Vaccine maker Moderna believes people who received two doses of its COVID-19 vaccine will need a third dose before winter as a booster shot.
The company said Thursday it is also working on a single shot that would provide an annual booster for COVID-19, as well as flu and the respiratory condition RSV.
“We believe that increased force of infection resulting from Delta, non-pharmaceutical intervention (NPI) fatigue, and seasonal effects (moving indoors) will lead to an increase of breakthrough infections in vaccinated individuals,” the company said in an investor presentation posted to its website.
Moderna said early-stage testing showed its booster candidate was effective against COVID variants of concern, including delta.
According to the latest CDC data, some 63.6 million Americans have been fully vaccinated using the Moderna two-dose sequence.