Moderna Plunges as mRNA-based Flu Vaccine Fails to Ace Existing Shots

By Reuters Staff

December 13, 2021

(Reuters) - Moderna Inc shares tumbled 11% after early data showed that the company's mRNA-based flu vaccine might not be strong enough to give it an edge over already approved flu vaccines in the market, especially for older people.

The Cambridge, Massachusetts-based vaccine maker said in an investor presentation that antibody levels of its vaccine against four seasonal strains of influenza A and B in an early stage study were not as robust in older adults as Sanofi's Fluzone HD.

"On one hand, the antibodies increased to good levels, but on the other hand, the levels aren't necessarily seen as high or necessarily better than some high-efficacy vaccines such as Flublok or Fluzone HD," Jefferies analyst Michael Yee said in a client note.

The vaccine candidate, mRNA-1010, is based on the messenger RNA technology that also underpins the company's COVID-19 shots.

Following the huge success of mRNA-based vaccines in fighting the COVID-19 pandemic globally, drugmakers are rushing to tap the technology and develop shots for other diseases, including influenza.

The early-stage study, testing the vaccine in 180 subjects, is ongoing and a mid-stage study testing it against an already approved flu vaccine is fully enrolled with 500 participants, the company said in a press release, adding that the interim analysis is expected in early 2022.

This data, though limited, puts Moderna ahead of other drugmakers, including rival Pfizer Inc, which is also testing a flu vaccine based on messenger RNA.

Moderna also said it was developing a pan-respiratory annual booster vaccine, which would target multiple viruses including COVID-19, flu and Respiratory syncytial virus.

The new vaccine, mRNA-1345, has demonstrated positive early stage results, it said.

Vaccine developer Novavax is also testing a combined flu and COVID-19 vaccine, based on protein subunits, which has shown promise in preclinical studies.

processing....