The European Medicines Agency on Thursday warned of severe allergic reactions as a potential rare side effect of Novavax’s coronavirus vaccine.
A risk assessment of the vaccine, sold as Nuvaxovid in Europe since December, said there were “a few cases” of anaphylaxis, or severe allergic reactions.
The Maryland-based drugmaker said the warning was not initially listed on the vaccine’s label because there were no severe allergic reactions observed in clinical testing. The company has so far received two reports of reactions that met certain criteria after rollout of the vaccine. In the EU, approximately 250,000 doses have been administered to date.
“Because anaphylaxis can occur with all vaccines and based on these cases, Novavax and the EMA agreed to update the label accordingly,” the company said.
The warning comes a day after the Food and Drug Administration cleared the vaccine for emergency use, making it the fourth shot available in the U.S. that can prevent COVID-19. The FDA similarly warns healthcare professionals to monitor for rare, acute allergic reactions after administration of all four vaccines. Still, safety questions could undercut the appeal of Novavax’s vaccine to the roughly 10% of U.S. adults who have not received a vaccine dose and are eligible for the shot.
Novavax’s vaccine uses an older technology widely used in other vaccines, a feature that health officials believe could attract adults who are hesitant about the messenger RNA approach used by Moderna as well as Pfizer and BioNTech.
The EMA also cautioned of side effects for Nuvaxovid such as unusual feeling in the skin, like tingling, or decreased feeling in the skin. The regulator is additionally monitoring whether myocarditis and pericarditis are associated with the shot. The agency noted that Australia recently added pericarditis, or inflammation of the heart lining, as a side effect.
The FDA has warnings for myocarditis for all four vaccines authorized for use in the U.S. Myocarditis is a complication of COVID-19 as well.
Shares in Novavax fell by more than 26% on Thursday and traded down by more than 7% at its lows in Friday morning trading.