Yale research finds vaccine effective against coronavirus variant found in Brazil

NEW HAVEN — A vaccine made from inactivated coronavirus has shown to be effective against the virus variant discovered in Brazil, according to a Yale University release.

Researchers from Brazil and the Yale School of Public Health used CoronaVac, made by Sinovac Life Sciences in Beijing, in the city of Manaus, Brazil.

The variant, known as P.1, has been largely responsible for 337,000 deaths in Brazil, second in the world after the United States. The country recently suffered 4,000 deaths in one day and the country’s health care system is unable to cope with the disease.

CoronaVac was shown to be 50 percent effective 14 days after the first of two doses, according to the release. The study involved almost 70,000 health care workers in Manaus, where the variant emerged.

“The majority of people in the study had only received their first vaccine dose. Overall effectiveness may turn out to be higher as more people receive their second dose,” said lead investigator Dr. Julio Croda, a senior researcher at the Oswaldo Cruz Foundation, Brazilian Ministry of Health, and adjunct professor at the Yale School of Public Health, in the release.

“This is a critically important finding for it tells us that ramping up vaccination will turn the tide against the devastating resurgence we are experiencing in Brazil due to the spread of the P.1 variant,” he said. More data will be analyzed after patients receive their second dose.

“This variant has not only created a public health emergency in Brazil but is a threat to other countries in South America and beyond,” said Dr. Albert Ko, a professor at the Yale School of Public Health who works extensively in Brazil and is a co-author of the study, in the release.

“National leaders and the global community need to secure the needed vaccine supply and deploy them as quickly as possible, in addition to implementing sound public health prevention, to preempt the impending humanitarian crisis,” he said.

This is the first study of a COVID-19 vaccine in an area where the variant is widespread. The findings are published on MedRxiv, a website that posts research before publication. The study has been submitted for scientific peer review.

The P.1 variant was first identified in Manaus in December 2020 and has spread around the world, including the United States. The World Health Organization has declared it a “variant of concern” because it is highly contagious and the first vaccines may not be as successful against it.

Croda said CoronaVac and the AstraZeneca vaccines would be tested in the general population of Manaus, Campo Grande and São Paulo. The research is overseen by VEBRA-COVID, a consortium that includes researchers from Brazil, the Pan-American Health Organization, University of Florida and Stanford University, among other international partners.