahead of the winter season for the Northern Hempisphere. Results for trials testing that vaccine are expected in the second quarter, according to Moderna.
Moderna's original COVID mRNA vaccine was developed to recognize the spike protein on the SARS-CoV-2 virus--which the virus uses to infect human cells--and block infection. However, as the virus continues to mutate, its spike protein changes, making it harder for the antibodies produced from the original vaccine to protect against new strains.
While, two doses of Moderna's original vaccine still provides strong protections against hospitalization and death, the vaccine's efficacy against infection has diminished over time as the Delta and then Omicron variants became the dominant strains spreading across the world. A third booster dose does provide protection against infection and hospitalization, but researchers believe that protection will also lessen as the virus continues to evolve.
A 50-microgram dose of Moderna's bivalent vaccine doubled virus-neutralizing antibodies against Omicron six months after injection compared the same dosage of the company's original vaccine, the preliminary data showed. The new shot also increased antibody levels against the Delta variant six months post infection, but those level were lower than those produced against Omicron.
The trial included 895 participants who received a single booster dose (either 50-micrograms or 100-micrograms) of the updated vaccine after their first two shot regimen of the original vaccine.
