CHICAGO 鈥 New data from Moderna Inc.鈥檚 large听coronavirus disease 2019 (COVID-19)听vaccine trial shows that the protection it offers wanes over time, supporting the case for booster doses, the company said in a news release on Wednesday.听听
鈥淭his is only one estimate, but we do believe this means as you look toward the fall and winter, at minimum we expect the estimated impact of waning immunity would be 600,000 additional cases of COVID-19,鈥 Moderna President Stephen Hoge said on a conference call with investors.听听
Mr.听Hoge did not project how many of the cases would be severe, but said some would require hospitalization.听听
The data stands in stark contrast with data from several recent studies that suggested Moderna鈥檚 vaccine protection lasts longer than a similar shot from Pfizer Inc.听and German partner BioNTech SE.听听
Experts said the difference is likely due to Moderna鈥檚 higher dose of messenger RNA (mRNA) and the slightly longer interval between the first and second shots.听听
Both vaccines proved to be exceedingly effective at preventing illness in their large Phase III studies.听听
Wednesday鈥檚 analysis, however, showed higher rates of infection among people vaccinated roughly 13 months ago compared with those vaccinated roughly eight months ago. The study period was from July鈥揂ugust, when Delta was the predominant strain. It has yet to undergo peer review.听听
Moderna on Sept. 1 submitted its application to the US Food and Drug Administration seeking authorization for a booster shot.听听
Mr.听Hoge said data from its booster studies shows the vaccine could increase neutralizing antibodies to levels even higher than were seen after the second dose.听听
鈥淲e believe this will reduce COVID-19 cases,鈥 he said. 鈥淲e also believe that a third dose of mRNA-1273 has a chance of significantly extending immunity throughout much of next year as we attempt to end the pandemic.鈥澨听
Briefing documents from the FDA鈥檚 analysis of Pfizer鈥檚 booster application, released earlier on Wednesday, suggest that a key issue the agency will consider is whether vaccine protection is waning.听听
In its analysis, Moderna compared the vaccine鈥檚 performance in more than 14,000 volunteers vaccinated between July and October of 2020 with some 11,000 volunteers originally in the placebo group who were offered the shot between December 2020 and March 2022 following its U.S. emergency use authorization.听听
In the two-month period from July鈥揂ugust, researchers identified 88 COVID-19 cases among those who got the two shots more recently, compared with 162 cases among those vaccinated last year. Overall, only 19 cases were considered severe, a key benchmark in assessing waning protection.听听
Moderna said there was a trend toward a lower rate of severe cases among the more recently vaccinated, although the finding was not statistically significant.听听
Data from a separate study presented on Wednesday conducted with Kaiser Permanente Southern California health system, meanwhile, shows that Moderna鈥檚 vaccine continued to perform well against the Delta variant.听听
Researchers compared data on more than 352,000 people who got two doses of the Moderna vaccine with the same number of unvaccinated individuals and found the Moderna vaccine was 87% effective at preventing a COVID-19 diagnosis, and 96% effective at preventing hospitalization.听听
Hoge said the vaccine鈥檚 initial performance is strong, but argued that protection shouldn鈥檛 be allowed to wane.听听
鈥淭he first six months are great, but you can鈥檛 count on that being stable out to a year and beyond,鈥 he said. 鈥斕Julie听Steenhuysen/Reuters听
