Think getting a COVID-19 vaccine means you can abandon the face covering? Not quite

When health care workers began getting vaccinated against COVID-19, it felt like Christmas morning, Dr. Shephali Wulff remembers. “People were having their pictures taken, taking video so they could post it and send it to their parents,” says Wulff, the medical director for infectious disease for SSM Health. “People were fist-bumping. This was the happiest I’d seen them since March.” But amid the celebration, a question popped up—and kept popping up: Do we need to keep wearing PPE? “People ask that question because they don’t understand what the vaccine is going to do for them,” Wulff says.  

If you read a headline like “Moderna’s coronavirus vaccine found to be nearly 95 percent effective,” the fantasies start forming. You imagine walking down the street, shot arm sore but mood lifted. You rip off the mask. You hug a stranger. But not so fast: Phase III trials have shown that COVID-19 vaccines are remarkably good at preventing symptomatic illness and severe disease, but we still don’t know whether they keep people from contracting and spreading the virus.

The nose might hold the answer. That’s what researchers are thinking about, anyway. The virus could hide out in there or in your throat. It would be harder for your cells that have been trained to fight the infection to reach the virus perched atop the mucous membranes. But the virus could also be launched back out into the world by a sneeze or a cough, infecting others who have yet to be vaccinated or can’t mount a good immune response.

Study Group

In addition to following phase III vaccine trial participants for two years, Hoft’s lab will study ways to prompt better B- and T-cell response to COVID-19.

With Operation Warp Speed, the United States’ program to accelerate COVID-19 vaccine development, researchers were aiming for a safe vaccine that would protect people from getting severe illness. So far, Pfizer and BioNTech’s vaccine has been shown to be 95 percent effective; Moderna’s is 94.5 percent effective. That they nailed it on the first try, says Dr. Daniel Hoft, was a “dream.” Hoft is the director of SLU’s Center for Vaccine Development and principal investigator for its Vaccine and Treatment Evaluation Unit. SLU participated in a phase III trial of the Moderna vaccine. To determine whether the vaccinated could pass on the virus, his team would have had to routinely check out the nostrils of trial participants. What they did was already a huge undertaking. “To swab everybody’s nose every week, even if they don’t have any symptoms, would be a much bigger workload that would have slowed us down in terms of trying to get at least the initial efficacy data,” he explains.

To determine whether it’s possible for a vaccinated person to spread the virus, a specific study would be needed, looking at a large number of people who were vaccinated but infected versus those who hadn’t been vaccinated and were infected, and how many secondary infections occurred.

And even if some received vaccines, their likelihood of infection could change on the basis of exposure. “You’ve heard about the superspreaders, right?” Hoft asks, referring to those with high viral loads who spread the virus in aerosolized particles in enclosed spaces. “If you’re exposed to somebody who is blowing a lot more virus in your face, that can overcome immune responses.”

So it’s going to be a while until we can take off our masks. (And in the scenario Hoft describes, why would you want to?) But if that’s disheartening, Wulff has some encouragement: Things should start to look better once herd immunity is achieved. “I think there are reasons to think that the vaccine will affect transmissibility, but we don’t have that data yet,” she says. “Until we do, I would want everyone to keep using the PPE, wearing their masks, social distancing, knowing that things will get better in the next six months.”

MORE TO KNOW

Beyond the Pandemic

RESEARCHERS ARE WORKING TO PREVENT OTHER POTENTIAL OUTBREAKS.

The COVID-19 vaccine is still a high priority for Hoft’s lab, but the team’s started to pick up work paused during the pandemic. Here, three important areas of research.

TUBERCULOSIS VACCINES

TB is the top infectious killer worldwide, according to the World Health Organization—in 2018 alone, 1.5 million people died of it. “Because health programs and facilities were closed or diverted to focusing on COVID, there are going to be setbacks,” Hoft says, “but we’re getting back to trying to understand how we can make better vaccines for TB.”

UNIVERSAL INFLUENZA VACCINES

Researchers have been bracing for an avian influenza pandemic. These bird flus—which kill about 40 percent of those infected with them—mostly occur in Asia. The virus has been able to jump from animal to human but not yet from human to human. We’re not ready to think about the potential of these guys yet, but Hoft’s team is working on developing a universal vaccine against them.

NEXT-GEN COVID-19 VACCINES

Although they don’t quite have Operation Warp Speed funding for this one, the third piece of research Hoft’s lab is conducting concerns a second-generation COVID vaccine. Specifically, they’re looking at T-cell response. “A T cell patrols the body and can actually identify infected cells and destroy them,” Hoft says. “That’s another important protective immune response that we can harness with vaccines.”