Pfizer stock toppled Friday after the pharma giant reported mixed results for its BioNTech-partnered combination flu and Covid vaccine.
The new shot outperformed existing vaccines protecting against influenza A and antibody responses to Covid strains were in line with current shots. But participants in the final-phase study generated a lower number of antibodies capable of handling influenza B strains.
Now, Pfizer and BioNTech say they might need to adjust the vaccine. The companies are discussing their next steps with health authorities.
On today's stock market, Pfizer stock dropped 1.4% to 28.30. BioNTech stock also fell 2.4% to 85.19.
Pfizer Stock Undercuts 200-Day Line
The study involved more than 8,000 adults between the ages of 18 and 64. Some people received the combination vaccine, while others received an existing flu shot and the Pfizer/BioNTech Covid shot, Comirnaty, in the same visit.
The combination shot elicited "robust influenza A responses," but fell flat when it came to influenza B. Pfizer and BioNTech noted there were no safety signals in participants given the combo vaccine.
Separately, Pfizer said its second-generation trivalent flu shot generated "robust" results in people ages 18 to 64. A trivalent vaccine can handle three different influenza viruses. The test in participants ages 65 and older is still ongoing. The first-generation vaccine missed its mark in that age group.
Pfizer stock undercut its 200-day moving average on Friday, according to MarketSurge. Shares are now 6% below a 29.73 buy point out of a flat base. Savvy investors are encouraged to cut their losses when a stock drops 7% to 8% below an entry.
Follow Allison Gatlin on X, the platform formerly known as Twitter, at @IBD_AGatlin.