UCHealth doctor supports booster shot for people with weak immune systems

UCHealth Preparing for New Vaccine Group
Posted at 11:52 PM, Aug 04, 2021

DENVER — A UCHealth doctor says a booster shot for people with weak immune systems could help protect their health and slow down the spread of COVID-19.

Dr. Thomas Campbell, a professor of medicine and chief clinical research officer for UCHealth, said people who are immunosuppressed — which includes people battling cancer, people with chronic conditions that require treatment and those who have received an organ or bone marrow transplant — are at a higher risk of a breakthrough case. That means they can contract the virus even if they are fully vaccinated, according to Campbell.

“What we know is that people who are immune-compromised who have breakthrough infections have a very high risk of getting severely sick and being hospitalized, and they have a risk of death,” Campbell said.

Campbell oversaw two major clinical trials for COVID-19 vaccines at UCHealth University of Colorado Hospital and on the Anschutz Medical Campus. He says while the vaccines available are up to 94% effective, people with compromised immune systems are less responsive to the shot, and their effectiveness drops between 50 and 40%.

“Their immune systems are suppressed, so they don’t make the high level of antibodies that are needed to protect against COVID,” Campbell said. “What we do know is that immunosuppressed individuals, after getting, say, two doses of Pfizer or Moderna vaccines, about half the time they don’t have any detectable antibody level at all.”

Most vaccines, including the influenza shot, have shown to be less successful among people with weak immune systems.

To help protect the population from the deadly virus, Campbell strongly suggests approving a booster shot.

“The evidence is there that immunosuppressed individuals need a booster, and they need it now,” Campbell said.

He admits more evidence is needed to fully understand how much protection another shot will provide and for how long.

The CDC is considering a third shot for people with compromised immune systems, but no decision has been made.

“I think it should be rolled out today, but we are not there,” Campbell said.

On Wednesday, the World Health Organization called for a halt on the booster shot through the end of September so the current supply can go to those who need their first or second dose. But Campbell questions that move.

“I don’t think that giving that select subgroup of individuals a third dose is going to have a big impact on our efforts to expand vaccine access around the world,” Campbell said.

He said people that are immunocompromised make up less than 2% of the population in the U.S. and can spread the virus at a greater rate if they’re not protected.

“They will shed virus in their upper respiratory tract at higher levels and for longer periods of time than people who are not immunosuppressed”

He strongly advises people with compromised immune systems to wear masks, socially distance and wash their hands.