New research by an international team of scientists from the Yale School of Public Health (YSPH) and the Oswaldo Cruz Foundation in Brazil among others has found vaccination highly effective in protecting the elderly during an epidemic where the COVID-19 Gamma variant is prevalent. The study results are posted on MedRxiv as a preprint paper.

According to the study’s co-principal investigator, Albert Ko, the Raj and Indra Nooyi Professor of Public Health at YSPH, “The good news is that the ChAdOx1 vaccine was highly effective in protecting the elderly during an epidemic where the Gamma variant caused more than 80% of the cases. However, unlike the experience with ChAdOx1 in other settings, two doses are needed to reach optimal levels of protection in this vulnerable population and in the setting of extensive Gamma variant transmission.”

The findings have significant implications for Brazil as well as other countries in South America which have been particularly hard hit by the pandemic. The study was performed by the VEBRA-COVID consortium, which includes researchers from Brazil and international partners, which include Oswaldo Cruz Foundation, Federal University of Mato Grosso do Sul, Nacional University of Brasilia, Barcelona Institute for Global Health, University of Florida, Stanford University, Health Secretary of São Paulo state, the Pan-American Health Organization and the Yale School of Public Health. 

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Visit the YSPH website to learn more about the study.

Visit the Yale and Brazil Partnerships & Programs page to learn more about Yale’s collaborations in Brazil.