BETHESDA, Md. — As the world turns the page on 2020, millions continue to wait for word of how the first patients to receive the coronavirus vaccine respond to treatment. Now, a new study is confirming that the COVID vaccine from biotech company Moderna is not only effective after both shots, but also free of serious side-effects.
Researchers from the National Institutes of Health find the new vaccine by Moderna, mRNA-1273, is over 94 percent effective at preventing symptomatic cases of COVID-19. The results come from a clinical phase 3 trial which began in late July and involved over 30,000 adult volunteers.
Starting on July 27, participants received either two 100-microgram (mcg) doses of the potential vaccine or two shots of a placebo 28 days apart. The volunteers had an average age of 51, with a quarter of the group over the age of 65. Another 17 percent were under 65 years-old but also had medical conditions putting them at high-risk for COVID-19.
Impressive results after both Moderna COVID-19 vaccine shots
Researchers report that, as of Nov. 25, 2020, only 196 patients were diagnosed with a symptomatic case of COVID-19. These cases developed at least 14 days after the patients received their second shot. Of these 196 patients, 185 came from the group who received the placebo shot.
Only eleven patients who received mRNA-1273 in the trial developed COVID-19 after their second shot. None of these cases were diagnosed as a severe infection. These results reveal COVID cases are 94.1 percent lower in patients received the Moderna vaccine verses a placebo shot.
Even more encouraging, the new vaccination also has a high rate of success after just one dose. Only 236 patients in the trial developed COVID-19 at least 14 days after taking the first dose. Of this group, 225 come from the placebo volunteers. Again, only 11 volunteers taking the Moderna vaccine developed a symptomatic case of coronavirus; giving the vaccine a 95.2 percent rate of success after just one dose.
No concerns over side-effects
Study authors say the trial reveals no major concerns when it comes to side-effects from taking Moderna’s COVID-19 vaccine. In about half of the volunteers taking mRNA-1273, patients reported issues including fatigue, muscle aches, joint pain, and headaches after their second shot. Although researchers say these side-effects could be moderate to severe, they only tended to last two days.
Investigators also note none of the volunteers experienced vaccine-associated enhanced respiratory disease (VAERD). This condition is a rare complication discovered in patients taking the whole-inactivated respiratory syncytial virus (RSV) vaccine in the 1960’s. It occurs when a vaccine triggers an immune response that isn’t powerful enough to actually stop an infection.
The one issue researchers are still studying is whether the Moderna COVID vaccine can stop the transmission of COVID-19 from patients who already have the virus. The initial results show mRNA-1273 can provide some level of protection for asymptomatic patients who could infect others.
“This process demonstrates what is possible in the context of motivated collaboration among key sectors of society including academia, government, industry, regulators and the larger community,” study authors write in a media release.
The study appears in the New England Journal of Medicine.