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As the Delta variant surges across almost all states in the U.S. causing local outbreaks, getting more people vaccinated against the virus that causes Covid-19 should be the country’s key goal.

Even though 72% of Americans age 18 and older have received at least one dose of a Covid-19 vaccine — one of the highest vaccination rates in the world — it isn’t enough.


Mass vaccination campaigns peaked in April and the number of doses administered daily have slowed considerably in all 50 states. To get more Americans vaccinated, it’s time to harness the concern generated by outbreaks and focus vaccination resources on people being exposed to the virus. It’s time to really integrate vaccination efforts into systems for testing and contact tracing.

There are many reasons why some people have not yet been vaccinated. It can’t be simplified to a single term like “hesitancy.” There are some hard core anti-vaxxers, but most as-yet unvaccinated people are in the “wait and see” category. They have questions about the vaccine, how it was tested, and its potential benefits to themselves and those around them. Maybe they would like to have a conversation about vaccination with someone who speaks their language. Others may not be able to take time off from work for an appointment. They need a nudge in the right direction.

An outbreak can be a powerful motivator to spur the wait-and-see crowd to take action.


Look at the vaccination numbers in the past few weeks. They are surging in states like Florida, Arkansas, Missouri, and Louisiana with the highest case counts. People of all political persuasions are getting vaccinated because they are scared of getting infected with Delta. Although the public health messaging to get vaccinated hasn’t changed for months, the Delta surge is making people listen.

This is a common phenomenon with infectious diseases. When one hits close to home, people become more interested in prevention. For example, unvaccinated people are posting on social media from their hospital beds about their regret at not getting vaccinated and encouraging others to get the vaccine. Those who aren’t sick themselves but who know someone who is sick with Covid-19 are going to be more interested in vaccination. For most people, self-preservation is a powerful motivator.

Now is a good time to tip the scales for those on the fence. Large and small Delta outbreaks are happening all over the U.S., not just in a few states. The personal impact of a local outbreak is a strong motivator to get vaccinated — maybe stronger than the large ones.

For someone working at a factory, learning that five co-workers are out with a positive test might be a big deal. For a churchgoer, learning that a couple of families have gotten sick with Covid-19 can be a shock. For young people partying at nightclubs, learning about an outbreak at the local hangout might push vaccination to the top of their mental to-do lists. Up close and personal connections to Covid-19 tend to prompt unvaccinated people to get jabbed immediately.

Even better, there’s a fast and easy way to find these people all over the U.S. and ramp up vaccinations nationwide. They enter testing and contact tracing systems every day. Surprisingly, there is no systematic effort to persuade the unvaccinated among them to get vaccinated.

Between 500,000 and 2 million Americans get tested for SARS-CoV-2 every day at community testing facilities, pharmacy chains, doctor’s offices, and other sites. These people tend to be unvaccinated because, until recently, the CDC recommended that fully vaccinated people didn’t need to be tested even if they had been in close contact with an infectious case.

From an operational point of view, the best opportunity to vaccinate people is when they come in for a Covid test. Since January 2021, the national rate of positive tests has generally ranged from 2% to 10%, meaning that 90% or more of people tested each day have not been infected with SARS-CoV-2, the virus that causes Covid-19. Those who receive a negative result will never be contacted again, and the opportunity to vaccinate these high-risk individuals has been lost.

People generally seek testing because they are worried they might have Covid-19, and so might be uniquely receptive to a discussion about vaccination. Yet there is no active effort to help unvaccinated people get vaccinated throughout the entire testing process. Vaccination information should be integrated into all aspects of the testing system. When someone makes an online booking, the website should suggest that they get vaccinated at the same time they have the test. The person collecting the sample should explain that vaccination is available and link them to a colleague who can do it on the spot.

One barrier is that CDC recommendations are not explicitly clear about whether people can be vaccinated on the same day they are tested. This is largely an operational issue, not a medical one, but with more than one billion people worldwide having received at least one dose of a Covid-19 vaccine, there have undoubtedly been many who were already ill with Covid-19 and did not experience any adverse effect from vaccination.

In addition to testing, contact tracing is another opportunity to convince high-risk unvaccinated people to get vaccinated. Tens of thousands of contact tracers conduct in-depth interviews each day of people who have been exposed to the virus by someone with symptoms or a positive SARS-CoV-2 test result. The call from a contact tracer covers a long list of topics, including if and when the person should get tested or quarantine themselves. For the unvaccinated, it should also include support to get vaccinated immediately.

A call from a contact tracer might be the first time an individual thinks seriously about Covid-19. A close brush with it, which can be disruptive to both life and work, is often a sobering experience. The beginning of the quarantine period is the optimal time to arrange for vaccination, when people are most concerned about their recent exposure and most receptive to advice from contact tracers. Yet CDC guidelines continue to recommend that people seek vaccination after the end of quarantine due to the risk of exposing health care workers.

The vast majority of people potentially exposed to SARS-CoV-2 do not develop Covid-19, yet the same circumstances that lead to one exposure could very well lead to another. Vaccinating someone who has already been exposed might have a higher impact on preventing future transmission than vaccinating others because of network effects — vaccinating highly connected people can cut off more future chains of transmission.

Linking testing and tracing to vaccination might seem obvious, but the reality is that it is not happening nationally. Testing and tracing and vaccination continue to be operationally siloed. Not integrating these activities is a huge lost opportunity to increase vaccination rates in high-risk people. No one should leave a testing facility or get off the phone with a contact tracer without having a serious discussion about getting vaccinated.

Every Covid-19 outbreak is a crisis. But they are also opportunities to identify individuals at greatest risk and protect them from infection. Don’t let these crises go to waste. Lean into them and vaccinate.

K. J. Seung is senior health and policy advisor at Partners In Health, an associate physician at Brigham and Women’s Hospital, and an assistant professor of global health and social medicine at Harvard Medical School. Natalie Dean is an assistant professor of biostatistics and bioinformatics at Emory University’s Rollins School of Public Health.

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