In an interview with CBS Evening News’ Norah O’Donnell, Microsoft co-founder and billionaire philanthropist Bill Gates said that it is likely that an effective coronavirus vaccine will require multiple doses.
“None of the vaccines at this point appear like they’ll work with a single dose,” Gates said. “That was the hope at the very beginning. Maybe one of them particularly in the second generation will surprise us. We hope just two, although in the elderly sometimes it takes more, and so making sure we have lots of elderly people in the trial will give us that data.”
He noted that to block all transmission of the virus, there needs to be 70 to 80 percent coverage globally. Gates has previously said that global effort may require up to 7 billion doses.
During a House Subcommittee on Oversight and Investigations of the Committee on Energy and Commerce hearing on Tuesday, Merck’s executive vice president and chief patient officer Dr. Julie Gerberding said that there may even be more than one vaccine needed depending on how well higher-risk populations like the elderly respond.
“At the very beginning of vaccine development, we tend to study vaccines in the people who have the greatest likelihood of responding to the vaccine, but we do need to understand what will happen with these vaccines in older people,” Gerberding said. “That’s one of the reasons why I think we are going to ultimately end up with more than one vaccine. The first vaccine might not be the best vaccine for seniors, or for children, so we need to have additional studies to really define the value in the highest risk populations and the safety in those high-risk populations.”