- COVID-19 vaccine efficacy against infection seems to have declined, a CDC scientist said.
- Dr. Sara Oliver said vaccines are still highly effective at preventing hospitalization.
- Vaccine effectiveness against hospitalization ranged from 75% to 95%.
COVID-19 vaccines are still highly effective against hospitalization despite the surge in the more transmissible Delta variant, a scientist with the Centers for Disease Control said on Monday.
In a presentation to the CDC’S Advisory Committee on Immunization Practices on Monday, Dr. Sara Oliver said that since Delta appeared, vaccine effectiveness against hospitalization ranged from 75% to 95%.
The vaccine’s ability to prevent infection ranged from 39% to 84% since the introduction of the Delta variant.
“Vaccines remain effective in preventing hospitalization and severe disease but might be less effective in preventing infection or milder symptomatic illness,” the presentation said.
The slides said both waning protection over time and the Delta variant may be contributing to the lower effectiveness of the vaccines.
Oliver said it’s not uncommon for some vaccines to require multiple doses, including vaccines for hepatitis and HPV. However, she said more information is needed before the group can assess the need for booster shots.
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, previously said the pandemic can be brought under control by next spring if the millions of people not yet vaccinated get their shots. The presentation said the top priority should be to vaccinate those Americans.
Experts have warned that the spread of the virus, specifically the Delta variant, could lead to a more dangerous variant.
“This is a very wily virus,” Fauci said. “If we keep lingering without getting those people vaccinated that should be vaccinated, this thing could linger on, leading to the development of another variant, which could complicate things.”
Those most at risk of severe disease should be prioritized for booster shots, the presentation added.
Oliver also said it’s important to ensure there is global vaccine availability. “Uncontrolled spread globally that could result in new variants threaten control of the pandemic everywhere,” her presentation said.