Novavax stock fell about 9% and Moderna stock dropped 5% on Tuesday after a World Health Organization spokesperson told reporters the risk of a plague epidemic was low, following the death of a 28-year-old woman who worked at a Russian anti-plague laboratory. The declines reversed Monday's gains, when Novavax rose 20% and Moderna added 7% on outbreak concerns; BioNTech and Pfizer were little changed. The worker at the Irkutsk Anti-Plague Institute of Siberia and the Far East died last week of pneumonia of undetermined origin, and the WHO is investigating whether pneumonic plague, caused by the bacteria Yersinia pestis, was responsible. WHO spokesperson Christian Lindmeier said the institute studies dangerous pathogens, including plague, in a part of Siberia where plague occurs naturally in wild animals, and that contacts of the worker have been identified and tested with no plague or dangerous pathogens detected and none showing symptoms to date. Lindmeier said the WHO estimates the risk to be moderate to low for Irkutsk, low for the Russian Federation as a whole and very low for the WHO European region, while US Secretary of State Marco Rubio called on Russia to share more information, saying Washington is watching the situation closely hour by hour.
Moderna IncModerna shares fell 5% as WHO's low plague-risk assessment reversed outbreak-driven vaccine demand hopes.
Novavax IncNovavax dropped about 9% after WHO called plague risk low, unwinding Monday's outbreak-concern gains.
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Pfizer Inc
