Login
In a dramatic blow to Moderna, the Centers for Disease Control and Prevention (CDC) has left the company’s newly approved mRNA flu vaccine off its list of options for the upcoming flu season.
The snub comes barely a month after the U.S. Food and Drug Administration (FDA) licensed mFLUSIVA for adults aged 50 and older, and weeks after MD Reports first exposed a statistically significant safety signal in its pivotal trial.
Instead of issuing new influenza vaccine recommendations for 2026–27, the CDC has fallen back on last year’s guidance.
Following repeated, unanswered inquiries from MD Reports about its next steps, the agency quietly updated its official website this month, stating that “because of legal uncertainties and inquiries,” last July’s recommendations would remain in effect for the upcoming influenza season.
The CDC has not retreated from flu vaccination. It still recommends an annual influenza vaccine for everyone aged six months and older, with rare exceptions.
For people under 65, it states there is no preference among three vaccine types — inactivated, recombinant or live attenuated influenza vaccines.
For those aged 65 and older, it preferentially recommends Fluzone High-Dose, Flublok Recombinant or Fluad Adjuvanted — and if none is available, another age-appropriate influenza vaccine should be given.
Moderna’s mFLUSIVA vaccine is conspicuously absent.
That omission does not appear to strip the product of its Vaccine Act liability protections. The government’s website, updated last month, says the Vaccine Injury Compensation Program covers “all seasonal influenza vaccines.”
Even so, the setback is significant for Moderna.
mFLUSIVA was the flagship expansion of its platform into seasonal influenza. It now enters the market without a product-specific CDC recommendation, amid mounting political and regulatory scrutiny of mRNA technology.
The vaccine’s FDA approval was mired in controversy last month after MD Reports revealed a statistically significant excess of serious adverse events in Moderna’s pivotal Phase III trial, compared with the conventional flu-vaccine arm at six months.
The FDA nevertheless described these serious adverse events as “balanced,” accepting Moderna’s pooled analysis of four disparate Phase III trials, which diluted the statistically significant imbalance seen in the pivotal study.
The stakes extend well beyond Moderna. Other manufacturers have invested heavily in mRNA influenza vaccines that could ultimately face the same roadblock at the CDC.
On Sept. 1, GSK announced it was advancing its own mRNA seasonal flu candidate into a Phase III efficacy trial after receiving FDA’s Fast Track designation in July.
Pfizer’s first-generation candidate was a flop in older adults, but the company has not abandoned the technology, launching a Phase II trial in February to test six experimental mRNA influenza vaccines against licensed flu shots.
How the CDC handles mFLUSIVA could set a precedent for the entire pipeline behind it.
This marks one of the first major decisions by new CDC Director Erica Schwartz since being sworn in by U.S. Health Secretary Robert F. Kennedy Jr. earlier this month.
Schwartz immediately faced a difficult question — would she step around the CDC’s vaccine advisory committee, ACIP and issue a recommendation for mFLUSIVA herself?
The committee has been unable to act since a federal court froze the appointments of 13 members in March.
Her decision to leave the existing recommendations in place provides the clearest answer yet that CDC’s new leadership is not stepping around ACIP.
Until ACIP returns, new vaccine recommendations appear to be on hold.
Originally published on Maryanne Demasi’s MD Reports Substack page.
