4:13 PM, Feb 27, 2020


Ask Dr. Nandi: Moderna’s coronavirus vaccine shows encouraging early results in human safety trial

Posted at 5:26 PM, May 18, 2020
and last updated 2020-05-18 17:26:06-04

There’s some positive news concerning an experimental vaccine for the coronavirus. Drugmaker Moderna has announced that all of their participants in a stage 1 trial produced antibodies for COVID-19 after receiving two doses of its mRNA vaccine. Chief Health Editor Dr. Partha Nandi gives more details on the promising results.

Dr. Nandi:

Yes, the clinical data is certainly encouraging so I’m very happy to share the results from this study. Now, phase one of Moderna’s human safety tests included 45 participants between the ages of 18 and 55. All participants were split into three groups of 15. Each group received a different amount of the vaccine, either a 25, 100 or 250 microgram dose. And two weeks after the second dose was given, the folks in the 25 microgram group had antibodies at roughly the same levels as patients who had recovered from COVID-19. And the folks in the 100 microgram group had “significantly exceeded levels” than recovered patients. As for the third group, the ones given the highest dose of the mRNA vaccine, no data has been released yet regarding the second dose. Having said that it’s been reported that the biotechnology company is not moving forward with the 250 microgram dose in future trials.

Question: Were there any reported side-effects?

Moderna has said that the vaccine overall is generally safe. And that phase 1 did not produce any worrisome side-effects. Now there was some redness at the injection site for one patient. And three other patients that were given the highest dose had grade 3 systemic symptoms after the second shot. The company’s press release did not say what these were, but fever, muscle pain, and headache have been mentioned by Moderna’s Chief Medical Officer. And all of these symptoms were temporary.

Question: Do antibodies created by this vaccine mean it’ll kill the virus or protect a person from getting sick?

That’s a great question. When looking at Moderna’s animal studies, the vaccine given to mice did prevent the virus from multiplying in their lungs. But, I’ve said this before, success in animal studies does not guarantee success in humans. And it’s a bit early to say with certainty that these antibodies will protect the study’s participants against the coronavirus. Especially since it hasn’t been well studied and we’ve not sure if patients can get reinfected. However, there is some evidence that high levels of antibodies might neutralize the virus. So I remain hopeful. As for what’s next with Moderna potential vaccine, they’ll soon be moving forward with phase two of the trial, with plans for phase 3 to begin in July. And if all goes well, the vaccine could be ready in early 2021.