Colin Powell, who died on Monday from COVID-19, had a blood-cell cancer that likely weakened his immune system

• Colin Powell, former US secretary of state, died on Monday from COVID-19 complications.
• Powell was vaccinated but was being treated for cancer, so he was likely immunocompromised.
• Immunocompromised people should take precautions recommended for unvaccinated people, the CDC says.

Colin Powell, former US secretary of state, died on Monday from COVID-19 complications, according to a statement from the Powell family.

Powell, who was 84, was treated at Walter Reed National Military Medical Center and was fully vaccinated, according to his family. He also had multiple myeloma, a white blood cell cancer, according to the New York Times. Cancer, as well as the drugs that treat the disease, can suppress the immune system. So both the disease and old age are risk factors for COVID-19 complications and death, according to the Centers for Disease Control and Prevention.

Multiple myeloma patients may be especially at risk, according to a small study published in Nature in July, which found that a third of patients with that diagnosis developed no immune response after the COVID-19 vaccine.

"He was over the age of 80, he had cancer, and a treatment for his cancer made him vulnerable," Dr. Jonathan Reiner, a CNN medical analyst and professor of medicine at George Washington University, told CNN. Powell, he added, "represented our most vulnerable population in this country."

Some public figures left out key context when reporting on Powell's death

Not all public figures mentioned those crucial details about Powell's health when reacting to his death Monday.

"The fact that Colin Powell died from a breakthrough COVID infection raises new concerns about how effective vaccines are long-term," Fox News anchor John Roberts wrote on Twitter.

Roberts has since deleted the Tweet.

Republican Rep. Matt Gaetz went a step further, telling his Twitter followers, "Post-vaccine breakthrough infection kills more people than Iraq's WMD's ever did."

"Powell's death should not be used to either explicitly or inadvertently push vaccine hesitancy," John Whitehouse, news director at Media Matters, wrote in a piece published Monday. "And more broadly it can serve as a reminder that the pandemic is certainly not over - and that loved ones across the country are still vulnerable."

Whitehouse also pointed out that the initial stories and Tweets published by the Associated Press and New York Times about Powell's death mentioned that he was fully vaccinated and had died of COVID-19, but not that Powell had cancer. Both organizations have since added context about Powell's multiple myeloma diagnosis.

COVID vaccines work well, but vulnerable people remain at risk

Data released by the CDC last week indicates that the three COVID-19 vaccines widely available in the US remain incredibly effective, even against the Delta variant.

As of August, unvaccinated people had a six-fold higher chance of testing positive for COVID-19 and an 11-fold greater chance of dying from the disease than those who got the shots. COVID-19 hospitalizations are about 12 times higher in unvaccinated adults than in vaccinated ones, the agency found.

But breakthrough cases do happen. Powell's death offers anecdotal evidence that vulnerable people, including older adults and those with compromised immune systems, may not mount a robust immune response to the vaccines so are therefore still at high risk.

"They should continue to take all precautions recommended for unvaccinated people, until advised otherwise by their healthcare professional," the CDC notes on its website, recommending as well that "moderately to severely immunocompromised people receive an additional dose of vaccine."