RELATED: Pfizer says early data signals COVID-19 vaccine is 90% effectiveThe company has not yet released detailed data on its study, and results have not been analyzed by independent experts.Pfizer said its vaccine was more than 94% effective in adults over age 65, though it is not clear how the company determined effectiveness in older adults, with only eight infections in the vaccinated group to analyze and no breakdown provided of those people’s ages.AdvertisementAn illustration picture shows vials with Covid-19 Vaccine stickers attached and syringes with the logo of US pharmaceutical company Pfizer, on November 17, 2020. (Photo by JUSTIN TALLIS / AFP) (Photo by JUSTIN TALLIS/AFP via Getty Images) Earlier this week Moderna, Inc..