Harvard Medical School, Boston Children’s study charts path for fighting COVID-19 variants with vaccines

Researchers at Harvard Medical School and Boston Children’s Hospital are proposing a possible way to make COVID-19 vaccines more effective against variants first detected in the United Kingdom, South Africa, and Brazil.

The findings are contained in a new study published online March 16 in the journal Science, according to a statement posted to the med school’s website.

The study says the researchers focused on the D614G mutation present in all the variant strains. That mutation, the medical school said, stabilizes the virus’s “spike protein,” allowing more spikes to bind to human cells’ ACE2 receptors, which makes the virus more infectious.

Since most vaccines — including from Pfizer, Moderna, Johnson & Johnson, and AstraZeneca — are based on the original coronavirus spike protein, the researchers suggest that “adding the D614G mutation could make the vaccines better able to elicit protective neutralizing antibodies against the viral variants,” the statement said.

Dr. Bing Chen, a Harvard Medical School professor of pediatrics at Boston Children’s, served as lead author of the study, according to the statement, which said Dr. Jun Zhang and Dr. Yongfei Cai, both research fellows at Boston Children’s, were first co-authors.

“The SARS-CoV-2 S protein is the centerpiece of the first-generation vaccines that almost all used the D614 sequence,” the study says. “The G614 S trimer is naturally constrained in a prefusion state that presents both the RBD-down and RBD-up conformations with great stability. It is therefore likely to be a superior immunogen for eliciting protective neutralizing antibody responses, … [and] may also be an excellent scaffold for designing next-generation vaccines against new variants that have become resistant to protections offered by the existing vaccines.”

The study on the variants comes as Massachusetts officials said earlier this week that the state has now seen 441 confirmed cases of the worrisome coronavirus variant that first emerged in Britain.

The state has also seen four cases of the variant that emerged in Brazil, and nine cases of the variant that emerged in South Africa, according to figures posted Tuesday evening on the US Centers for Disease Control and Prevention website and confirmed by the state health department.

The CDC said the numbers are based on just a sampling of specimens and do not represent the total number of cases that may be circulating. The agency said it’s “monitoring the situation closely.”

The British variant spreads more easily and quickly. Some studies have suggested it is also more deadly. CDC models project the variant will become the dominant strain in the United States by the end of this month or early April.

Officials are worried the variants could drive a new coronavirus surge even as the country races to get people vaccinated.

“Obviously, we’re continuing to see variants here in Massachusetts, which is consistent with what people are seeing in other places,” Governor Charlie Baker told a legislative committee Tuesday. “But I think in some ways where we are in Massachusetts, both with respect to the case counts, hospitalizations, positive test rates, and all the rest, is not the same place that many other states are in. And, as a result, we’ve tried to tailor the decisions we’ve made to be consistent with that.”

Material from prior Globe stories was used in this report.

Travis Andersen can be reached at [email protected]. Follow him on Twitter @TAGlobe.