Vaccine stocks retreat after WHO calls plague risk 'low'
Novavax was off 13% on Tuesday as of this writing / Photo: Cristian Storto / Shutterstock.com
Vaccine makers’ shares plunged in New York trading on Tuesday, the selloff triggered by the World Health Organization’s assessment that the risk of a plague epidemic was “low,” as Yahoo Finance reports.
As of this writing, Novavax shares had fallen more than 13%. Moderna dropped almost 8%, BioNTech gave up 2.4%, and Pfizer declined less than 1%. Shares of small biotech Arcturus Therapeutics, which develops messenger RNA-based drugs, plunged 11%, while vaccine maker Emergent BioSolutions was off 7%.
Context
In the early hours of Friday, a 28-year-old employee of an plague research institute in Russia died. The official cause of death was given as “pneumonia of undetermined origin.” Russian authorities stated that testing of samples taken from the deceased found no “microorganisms linked to her work” and that none of her contacts had been diagnosed with an infectious disease. Local media reported that around 200 people had previously been placed under quarantine, Reuters reports.
The incident prompted international concern, including in Washington. U.S. President Trump offered Russia assistance, while Secretary of State Marco Rubio said it was incumbent on Moscow to share more information.
At a Tuesday briefing, the WHO said Russia had informed it that no cases of plague had been recorded in Irkutsk, the city where the institute is located, Reuters writes. Based on preliminary information, the international organization assessed the risk as “moderate to low for Irkutsk, a low risk for the Russian Federation as a whole and very low for the WHO European region.”
According to the WHO, 3,847 suspected human cases of plague and 423 deaths were recorded in 10 countries from 2019 through 2025. Most occurred in the Democratic Republic of the Congo and Madagascar. However, cases also occur occasionally in wealthier countries. The U.S. typically records several infections a year, mostly in western states where the bacteria circulate naturally among wild rodents and their fleas, Bloomberg reports.
