Why older adults must go to the front of the vaccine line

January 21, 2021

Vaccinating older adults for COVID-19 first will save substantially more U.S. lives than prioritizing other age groups, and the slower the vaccine rollout and more widespread the virus, the more critical it is to bring them to the front of the line.

That's one key takeaway from a new University of Colorado Boulder paper, published today in the journal Science, which uses mathematical modeling to make projections about how different distribution strategies would play out in countries around the globe.

The research has already informed policy recommendations by the Centers for Disease Control and the World Health Organization to prioritize older adults after medical workers.

Now, as policymakers decide how and whether to carry out that advice, the paper--which includes an interactive tool--presents the numbers behind the tough decision.

"Common sense would suggest you want to protect the older, most vulnerable people in the population first. But common sense also suggests you want to first protect front-line essential workers (like grocery store clerks and teachers) who are at higher risk of exposure," said senior author Daniel Larremore, a computational biologist in the Department of Computer Science and CU Boulder's BioFrontiers Institute. "When common sense leads you in two different directions, math can help you decide."

For the study, Larremore and lead author Kate Bubar, a graduate student in the Department of Applied Mathematics, teamed up with colleagues at the Harvard T.H. Chan School of Public Health and the University of Chicago.

They drew on demographic information from different countries, as well as up-to-date data on how many people have already tested positive for COVID-19, how quickly the virus is spreading, how fast vaccines are rolling out and their estimated efficacy.

Then they modeled what would happen in five different scenarios in which a different group got vaccinated first: Children and teenagers; adults ages 20 to 49; adults 20 or older; or adults 60 or older (considering that about 30% of those eligible might decline). In the fifth scenario, anyone who wanted a vaccine got one while supplies lasted.

Results from the United States, Belgium, Brazil, China, India, Poland, South Africa, Spain and Zimbabwe are included in the paper, with more countries included in the online tool.

Different strategies worked better or worse, depending on local circumstances, but a few key findings jumped out.

In most scenarios, across countries, prioritizing adults 60+ saved the most lives.

"Age is the strongest predictor of vulnerability," said Larremore, noting that while pre-existing conditions like asthma boost risk of severe illness or death, age boosts vulnerability more. "You have an exponentially higher likelihood of dying from COVID-19 as you get older."

The authors also note that, while the vaccines being distributed now are believed to have about a 90 to 95% chance of protecting against severe disease, researchers don't yet know how well they block infection and transmission. If they don't block it well and asymptomatic spreaders abound, it again makes the most sense to vaccinate older adults. If nothing else, they'll be personally protected against grave disease.

Only in scenarios where the virus is under control and the vaccine is known to block infection and transmission well does it make sense to move younger adults to the front of the line. That is not the situation in the United States right now.

"For essential workers who might be frustrated that they are not first, we hope this study offers some clarity," said Bubar. "We realize it is a big sacrifice for them to make but our study shows it will save lives."

So will a faster rollout, they found.

For instance, all other things being equal, if the rollout speed was to be doubled from current rates under current transmission conditions, COVID-19 mortality could be reduced by about 23%, or 65,000 lives, over the next three months.

The paper also suggests that in some situations where COVID has already infected large swaths of the population and vaccine is in short supply, it might make sense to ask younger adults who have already tested positive to step to the back of the line.

"Our research suggests that prioritizing people who have not yet had COVID could allow hard-hit communities to stretch those first doses further and possibly get to some of the herd immunity effects sooner," said Larremore.

The authors stress that vaccines alone are not the only tactic for helping win the race against COVID.

"To allow the vaccine to get to folks before the virus does, we need to not only roll out the vaccine quickly and get it to the most vulnerable people. We have to also keep our foot on the virus brake with masks, distancing and smart policies," said Larremore.

University of Colorado at Boulder

Related Public Health Articles from Brightsurf:

COVID-19 and the decolonization of Indigenous public health
Indigenous self-determination, leadership and knowledge have helped protect Indigenous communities in Canada during the coronavirus disease 2019 (COVID-19) pandemic, and these principles should be incorporated into public health in future, argue the authors of a commentary in CMAJ (Canadian Medical Association Journal) http://www.cmaj.ca/lookup/doi/10.1503/cmaj.200852.

Public health consequences of policing homelessness
In a new study examining homelessness, researchers find that policy such a lifestyle has massive public health implications, making sleeping on the street even MORE unhealthy.

Electronic health information exchange improves public health disease reporting
Disease tracking is an important area of focus for health departments in the midst of the COVID-19 pandemic.

Pandemic likely to cause long-term health problems, Yale School of Public Health finds
The coronavirus pandemic's life-altering effects are likely to result in lasting physical and mental health consequences for many people--particularly those from vulnerable populations--a new study led by the Yale School of Public Health finds.

The Lancet Public Health: US modelling study estimates impact of school closures for COVID-19 on US health-care workforce and associated mortality
US policymakers considering physical distancing measures to slow the spread of COVID-19 face a difficult trade-off between closing schools to reduce transmission and new cases, and potential health-care worker absenteeism due to additional childcare needs that could ultimately increase mortality from COVID-19, according to new modelling research published in The Lancet Public Health journal.

The Lancet Public Health: Access to identification documents reflecting gender identity may improve trans mental health
Results from a survey of over 20,000 American trans adults suggest that having access to identification documents which reflect their identified gender helps to improve their mental health and may reduce suicidal thoughts, according to a study published in The Lancet Public Health journal.

The Lancet Public Health: Study estimates mental health impact of welfare reform, Universal Credit, in Great Britain
The 2013 Universal Credit welfare reform appears to have led to an increase in the prevalence of psychological distress among unemployed recipients, according to a nationally representative study following more than 52,000 working-age individuals from England, Wales, and Scotland over nine years between 2009-2018, published as part of an issue of The Lancet Public Health journal on income and health.

BU researchers: Pornography is not a 'public health crisis'
Researchers from the Boston University School of Public Health (BUSPH) have written an editorial in the American Journal of Public Health special February issue arguing against the claim that pornography is a public health crisis, and explaining why such a claim actually endangers the health of the public.

The Lancet Public Health: Ageism linked to poorer health in older people in England
Ageism may be linked with poorer health in older people in England, according to an observational study of over 7,500 people aged over 50 published in The Lancet Public Health journal.

Study: Public transportation use linked to better public health
Promoting robust public transportation systems may come with a bonus for public health -- lower obesity rates.

Read More: Public Health News and Public Health Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.