All this talk about the highly contagious Delta variant has some D.C. residents feeling anxious even if they are fully vaccinated against COVID-19. Those who got the one-shot Johnson & Johnson vaccine, in particular, are wondering whether they’ll need to get a booster of the Pfizer or Moderna vaccines. 

To back up, the Delta variant was first detected in India and officially named B.1.617.2. Cases of the Delta variant have already been reported in the United States, and Dr. Anthony Fauci of the National Institute for Allergy and Infectious Diseases says the variant of concern makes up 20 percent of newly reported cases nationwide. The CDC predicts the Delta variant will be the predominant lineage in some regions. Currently, the variant first detected in the United Kingdom, dubbed the B.1.1.7, is the dominant variant in the D.C. region, according to the Centers for Disease Control and Prevention. Studies to date suggest the Delta variant is upwards of 60 percent more transmissible than the one first identified in the U.K—and that variant was already a lot more transmissible than the original coronavirus. 

While some public health experts say boosters may be necessary as the Delta variant spreads—with a few already getting a booster themselves—the D.C. health department is not ready to make that recommendation. DC Health says at this time there is no need to get additional vaccinations after receiving the J&J vaccine. “There is still much to be learned about the impact of the COVID-19 variants, but at this time the evidence supports that any of the available vaccines protect against the variants,” says Dr. Kimberly Sommers, an ​infectious disease physician with DC Health’s COVID-19 Emergency Response. “At present, there isn’t evidence that additional protection is gained by getting more than one vaccine product and this is not recommended.” 

It’s unlikely that D.C. would get ahead of federal guidance. Currently, the CDC has not released any recommendations on boosters, generally speaking. The CDC’s panel of experts, the Advisory Committee on Immunization Practices, has yet to develop recommendations. In a recent podcast interview, CDC Director Rochelle Walensky said there is no official recommendation yet because there is insufficient data. “We don’t have a huge amount of data on the safety and the side effect profile of getting a mRNA vaccine [meaning the Pfizer or Moderna vaccines] after the Johnson & Johnson, or really the effectiveness of that approach,” she told host Andy Slavitt, the former White House advisor for COVID-19 response. “It’s probably safe because these vaccines are generally safe to begin with, but there aren’t any data to inform this one way or another.” 

But what if someone wanted to get a second shot of an mRNA vaccine because they are very anxious about the Delta variant? Would it be a huge mistake to do so, Slavitt asked. Walensky signaled it wouldn’t be a mistake, at least not based on what she knows so far. “Some decisions feel obvious, like ‘Should I get vaccinated in the first place?’ Or … if ‘I have one vaccine, should I get a second?’” added Slavitt. “Some decisions, there is quite a lot of data. Other decisions are really a matter of personal judgement.”

The data that does exist and has people interested in boosters has to do with the efficacy of the Pfizer and AstraZeneca vaccines. (AstraZeneca is not yet approved for use in the U.S. but is made in a similar way to the J&J vaccine.) According to a Public Health England study published in late May, the Pfizer vaccine was 88 percent effective against symptomatic disease from the Delta variant two weeks after the second dose, while the AstraZeneca vaccine was 60 percent effective. Both vaccines were 33 percent effective against symptomatic disease from the Delta variant three weeks after the first dose. From this, public health experts have come to believe the second dose is very important to secure the strongest protection against variants. 

Other studies out of the U.K., published in mid-June, also suggest that the Pfizer and AstraZeneca vaccines are less effective at preventing symptomatic disease from the Delta variant after just one dose. A second study not certified by peer review by Public Health England found Pfizer and AstraZeneca vaccines are highly effective against hospitalization caused by the Delta variant: 96 percent and 92 percent, respectively. A single dose of the AstraZeneca vaccine was still 71 percent effective against hospitalization caused by the Delta variant. A single dose of Pfizer was 94 percent effective. 

Public health experts say the important thing to remember is that neither Pfizer nor AstraZeneca is authorized or approved as a single dose. J&J, on the other hand, is approved as a one-dose vaccine. “One could speculate anyway that we would see something similar with the J&J vaccine,” says William Moss, executive director of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health. “We just don’t know.” 

To be clear, all the vaccines approved in the U.S. show extraordinary promise against the B.1.1.7 variant, or the one first detected in the UK. It is evidently clear that unvaccinated people are in more danger because of the variants. 

People interested in getting a booster of Pfizer or Moderna after they got a J&J vaccine are likely considering this because some European countries are mixing vaccines. “For example, I know that in Germany, if you start with AstraZeneca, they will permit you—indeed, sometimes even encourage you—to get your second dose of Pfizer. How do I know this? I know it because my son lives in Berlin and that’s what he did,” says William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center and a CDC consultant. “Now, that’s not exactly the same as what is happening here, but it’s pretty similar. And what one would hope is that there are some European investigators who are actually studying this a little bit in a systematic fashion. They could provide us with their information and that might provide some basis for the CDC’s advisory committee to consider this.”

The National Institutes of Health did start a clinical trial earlier this month in which adult volunteers who’ve been fully vaccinated will receive booster doses of different vaccines. The goal is to study the mixing and matching of vaccines. The New York Times reports the clinical trial will start delivering results in a matter of weeks because investigators want to share what data they have collected with policymakers in the event of a surge in variants this winter. Given that data and recommendations are likely forthcoming, some public health experts say it would be OK to wait on getting a booster. 

“All of this is just kind of weighing risks and benefits,” says Moss. “For someone who got a J&J vaccine, who’s living in a community with high vaccine coverage and low case counts, I think it would be prudent for that person, such a person, to wait until we either have more evidence on the efficacy of a single dose J&J and/or recommendations from the CDC and ACIP on a booster dose.”

“For a person who received a single dose J&J, who’s living in a community where vaccination coverage is low and where the case counts are going up—and particularly with a Delta variant,” he continues, “I think it would be not unreasonable, despite the lack of a guide of evidence and recommendations for such a person to get a booster dose with an mRNA vaccine … I can understand why some of the infectious disease experts have made the decision to do so.” 

In D.C., vaccine coverage is high and coronavirus transmission is low. According to the CDC, 62.3 percent of the adult population in D.C. is fully vaccinated, as of June 30. (52.2 percent of the entire population is fully vaccinated.) D.C. met the White House goal of 70 percent of its adults being partially vaccinated earlier this month, and has a high adherence rate to the second dose. COVID-19 cases, hospitalizations, and deaths have dramatically dropped as more and more residents got vaccinated. DC Health has not reported a single death related to COVID-19 since June 18. As of June 29, the daily case rate stands at 1.7 per 100,000 people, according to DC Health.  

Even if D.C. residents want to get a booster, they might have trouble finding a provider who’ll administer one. That’s because local vaccine providers are also waiting on recommendations before offering guidance to patients or administering booster shots. “We are waiting for CDC recommendations,” says a spokesperson for MedStar Health. Dr. Michael Kim, president of Grubb’s Care Pharmacy, says they’ve received one question about boosters but await more guidance on the subject. 

Dr. Randi Abramson, the medical director for Bread for the City, says she hasn’t received inquiries from patients about boosters. But if people asked for one, Abramson says her community health center would not administer one. Vaccine providers can see in their system whether someone has already gotten vaccinated, she says. “We are following guidelines. We are following the data,” Abramson says. “So should people be getting boosters at this point? No. Let’s just wait till we know more information so that we’re smart about this.” 

Abramson says there may be a point where the CDC says people need boosters. She encourages people to keep an open mind because it’s not indecision that’s preventing experts from recommending boosters at this point. “This is how public health works. This is how the virus works. And we have to just continue to be kind of open to know what’s the latest information. And then let’s pivot.”

If D.C. residents are still concerned about the Delta variant, public health experts encourage individuals to practice data-driven public health measures, like masking. Mask in crowded, public indoor spaces, they say. DC Health does not have plans at the moment to update masks guidance as Los Angeles just did. “We are aligned with CDC recommendations that fully vaccinated people are effectively protected from COVID-19 including the variants and fully vaccinated people do not need to wear masks in most settings,” a spokesperson says via email. “Unvaccinated people should continue taking precautions until they are able to or choose to be vaccinated. These recommendations highlight the importance of getting vaccinated: to protect yourself and those who can’t get vaccinated.”