FDA releases data on Moderna’s COVID vaccine: It looks good

[Karlston]

FDA releases data on Moderna’s COVID vaccine: It looks good

Data drop comes ahead of a potential Emergency Use Authorization on Thursday.

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As the first doses of the Pfizer/BioNTech vaccine were administered yesterday, most of the US public began a potentially long waiting game, as the vaccine will be in short supply for many months and is being administered to healthcare workers and the elderly first. For most of the US, that means waiting until manufacturing can catch up with our needs.

 

One thing that could significantly speed vaccinations is the approval of additional vaccines, and here the news is also good: today, the Food and Drug Administration released detailed data on Moderna's RNA-based vaccine, finding it well over 90 percent effective. These numbers make it highly likely that the FDA will issue an Emergency Use Authorization when it considers the issue on Thursday.

Looking good

The previous data on the vaccine's efficacy had been delivered by press release in mid-November. The FDA's documentation is, as you'd expect, far more detailed. We'll provide a summary of it here and will update the story as we get a chance to look through all 54 pages the FDA has released.

 

Like the Pfizer/BioNTech vaccine, Moderna's mRNA-1273 vaccine uses a specially packaged RNA molecule to induce human cells to produce a coronavirus protein, which the immune system will identify as foreign and attack. While many of the techniques involved have been heavily tested in other contexts, this is the first time they've been used in human vaccines, making safety and efficacy trials unusually important. Moderna had enrolled over 30,000 participants in its placebo-controlled trial. The initial analysis uses data from November 7, by which point nearly 28,000 of the participants had gone a median of seven weeks after their second vaccine dose.

 

At that date, there were five cases of SARS-CoV-2 infections in the vaccine group, compared to 90 in the placebo group, leading to a vaccine efficacy of 94.5 percent. There were no significant differences in efficacy when the data was broken down based on age, gender, or ethnicity. By November 21, with more cases, the efficacy remained at 94.1 percent, a statistically indistinguishable difference. That comes from 11 infections in the vaccine group compared to 185 among those who received a placebo. While the raw numbers suggest mRNA-1273 is slightly more effective in younger people (95.6 percent for those under 65 vs. 86.4 percent for those over), the confidence intervals for these numbers overlapped, meaning that the difference may not be statistically significant.

 

The trial also had a pre-defined "severe" category of COVID-19. By November 7, there were 19 cases in the placebo group and none in those who received the vaccine. As of November 21, it had gone to 30 cases among the placebo group, but the mRNA-1273 group remained without any cases. It's unclear whether this was because the vaccine also limits the severity of infection or because there were so few cases in the vaccinated group that the odds of having a severe case were low.

One good, two better

There's some indication that just one dose of the vaccine is helpful. At the time of the second injection, participants were tested for SARS-CoV-2; 38 in the placebo group had picked up an infection, compared to 14 in the mRNA-1273 group. The difference between placebo and vaccine groups also became significant by 14 days after the first vaccination—two weeks before the booster is normally administered.

 

Side effects were typical for vaccines: the immune response tended to produce some flu-like symptoms, like fatigue, headache, and muscle and joint pain. Problems were more common after the second dose. There were also reports of pain at the injection site and swelling and tenderness of that arm. Severe health events like heart or kidney problems occurred in both groups at roughly equal levels. The one exception was Bell's palsy, a temporary paralysis of facial muscles, which occurred in three people in the vaccine group, but only one in the placebo group.

 

Overall, these results look extremely promising, and similar efficacy was enough to gain an Emergency Use Authorization for the Pfizer/BioNTech vaccine. Having a second vaccine, and the added manufacturing capacity that comes with it, could greatly increase the speed at which public health authorities are able to move through their priority list.

 

 

FDA releases data on Moderna’s COVID vaccine: It looks good