Several COVID-19 vaccine makers got off to a rocky start this week. Shares of BioNTech (BNTX -1.45%) were sinking 8.2% as of 12:27 p.m. ET on Monday. Moderna (MRNA -1.82%) and Novavax (NVAX 2.52%) stocks were down 5.3% and 6.4%, respectively.
Often when these three vaccine stocks fall on the same day, it's because of the same story. That's not the case this time, though. There are different reasons behind each of these stocks sliding today.
Investors appear to be concerned about BioNTech because of talks stalling over Taiwan's purchase of its COVID-19 vaccine for pediatric use. The problem is that BioNTech and its partner, Chinese drugmaker Fosun, own the marketing rights to the Taiwan market. However, BioNTech's other partner, Pfizer, makes the COVID-19 vaccine for children.
Moderna's shares are slipping even though the company's COVID-19 vaccine won approval in Taiwan over the weekend for use in immunizing kids ages 6 to 11. The positive news wasn't enough to halt Moderna's downward momentum in recent weeks after it reported concerning side effects for its experimental flu vaccine.
Novavax also had good news with a Japanese Health Ministry committee approving its COVID-19 vaccine. This paves the way for a likely full approval of Novavax's vaccine in Japan. However, this only underscores investors' worries that the company still hasn't received Emergency Use Authorization (EUA) for the vaccine in the important U.S. market. Novavax requested U.S. EUA on Jan. 31.
It's quite possible that today's moves are overreactions. BioNTech's fortunes don't hinge on selling its vaccine for pediatric use in Taiwan. Moderna's lower prospects for its flu vaccine are already largely baked into its share price. Novavax's news in Japan arguably should have provided at least a small bump for the stock.
However, investors remain concerned about the overall dynamics in the COVID-19 vaccine market. No one knows how strong the demand for vaccines will be going forward.
Novavax probably has the clearest path to rebounding. If the company wins U.S. EUA for its COVID-19 vaccine, investors will be able to breathe more easily. When and if that authorization comes, though, is still up in the air.
BioNTech and Moderna have other potential catalysts. Their stocks could rise if the companies secure additional supply agreements. Successful testing of versions of their vaccines that target the coronavirus omicron variant could also cheer up investors.