Vials of the Pfizer-BioNTech vaccine are pictured in a vaccination centre in Geneva, Switzerland, February 3, 2021. REUTERS/Denis Balibouse
The Food and Drug Administration last week granted full approval to the vaccine that was previously available under the agency's emergency use authorization , which had allowed the shots to be rolled out rapidly to Americans. Some panel members said increasing vaccinations before the fall season was critical to getting children back to schools safely.
CDC staff presented available data on the need for boosters and said, at this point it may be difficult to determine whether immunity from prior vaccination is waning over time or if the vaccines are just less able to prevent infection by the highly-transmissible Delta variant.