Watch: When disease impairs immunity, vaccines are hampered, too

Covid-19 vaccines are remarkably effective, and, at this point, they are the best tool we have against the pandemic. But for people who are immunocompromised, like cancer patients, the regular course of shots may offer little to no protection.

Former Secretary of State Colin Powell died at 84 last week from complications of Covid, despite being fully vaccinated. Powell also had multiple myeloma, a cancer that affects plasma cells. While many conditions can make people more vulnerable to breakthrough illness, multiple myeloma is among the riskiest.

Treatment for multiple myeloma targets abnormal immune cells, but will often kill normal ones in the process. “Receiving treatment for multiple myeloma really impairs patients’ ability to fight off an infection and impairs their ability to gain the protections that the rest of us get from the vaccine,” said Adam Sperling, a medical oncologist who specializes in multiple myeloma at Dana-Farber Cancer Institute in Boston.

Multiple myeloma is most commonly diagnosed in people over 60, a demographic that is already at higher Covid risk. The combination of Powell’s cancer and his age likely significantly decreased protection provided by the vaccine. Immunity from vaccination depends on a functioning immune system to create antibodies. Powell was planning to receive a third vaccine dose when he fell ill.

Blood cancers like multiple myeloma aren’t the only conditions that can leave patients more susceptible to devastating infections like Covid-19. Organ transplant recipients, for example, are given drugs that intentionally suppress their immune system to keep their bodies from rejecting the new organ.

“If we [non-immunocompromised people] got a breakthrough infection … we might feel like crap for a little while. We might get long Covid. But it’s very, very unlikely that we’ll die. If you’re a transplant patient and you get a breakthrough infection, you have a 10% mortality from that,” said Dorry Segev, founder and director of the Epidemiology Research Group in Organ Transplantation and associate vice chair of surgery at Johns Hopkins University.

Segev’s group published a study in September that showed an additional vaccine dose increased antibodies in organ transplant recipients who previously had little or no antibodies to the virus. The Food and Drug Administration has also authorized an additional dose of the mRNA vaccines from Pfizer-BioNTech and Moderna for people who are immunocompromised; these are considered a third dose, as opposed to the boosters that have become available for many adults.

The fact that Covid can spread from people who aren’t showing symptoms makes protecting immunocompromised people even more important. “The person who gave Colin Powell Covid … likely didn’t know that [they] were spreading Covid at the time,” said Sergev. “The only way to prevent asymptomatic spread is having as many antibodies as possible, which means getting vaccinated.”