Vaccine stocks Moderna and BioNTech toppled Wednesday after an Israeli study suggested immunity wanes quickly following a second Covid booster shot.
Researchers examined data from more than 1.25 million people age 60 and older who were eligible for a fourth messenger RNA dose from Jan. 10 to March 2. They found rates of Covid infection and severe disease were lower after the fourth dose of Pfizer's BioNTech-partnered shot.
But "protection against confirmed infection appeared short-lived, whereas protection against severe illness did not wane during the study period," researchers said in a report published by the New England Journal of Medicine.
On today's stock market, both vaccine stocks dropped. Moderna stock tumbled 4.6% to 154.62. BioNTech stock lost 7.8% and closed at 166.65. Shares of Pfizer, on the other hand, rose 3.2% to 52.87.
Vaccine Stocks: Four Shots Tested
The study from Israel found the lowest number of Covid infections — severe and mild — among those who received four doses of the Pfizer-BioNTech vaccine.
Researchers noted there were 1.5 severe cases and 177 cases total per 100,000 people who received four doses of the mRNA shot. In the three-dose group, there were 3.9 severe cases and 361 total cases. Among those who received two shots only, the rates were 4.2 and 388, respectively.
"Protection against severe illness did not wane during the six weeks after receipt of the fourth dose," the researchers said.
But eight weeks after the fourth dose, infection rates were similar between the four-dose group and those who received three and two mRNA shots. The bearish point led vaccine stocks to tumble.
Moderna Falls Below 50-Day Line
The news comes shortly after the Food and Drug Administration signed off on fourth Covid booster shots for people age 50 and older. On Wednesday, an FDA panel met to discuss the criteria it would use to update its booster strategy as Covid becomes an endemic disease, similar to the flu.
Vaccine stock Moderna fell below its 50-day line on Wednesday, according to MarketSmith.com. At the same time, BioNTech shares remained narrowly above theirs.
Follow Allison Gatlin on Twitter at @IBD_AGatlin.
