As the race to create COVID-19 vaccines rages on, with two candidates likely coming to market this month, it’s it’s worth taking a moment to recognize that despite all the apparent successes, there’s still a lot we don’t know about how these vaccines will work. Case in point: the CEO of Pfizer, which produced a vaccine that’s said to be more than 90 percent effective, says the company doesn’t yet know whether people who’ve been vaccinated can still carry the virus, potentially spreading it to others.
Pfizer CEO Albert Bourla appeared on “Dateline NBC”Thursday night, alongside the CEOs of Moderna and Johnson & Johnson, whose companies are also working on vaccines. The three participated in a joint interview to lay out the challenges ahead—including distributing potentially billions of vaccine doses to people around the world. That’s no simple logistics problem, though the companies seem confident it can be solved.
Yet there are more fundamental questions about the post-vaccine future, including whether people who’ve been vaccinated may be able to spread the virus to others. “I think this is something that needs to be examined,” Bourla told Dateline. “We are not certain about that right now.”
That particular aspect hasn’t been studied yet. “There is a theoretical risk that you could pass the virus on to others despite being vaccinated,” says Kirsten Hokeness, Ph.D., director of Bryant University’s new Center for Health and Behavioral Sciences. And we definitely need more answers before people stop wearing masks.
But virus transmission by vaccinated people hopefully won’t be the case. “The goal of the vaccine is to create immunological memory in the body so that when you encounter the virus in the future, your immune system rapidly ramps up and attacks the virus very quickly before you get sick. Therefore, as long as the vaccine boasts a strong immunological response, it is likely that the virus will be stopped from replicating in your system pretty quickly,” Dr. Hokeness says. That would limit your ability to spread it to others. “It can happen, but the risks would be far less than if you were not vaccinated,” she says, adding that “since the vaccine requires a booster it may be that your ability to spread the virus would be greater if you only got one dose, but there is not data available yet that would suggest that that is the case.
Bourla’s comment underscores that while vaccines are a vital tool in combating the pandemic, having them doesn’t mean everyone can safely return to “normal” right away. For starters, it’s going to take time to get everyone vaccinated. And there are other questions that don’t have answers yet, including exactly how long post-vaccination immunity would last. So in the meantime, stay safe and wear a mask.