How the Delta Variant Is Changing the Public-Health Playbook

In the past few weeks, the U.S. has seen a dramatic increase in coronavirus cases and hospitalizations, the vast majority of them caused by the Delta variant—a mutation of the virus that the Centers for Disease Control and Prevention says is far more transmissible than the original strain. The spike in hospitalizations and severe illness has prompted an encouraging rise in immunizations, particularly in states with low vaccination rates. Still, the U.S. is trailing the European Union in vaccinations, and many Americans, especially white evangelicals and people under seventy-five, remain reluctant to receive the shot.

I recently spoke by phone with Rebecca Weintraub, an assistant professor at Harvard Medical School and the director of the Better Evidence program at Ariadne Labs. Since the pandemic began, Weintraub, who is also a practicing internist, has been working with health officials across the country and around the world, advising them on vaccination efforts. For the past few months, she has been administering shots—and answering questions from skeptical patients—at Brigham and Women’s Hospital and at mobile vaccination sites in Massachusetts. During our conversations, which have been edited for length and clarity, we discussed the best ways to talk to people who lack confidence in the vaccine, the necessity of various forms of vaccine mandates, and why the spread of the Delta variant has forced public-health officials to adopt new messaging.

How would you assess the vaccine campaigns in the U.S. over the past several months?

We knew, like with every other pandemic, that when the vaccines were initially approved we’d be facing vaccine scarcity. This is not a new problem in society. What was new in this moment in many ways was that there was a window for thinking about equitable distribution of a COVID-19 vaccine, and the deployment could be done in a way that could benefit those who are at highest risk of deaths and severe disease. That plan, deployed in early December, was one in which the federal government got heavily involved. And that deployment and that perspective was relatively well received.

What did not happen was a predictable supply to the jurisdictions. So the sixty-four jurisdictions [fifty states, six metropolitan areas, and eight U.S. territories or freely associated states] assumed they would receive, and were told they would receive, certain numbers of doses, and they did not receive that allocation week by week. So you began seeing this second phase of stockpiling so the states could then have that second dose to deploy.

But now obviously we’re in quite a different phase, with sufficient supply. And we have a better understanding of the storage capacity of, for example, the mRNA vaccines, which can be stored in a regular refrigerator for a month—which means we can deploy them in many different types of settings. Most providers have access to a refrigerator, but we haven’t fixed many of the gaps.

What specifically are the types of problems you are seeing?

Early on in the pandemic, we sent the vaccines to health systems, and directly to nursing facilities via retail pharmacies, and then in January and February jurisdictions began deploying the vaccine to additional outlets and different distribution sites. Now there are tens of thousands of distribution sites for the vaccine.

What we’ve been able to show, though, is that there are persistent vaccine deserts—areas of the country where someone needs to drive, walk, or use public transportation for at least fifteen minutes. One reason for that is that most primary-care providers were not equipped to receive the vaccine. They have not been integrated within the deployment. And, when we look at the survey data for primary-care physicians and specialists, they are interested and eager. They want to engage in a conversation with their patients, and then be able to offer the vaccine immediately, so it’s on the menu at all times during the patient encounter.

What you’re saying is interesting to me because all the stories we read about people who are not vaccinated present it as a demand issue, not a supply issue. Even if it is mostly a demand issue, it seems like you’re saying there are also supply issues that could be improved. It’s not just people not wanting to take the vaccine.

That’s correct. We need to be managing and having robust systems for the flow of the product, the flow of information, and the flow of the financing. And we’ve had a bumpy start to all three of those things. We’re concerned about second-dose administration, for example, and then obviously the financing—how to insure that providers are being reimbursed for the time they’re spending on the conversations they’re having and the administration of the vaccine.

What have been some of the issues with second doses?

Let’s say you’re returning to see your primary-care provider or a specialist. They should be able to offer you the second dose as you’re seeing them in an instant clinic. Or say you’re in the midst of a hospital stay—you could receive the second dose there, and not need to go back to the vaccine site. We’re trying to remind everyone that this should be an essential part of your routine. This vaccine should be offered in all settings, and it’s taken quite some time to expand not only the number of sites but, obviously, to integrate this within health systems and health-care delivery.

What have you learned in your work about the different ways to get people to take the vaccine? Are there certain strategies that you think should be used or should not be used?

In conversations with folks at vaccination sites, all the questions that I’m being asked are good questions. People want to understand immunology. They want to understand how a vaccine is developed, how it’s manufactured, how it’s stored in a vial, what type of syringe I am using. People are asking excellent questions about the safety and efficacy of the vaccine. And they also want to talk about the stressors of the pandemic. And I found that, in all the conversations, people are also looking for a bridge toward wellness, and the vaccine’s just the beginning. It’s not the sole intervention to get back to wellness.

Do you think that that conversation should be different with Delta?

Yes. I think at this stage in the pandemic we have to acknowledge that the Delta variant is different. The variants are behaving like they’re in some type of relay race, in which one loses steam and another one takes over. And what we know today, and why we need to convince people and understand their concerns and questions about the vaccine, is that the Delta variant has a different playbook. Its incubation period is about four days, rather than six. And, when people originally were spreading the coronavirus, they were spreading it to two or three people. Now the folks who are infected with the Delta variant are infecting between five and nine people. The reason we’re very conscious of the speed and the acceleration and progress of vaccinations is that the Delta variant has caused the vast majority of the new infections in the United States. This means there has to be a new message, and we need to think about how we’re communicating.