Former secretary of state Colin L. Powell died Monday morning from complications related to covid-19. Powell’s disease resulted from a breakthrough infection; he was fully vaccinated against the coronavirus. But instead of demonstrating that the vaccine isn’t 100 percent effective in preventing death, which was known, his death better serves to show the need to tamp down on coronavirus cases more broadly to help protect those most at risk.

That group included Powell. He was 84 years old when he died, well into the elderly age group that has been most ravaged by the virus. He had also been diagnosed with multiple myeloma, which can reduce the body’s ability to fight infections.

Last week, the Centers for Disease Control and Prevention released data showing the effectiveness of vaccines in curtailing new infections and deaths from the coronavirus. In August, it found, those who were vaccinated were six times less likely to become infected and 11 times less likely to die of covid-19. But the data also showed a disparity in the death toll: The incidence of covid deaths among those age 80 and over was nearly as high as the incidence among the unvaccinated age 50 to 64.

This is not to say either that vaccines made no difference even among the most elderly or that the incidence of deaths among vaccinated elderly individuals was large. If we look at one week of the CDC’s data (the one in which the incidence of deaths was highest for those age 50 to 79), we see that the incidence of deaths among the unvaccinated was 21 times higher for those age 50 to 64, 15 times higher for those 65 to 79 and, among those 80 and older, more than four times higher.

Why the difference? For the very reason that so many people last year tried to diminish the danger posed by the virus. Older Americans have always been more at risk from covid, and the effects of the virus are clearly more pronounced with members of that age group even when they are vaccinated.

This should not be an impetus to nihilism, though. It’s not the case that this demonstrates that vaccines are futile or not useful. Instead, it’s a reminder that the virus still poses a risk to the elderly, even when vaccinated, and therefore that the goal should be to tamp down on the spread of the virus broadly. If Powell had been at little risk of contracting the virus because transmission rates were low, he would have been at almost zero risk of dying from it. But, instead, his death comes at a time when more than 80,000 people a day are still contracting the virus and more than 1,500 people are dying from it — about as many people as were dying in early April 2020.

The reason that health experts advocate vaccination is, in part, because it offers increased protection to individuals both from infection and death. But that, to some extent, is the icing on the cake. The broader advantage in widespread vaccination is that the virus has far less ability to spread, given how well protected the vaccinated are against contracting the virus. This is the goal of reaching herd immunity, creating a situation in which the virus can’t spread because it can’t find hosts without antibodies prepared to fight it. When the United States achieves herd immunity, 84-year-olds with preexisting conditions will be better protected against death simply because they will be at much lower risk of contracting the virus.

Johns Hopkins University epidemiologist Gypsyamber D'Souza explains how the U.S. can reach coronavirus herd immunity and what happens if that goal is missed. (Brian Monroe, John Farrell/The Washington Post)

As has long been the case, there are two paths to herd immunity. One involves a vaccine that is safe, free and effective. The other involves more people getting sick and building natural immunity. The risk with the latter, of course, is that it both increases the chances that the virus will spread in a community, and it poses a risk to the infected person. There is a risk, in other words, both to the individual and to the community, both of which are ameliorated through vaccination.

It seems inevitable in this moment that Powell’s death will prompt new indifference to the vaccine, as though his death somehow proves that the vaccines don’t work. The lesson we should learn instead is that the vaccines work best when they work broadly and that, had Powell been protected both by the vaccine and by low rates of infection in his community, he might still be alive.