A health worker prepares to administer a dose of Johnson & Johnson Covid-19 vaccine to Khagendra Navajeevan Kendra, a rehabilitation center for people with disabilities, in Kathmandu.
SOPA Pictures | LightRocket | Getty Images
A Centers for Disease Control and Prevention advisory group examines whether fully vaccinated Americans with weakened immune systems need a booster dose of Covid-19 vaccines after data shows they are less likely to have antibodies to fight disease and more likely to suffer from a breakthrough infection.
Immunocompromised populations, such as patients living with cancer, HIV or who have had organ transplants, account for 44% of hospitalized breakthrough cases of Covid even though they represent around 2.7% of the US adult population, according to a slide presentation released Thursday as The Immunization Practices Advisory Committee met to discuss the need for recalls. The group also meets to discuss the security profile of the Johnson & Johnson vaccine.
They are also more likely to become seriously ill from Covid, the agency said, and are at higher risk of passing the virus on to family and friends.
Studies suggest that a third dose of the vaccine may help immunocompromised patients whose immune systems do not respond as well to a first or second dose. Four small studies cited by the CDC showed that between 16% and 80% of people with weakened immune systems did not have detectable antibodies to fight Covid after two injections.
Among immunocompromised patients who did not have a detectable antibody response, 33 to 50% developed an antibody response after receiving an additional dose, according to the CDC.
“Emerging data suggests that an additional dose of COVID-19 vaccine in immunocompromised people improves the antibody response and increases the proportion of those who respond,” according to a slide presented at the meeting.
The CDC meeting comes as federal officials say that booster doses of vaccines for the general population are not needed at this time.
The advisory committee cannot recommend additional injections for anyone until the Food and Drug Administration grants full approval of the Covid vaccines or changes emergency use authorizations.
Other countries, such as France, are already distributing third injections to people with cancer or other deficiencies in the immune system. The CDC group has previously said that the most vulnerable Americans, such as the elderly or transplant recipients, may require an additional dose.
Some doctors in the United States have been pushing for the United States to allow immunocompromised populations to receive an extra dose, according to Dr. Dan Barouch, an immunologist at Harvard Medical School who helped develop the J&J vaccine.
“The most difficult people to vaccinate are those who are immunocompromised,” he said, adding that early data shows that a third injection can be safe and effective for these populations.
CNBC’s Rich Mendez and Robert Towey contributed to this article.