If you want to get a COVID-19 vaccination but aren’t yet eligible, this can be a frustrating time. Over 1.9 million Americans are being vaccinated every day and the vaccine selfies on your newsfeed never seem to end. But it’s hard to know when you’ll be able to get your shot.
It’s easy to wonder whether there is a compelling rationale for rolling out the vaccine based on specific eligibility requirements. It seems excessively complicated. Surely just vaccinating as many people as possible, as quickly as possible, is a viable alternative. Is it really still best to use eligibility categories when the virus is spreading widely and new variants are circulating?
How COVID-19 vaccines work
Yes. Despite a slow start and an ongoing debate over whether prioritizing shots for the most vulnerable is the best option, the current scientific evidence clearly shows that prioritizing who gets a vaccination is well worth the effort. By strategically distributing the limited supply of doses we have, we’re reducing hospitalizations and deaths by as much as one-third, which lets us resume normal activities more quickly than if we used a first-come, first-served approach. There are too many other bottlenecks in vaccine distribution to assume that expanding eligibility would accelerate the pace of vaccination quickly enough to achieve better outcomes than our current strategy.
There are two potential overarching strategies to blunt the worst effects of the pandemic — hospitalizations and deaths — as quickly as possible: vaccinate the most vulnerable or vaccinate those most likely to spread the virus.
The case for vaccinating the most vulnerable is straightforward. The data shows that some Americans are far more at risk of hospitalization or death from COVID-19 depending on their age, specific underlying medical conditions, race and ethnicity and work from home status. For example, someone aged 65 to 74 is 73 times more likely to die of COVID-19 than someone aged 18 to 29. And someone with one of a specific set of underlying medical conditions is 2.5 times more likely to be hospitalized than someone of the same age, sex and race/ethnicity with no underlying medical conditions.
The alternative — vaccinating people most likely to spread the virus to reduce transmission and indirectly protect the most vulnerable — works well in theory. But it is tricky to design and implement. Policy makers would need to figure out who contributes most to transmission, craft guidelines that target them specifically and ensure they get the vaccine in high numbers, which can be a challenge since many are low-risk young adults. Ultimately, there is a lot we don’t know about how well this strategy would work in practice.
Several researchers have modeled COVID-19 transmission in the population to compare the impact of different prioritization strategies under a wide range of possible scenarios. Three studies found that strategies that focus on prioritizing the vulnerable for vaccination are more effective at preventing severe illness than the alternative strategy of prioritizing those with the highest transmission rates. Two other studies found that prioritizing those most likely to spread COVID-19 was a better strategy. However, both assumed that the vaccines would prevent less than 70 percent of serious illness, which is less effective than they actually are.
Essentially, giving the vaccine to anyone who wants it might be a better plan if the vaccines weren’t so great at helping the most vulnerable. But that’s just not our reality.
The current evidence demonstrates that vaccination strategies that protect the most vulnerable by vaccinating them directly will prevent more hospitalizations and save more lives than strategies that aim to reduce overall transmission. Not only do these strategies perform better in modeling studies but they are also more likely to be successful in practice since they present fewer design and implementation challenges. Besides, many places are already reducing overall transmission by prioritizing essential workers, who tend to have more contacts than those working from home.
It’s true that relaxing prioritization could increase the pace of vaccinations. But it would have to almost double the pace to exceed the benefits of the current strategy, which prioritizes people who are more than twice as likely to be hospitalized or die, thereby more than doubling the impact of each dose.
It’s not easy for a state to double the pace of vaccinations overnight. Based on all the reports of eligible people struggling to get vaccination appointments, a common limiting factor is available slots, rather than people to fill them. Florida expanded eligibility to everyone 65 and older early in the rollout but has ranked 24th, on average, in per capita vaccinations whereas West Virginia has been among the leaders in per capita vaccination rates while also staying focused on prioritization.
If our goal is to mitigate the worst effects of the pandemic and bring it to an end sooner, then easing up on prioritization is counterproductive. But there is one option that almost guarantees a massive payoff: expanding funding for vaccination programs, which can improve outreach to eligible people and speed the pace. This is increasingly urgent since the supply of available vaccine doses is expected to nearly double by the end of March.
Everyone is weary of the pandemic and eager to get back to normal, but the solution isn’t to give up on our vaccination strategy. We expect to have doses for the entire U.S. adult population by the end of May. In the meantime, investing in vaccination programs that efficiently and strategically distribute vaccine doses can help us get closer to normal before then. And it will speed the process for the rest of us when it’s our turn.