Science‘s COVID-19 reporting is supported by the Pulitzer Center.
When and if the world has a COVID-19 vaccine, who should get it first? That question came into sharp relief last week. A committee that makes vaccine use recommendations to the U.S. Centers for Disease Control and Prevention (CDC) wrestled with the issue in a virtual meeting, and new data suggested how fraught any prioritization is likely to be: Pregnant women—normally the last to receive a new vaccine, given the possibility of harm to a fetus—may have an increased risk of severe illness from COVID-19, suggesting they should be high on the list.
Bruce Gellin, former director of the U.S. government’s National Vaccine Program who now helps lead the nonprofit Sabin Vaccine Institute, says the prioritization issue comes down to a tricky balancing act between best helping society versus protecting an individual’s health. “These are tough decisions, because everybody can make a case for why somebody should be ahead of somebody else in line,” he says. “Nobody’s going to debate health care workers and first responders—people who are putting themselves at risk for others and keeping things moving. After that is when it gets complicated.”
The new coronavirus’ disproportionate toll on the elderly could put them at the front of the line—except they often have the weakest response to vaccines. Conversely, groups such as prisoners, meat packers, soldiers, and grocery store workers are often young and healthy—yet their profession or environment dramatically increases risks of getting infected. And then there is the thorny question of whether to favor specific ethnic groups hard-hit by the virus.
Even if the optimists are right and a COVID-19 vaccine is approved for widespread use as early as this fall, it is likely to be in short supply at first. Agencies such as CDC and the World Health Organization (WHO) are racing to plan for that possibility. Ahead of last week’s meeting, a subgroup of CDC’s Advisory Committee on Immunization Practices (ACIP) borrowed from a plan made for scare pandemic influenza vaccines and developed a rough, five-tier scheme for the United States. The top tier includes 12 million people referred to as “critical health care and other workers,” with the first doses going to a subset of these people who are the “highest risk medical, national security, and other essential workers,” CDC’s Sarah Mbaeyi explained.
Tiers two and three would include 110 million people who also work in health care and other essential jobs, or are in these groups: 65 and older, living in long-term care facilities, or those with medical conditions known to increase the risk of developing severe COVID-19. The final two tiers would somehow preferentially allocate vaccine to the “general population” of 206 million people.
WHO on 18 June laid out its own rough “strategic allocation.” It would give priority to nearly 2 billion people, lumping together “healthcare system workers,” adults older than 65 or as young as 30 if they are at higher COVID-19 risk because they have comorbidities such as cardiovascular disease, cancer, diabetes, obesity, or chronic respiratory disease.
But those schemes have somewhat vague group descriptions that leave many questions unanswered, and in a 25 June meeting the ACIP working group turned to the full committee for guidance. COVID-19 has had a disproportionate impact on Black, Latino, and Native American communities. “Should race or ethnicity be a criterion?” Mbaeyi asked. José Romero, a pediatric infectious disease specialist at Arkansas Children’s Hospital Research Institute who chairs ACIP, thought these populations should get prioritization. “If we fail to address this issue … whatever comes out of our group will be looked at very suspiciously and with a lot of reservation.”
Members of the full ACIP added questions of their own. Who, exactly, is a “high-risk” medical worker, given that nurses and physicians in COVID-19 units have the best protective gear, whereas others in the same hospitals may have bureaucratic jobs and don’t interact with patients? Should the poor be given preference because they have less access to health care, live in more crowded conditions, and suffer more if they become sick and must take time off work? What about people who live in homeless shelters? How about teachers who are indoors with large groups of students?
Pregnant women present particularly vexing issues. The new data, reported in CDC’s Morbidity and Mortality Weekly Report, compared more than 90,000 women with confirmed cases of COVID-19 who were between 15 and 44. The study has several important limitations, but in an age-adjusted analysis, the 8200 women who were pregnant had a 1.5 times higher risk of being admitted to an intensive care unit and a 1.7 times higher risk of requiring mechanical ventilation. “That is fairly compelling evidence” pregnant women should be prioritized for a vaccine, though their risk isn’t pronounced as the elderly,” says Denise Jamieson, an obstetrician/gynecologist at Emory University who is not an ACIP member.
Sonja Rasmussen, a pediatrician at the University of Florida who has collaborated with Jamieson on studies of different infections during pregnancy, says it may turn out that having COVID-19 harms not only mothers, but fetuses in the first trimester. “We’re trying to make really tough life-and-death decisions, and I don’t think we can go too far making recommendations right now because we’re still collecting data,” Rasmussen says.
Ezekiel Emanuel, a bioethicist at the University of Pennsylvania, says there’s even room for debate about the assumption that the elderly should receive the vaccine early. Emanuel, who stresses that he is not recommending “sacrificing” older people for the young, says it may nonetheless make more sense to prioritize vaccinating younger people who develop stronger immune responses than the elderly do. “You try to get to herd immunity with people who are going to react well,” he says. The less virus in circulation, the less risk to the elderly.
Tom Frieden, who headed CDC in 2009 during an influenza pandemic when a vaccine was in short supply, recalls the debates that erupted within the agency and the outside pressures it experienced. He foresees intense lobbying as a COVID-19 vaccine nears reality. “There may be groups that from a societal or health standpoint may not appropriately be in tier one but are quite insistent on it,” says Frieden, who now heads the Resolve to Save Lives initiative that combats epidemics.
Frieden says he was impressed by the ACIP discussions but stresses that even when it comes time to make the recommendations—ACIP will meet again on this issue in August and WHO plans to finalize allocation plans by the end of that month—the data will remain imperfect. “If you waited until you had perfect data about this issue, you would never act,” he says. “It’s not premature to plan for this.”