FDA Panel Recommends Moderna’s COVID-19 Vaccine for Emergency Use Authorization

The USFDA advisory panel that gave a green signal to Pfizer’s COVID-19 vaccine just a week back decided that Moderna’s coronavirus vaccine is more beneficial than risky. The panel voted 20 to 0, with one member abstaining, in favor of emergency authorization for people aged 18 years and older.

This isn’t the approval for emergency authorization, though. The emergency authorization will be granted only after the FDA accepts the nonbinding recommendation made by the advisory panel. If the FDA accepts the recommendation, it will mark a pivotal moment in the fight against the pandemic, which has infected hundreds of millions of people and killed roughly 290,000 people in the US in less than a year.

Similar to the emergency authorized Pfizer vaccine, Moderna’s vaccine is an mRNA-based vaccine that uses the genetic material of the virus to trigger the immune response. Late-stage clinical trial data show that the vaccine is 94.1% effective in the younger population (18-65 years) and 86.4% effective in the older population (>65) and people with comorbidities with two doses taken 28 days apart. For people 65 and older, the estimate is lower than that of Pfizer’s, which showed 94.1% efficacy in this population. But the apparent difference was because of the low enrollment of participants from this age group. Moreover, 86.4% of efficacy is still very high.

Moderna’s vaccine was also 100% effective in fending severe COVID-19 infections with two doses of the vaccine, which is huge compared to Pfizer’s less compelling efficacy. In the Moderna trial, 30 of 30 patients who developed severe COVID-19 infection were found in the placebo and none in the vaccine group. This is a big number to evaluate the efficacy of the vaccine in severe cases. On the other hand, Pfizer had just 10 severe cases, 9 in the placebo group and 1 in the vaccine group. These numbers are too small to gauge the vaccine’s ability to prevent serious illness.

Overall, the vaccine shows a good safety profile and the most commonly reported systemic events were fatigue, headache, muscle pain, joint pain, and chills. However, during the trial, which included 30,000 people, three vaccinated participants and one in the placebo group developed a form of temporary facial paralysis called Bell’s palsy. After deep analysis, no connection between the occurrence of Bell’s palsy and the vaccine was found. The frequency of the occurrence of the disorder was found similar to background rates found in the population. Nevertheless, caution will be taken, and people who will take the vaccine eventually will be followed for cases of Bell’s palsy.

A vaccine that stops all infections will better help control the spread of the virus. Moderna looked into asymptomatic infections and showed that its vaccine might reduce the number of asymptomatic infections. This is a plus for Moderna’s vaccine compared to Pfizer’s, for which it is still unclear if it works for asymptomatic infections.

Moderna has another advantage, which is important for the distribution of the vaccine. It can be stored in a normal refrigerator and doesn’t require ultra-low temperatures for storage like Pfizer’s vaccine. Unopened Moderna’s vaccine vials can be stored in a refrigerated fridge between 2 to 8ºC for up to 30 days and, once opened, should be stored for no more than 6 hours at 8 to 25ºC.

After observing severe anaphylaxis reactions in two individuals in the UK and two in the US who received Pfizer’s vaccine, the FDA was concerned how Moderna’s vaccine would fare, which is almost similar to Pfizer’s mRNA vaccine. However, Moderna quickly looked into their trial data to see if there was any indication of anaphylaxis in their trial participants and observed that there was just one case, which triggered two months after being vaccinated and hence appeared unlikely to be vaccine-related. Moreover, Tal Zaks, Moderna’s Chief Medical Officer, noted that Moderna’s vaccine uses lipid nanoparticles, which are different from Pfizer’s. Hence, it will not necessarily trigger the same immune reaction as Pfizer’s.

Nevertheless, the FDA is working with Moderna to add any relevant information related to allergic reactions in the prescription to keep the people informed.

The Federal officials at the Centers for Disease Control and Prevention are prepared to distribute the vaccine within 24 hours of EUA. Moderna plans to have 5.9 million doses ready for the US in its first rollout round in late December. This will be enough for 3 million people in the country. However, it is expected that 20 million doses of Moderna can be delivered by the end of the month, securing additional 10 million people in the country from the virus. The 10 million who would get the vaccine will initially include elderly Americans and those on the front line, including healthcare workers.

By Ruchi Jhonsa, Ph.D.

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Ruchi Jhonsa