The effectiveness of Moderna’s COVID-19 vaccine against infection turns negative over time, according to a new study that was funded by the vaccine maker.
The effectiveness of three doses—a primary series and a booster—against infection remained above 50 percent after 150 days against BA.1, a subvariant of the Omicron virus variant, researchers estimated.
But against more recent strains, including the currently-dominant BA.5, the effectiveness turned negative.
Against BA.2, BA.4, and BA.5, the effectiveness went negative after 150 days.
Against BA.1.12.1, the effectiveness turned negative after 91 days.
Negative effectiveness means a vaccinated person is more likely to contract COVID-19, the disease the virus causes, than an unvaccinated person….