It turns out that determining who gets a COVID-19 vaccine first can be nearly as challenging as developing the vaccine itself.

The timeline is a big part of the challenge. Historically, most vaccines were developed years or even centuries after a disease emerged, so there was a good understanding of how the disease spread and affected various age groups and populations. That understanding helped direct vaccine allocation and priorities.

Given the urgency of the current pandemic, COVID-19 vaccines went into development just weeks after the virus started spreading throughout the world, so “the uncertainties that we have are overwhelming,” said William Foege, co-chair of the National Academies of Sciences, Engineering, Medicine’s committee charged with developing a framework for allocating a vaccine once it’s available in the U.S.

The unknowns include epidemiology questions, the type of vaccine that may be approved and a vaccine’s impact on various age groups. To date, no COVID-19 vaccine trial has enrolled children, Foege said.

Despite the unanswered questions, the committee had to prioritize who should get the first doses of a vaccine. The draft framework is based on the expectation that the initial rollout of a vaccine would be enough to immunize just 3% to 5% of the U.S. population.

“We did the best we could,” Foege said at a Sept. 2 public meeting aimed at getting feedback on the draft discussion framework the committee released this week.

The purpose of the meeting was to make sure the committee doesn’t miss any important perspectives as it moves forward on a final plan, committee co-chair Helene Gayle said.

When facing vaccine allocation challenges in the past, experts always started with the science, Foege said. This time, with the pandemic laying bare the inequities in health care and the disproportionate impact COVID-19 has had on minority communities, the committee started backwards, beginning with ethics before going to the science.

But rather than prioritize vaccine allocation based on race or ethnicity, the committee looked at factors that have led to the disproportionate impact – vulnerabilities like high body mass index, heart or kidney problems, crowded living conditions and multigenerational occupancy. “This virus doesn’t understand skin color at all, but it understands vulnerabilities,” Foege said.

Several speakers representing minority communities at the public hearing weren’t satisfied with that approach. For instance, Ellen Provost, director of the Alaskan Native Tribal Health Consortium’s Alaskan Native Epidemiology Center, said Alaskan natives should be placed in the highest priority group, noting that the incident of COVID-19 is 3.5 times greater among American Indians and Alaskan Natives than in non-Hispanic whites.

Provost pointed out that Alaskan Natives, half of whom live off the road system, are explicitly named as a high-risk group for flu vaccines, adding that it should be the same with the COVID-19 vaccine.

In the draft framework, the highest priority group, or phase I, starts with frontline health workers, based on their actual risk of exposure to the coronavirus, followed by first responders. Together, those two groups make up about 5% of the population. The second part of phase I would extend the vaccine to an additional 10% of the population – people with significant co-morbidities and older adults living in long-term care facilities or crowded settings.

Some speakers underlined omissions in the framework. Winston Wong, chair of the National Council of Asian Pacific Islander Physicians, said that while the framework discussed the need to mitigate health inequities among various minorities, it failed to mention the high toll of COVID-19 on Pacific Islanders. He said that Marshall Islanders living in Arkansas and Oklahoma are seeing a higher incidence than any other groups in those states. And COVID-19 is three times higher in Native Hawaiians than in others in that state.

Michelle Hood, executive vice president and chief operating officer of the American Hospital Association, pointed out another omission. The framework doesn’t include mental health as a co-morbidity, but it is a significant risk, she said.

Other speakers offered advice on defining categories, such as first responders and essential workers, in the framework. First responders should include a broad range of emergency service agencies, dispatchers and other support staff, said David Gerstner, of the Dayton (Ohio) Metropolitan Medical Response System. The CDC had included workers in such services in the top tier in the past, but that changed in the 2009 H1N1 epidemic. During that health crisis, emergency service workers who helped with the immunization program were themselves denied the vaccine, Gerstner said.

Not all the comments focused on who was in which phase. Some speakers offered advice on who should be involved in distributing and administering the vaccines and stressed the need for consistent messaging and education.

Marcus Plescia, the chief medical officer for the Association of State and Territorial Health Officials, said the framework should reinforce the role of the CDC’s Advisory Committee on Immunization Practices while giving flexibility to states so distribution can be customized at the state level. It also needs to emphasize a unified approach and the messaging around the vaccine, he said, adding that “discord among leaders at any level will erode public trust.”

Foege clarified that the final vaccine allocation framework and report will be recommendations. The real decisions, he said, will be made at the CDC and at the tribal, state, county and local levels.