Moderna Vaccine 94% Effective, Confirms New England Journal of Medicine

RIO DE JANEIRO, BRAZIL – The vaccine against Covid-19 developed by Moderna in partnership with NIH has an overall efficacy of 94.1%, according to a study published on Wednesday, December 30th, in the New England Journal of Medicine. The preliminary data analysis of phase 3 trial found that the immunizer is able to protect against severe cases of the disease.

The efficacy results are based on the data analysis of 30,420 volunteers in the United States. Of these, 15,210 were administered the vaccine and the other half a placebo. The vaccine was administered in two doses, in a 28-day interval.

Efficacy was determined by the number of Covid-19 cases recorded among volunteers 14 days after the second dose was administered. In the period analyzed, 196 Covid-19 cases were confirmed among participants: 11 among those who were administered the vaccine and 185 among volunteers taking the placebo. Of the 30 severe cases of the disease, one resulted in death. All of these cases occurred within the placebo group.

The vaccine was considered safe, with transient side effects. The rate of severe adverse events was low and similar in both the vaccine and placebo groups. These data had been disclosed by the pharmaceutical company a few weeks ago, but have only now been published in a scientific journal and peer reviewed.

This is the third time that a laboratory has published data concerning the results of phase 3 trials of a vaccine against Covid-19 in a scientific journal. Early this month, data on the Oxford-AstraZeneca phase 3 vaccine trials were published in The Lancet; afterwards, data on the Pfizer-BioNTech’s immunizer appeared in the New England Journal.

Moderna was the first company to begin clinical trials of a vaccine against Covid-19 in humans in March. This swiftness was only possible because, in addition to remarkable efforts, the researchers had experience with the development of vaccines for both SARS and MERS – also caused by coronavirus species, but more lethal and less contagious – during their respective epidemics in 2003 and 2012; however, their products never reached the market due to a peculiar mismatch. By the time they were ready, the outbreaks had already been contained and the investment needed to continue the work was suspended.

At a time when the world is facing a new explosion in the number of Covid-19 cases, vaccines are more needed than ever. The emergency use of the Moderna vaccine was approved in the United States on December 18th and has already begun to be administered to the population. There is still no scheduled date for the beginning of vaccination in Brazil, according to Moderna, although the vaccine is among the options of the Covax Facility agreement, of which Brazil is a signatory.

On Wednesday, December 30th, Brazil registered a one-week rolling average of 36,240 new cases and 665 deaths by Covid-19 per day.