On Wednesday, Moderna released more data on the so-called breakthrough cases it says supports the push for wide use of Covid-19 vaccine booster shots.

The drugmaker shared a new analysis from its phase three study showing that the incidence of breakthrough Covid cases occurring in fully vaccinated people, was less frequent in a group of trial participants who were more recently inoculated, suggesting immunity for earlier groups had started to wane, according to CNBC.

Out of 11,431 people vaccinated between December and March, there were 88 identified cases of breakthrough. The company announced this in a release, which stated that compared with 162 breakthrough cases out of 14,746 trial participants vaccinated in July through October of last year.

In addition to that, according to a manuscript of the results shared by the company, there were fewer severe cases of Covid-19 cases in the group that received the vaccine more recently as three Covid-19 related hospitalizations occurred in the group, resulting in two deaths.

However, there were no hospitalizations or deaths in the group that recently received the vaccine, although the finding on severe cases was not statistically significant.

In a phone interview, Moderna President Stephen Hoge said, “There’s a large debate, we all know, about whether or not vaccine boosters are going to be necessary into the fall. That debate, what makes it really hard is it’s not really about whether the vaccine worked last month. It’s really about whether it’s going to work this winter.”

The analysis presented by Moderna has not been peer-reviewed yet.

It has been earlier reported that the Food and Drug Administration vaccine advisory committee meeting would be holding in two days where a panel of outside experts will debate whether there is enough data
to support widely distributing booster shots across the U.S.

The agency’s Vaccines and Related Biological Products Advisory Committee has been scheduled to debate administering third doses of Pfizer and BioNTech’s vaccine as federal health regulators say they need more time to review Moderna’s application for extra doses.