The Moderna Covid-19 vaccine created antibodies that neutralized coronavirus variants first found in the United Kingdom and South Africa, the company said in a news release on Monday.
Two doses of the vaccine “is expected to be protective against emerging strains detected to date,” according to the release.
The company’s study showed that the variant first found in the UK had “no significant impact” on the vaccine’s effectiveness.
The results for the variant first spotted in South Africa, however, were not as optimistic — and some early studies have suggested vaccines may be somewhat less effective against this strain.
In the press release, Moderna noted that “a six-fold reduction in neutralizing titers was observed with (the variant discovered in South Africa) relative to prior variants.”
The company said the vaccine was still expected to be effective.
“Despite this reduction, neutralizing titer levels with (the variant discovered in South Africa) remain above levels that are expected to be protective,” according to the press release.
David Montefiori, a virologist at Duke University Medical Center, said while he’s “cautiously optimistic” Moderna’s vaccine will work well against this strain, he’s still not sure.
“The efficacy might be reduced somewhat, but it may still be very effective,” he said. “Hopefully the vaccine will still be 70-80% effective.”
The variant first identified in the UK has also appeared in more than 45 other countries, including 195 cases in the US.
The variant first identified in South Africa has appeared in more than 20 other countries. No cases have been identified in the US, but experts say it’s likely there are cases and US surveillance, which has been widely criticized, has not yet found them.