Yes, new research is surprising, but experts urge caution.
Covid cases are rising and new variants without easy-to-pronounce Greek letters are running rampant. With masks once again an encouraged accessory, it’s rational to wonder if Covid will ever be a distant memory. Which begs the question, Are we just supposed to keep getting a Covid shot every single year, forever? Now, a controversial article seems to be legitimizing what anti-vaxxers have been saying for many months: that vaccines could be making people more likely to catch Covid. But is that really the truth? Trying to wade through all the research is enough to make your head spin, so we spoke to an expert to try to make sense of this confusing news.
First off, what’s with the rise in new variants?
One thing’s for sure: The virus is evolving. A study published Dec. 19, 2022 in Nature examining the Omicron variants noted, “Such rapid and simultaneous emergence of multiple variants with 55 enormous growth advantages is unprecedented.” But Dr. René Najera, director of the center for public health at the College of Physicians of Philadelphia, told us that the virus isn’t evolving because more people are vaccinated, but because people are still getting sick with Covid-19.
“The vaccine has influence on the evolution of a virus in that it prevents people who get infected to get the full disease, thus lowering the risk of passing the virus to another person (which leads to slight shifts in the genetics of the virus),” he says. “What does influence the evolution is how many people are getting it and passing it on to others. With so many places around the world without access to vaccines and/or treatment (or without the ability to social distance, like in big cities with high overcrowding), we are seeing this virus mutate quickly.”
Dr. Purvi Parikh, allergist and immunologist with Allergy & Asthma Network, tells Katie Couric Media, “The vaccines reduce transmission and severe disease, thus making newer variants less likely. Whereas not getting vaccinated or not being up to date with the vaccine makes you more likely to get Covid as well as pass it on, and thus cause mutations in the virus each time it is passed from person to person.” According to CDC data, only 17.7 percent of U.S. adults received the bivalent booster, and on top of that, Covid restrictions have been relaxed, with less people masking and distancing and more people traveling and attending indoor gatherings.
Variant XBB.1.5 is currently sweeping the northeast U.S. and is poised to drive up cases in the rest of the country, but we’ll still need to wait to see its impact. As FDA Commissioner Robert Califf said in a tweet, “At this point, we’re experiencing an increase in cases with no evidence of increased severity of illness related to these variants.” In a briefing, Maria Van Kerkhove, technical lead of the World Health Organization’s COVID-19 response, said, “We do expect further waves of infection around the world. But that doesn’t have to translate to further waves of death, because our countermeasures continue to work.” According to data from NBC, hospitalizations, while on an upward trend, are far below what they were at this time last year.
Jesse Bloom, an evolutionary biologist at the Fred Hutchinson Cancer Center in Seattle, told Bloomberg that the XBB.1.5 variant isn’t better at evading immunity than XBB, it’s just mutated to be more transmissible. This, Dr. Najera says, is what viruses do — they evolve to become less deadly and more infectious so they can continue to find a host. “This is a chicken and an egg problem,” he tells Katie Couric Media. “It’s not that more people getting vaccinated is leading to new variants,” he says, “it’s more that billions of people around the world are getting the virus — many of them because vaccines are not available, or because the infrastructure and public health isn’t there to keep them safe. And so they’re getting sick. And that is leading to more variants.”
Does getting more vaccines put you at a bigger risk of catching covid?
The WSJ article — which, it should be noted, is an op-ed — states, “Growing evidence also suggests that repeated vaccinations may make people more susceptible to XBB and could be fueling the virus’s rapid evolution.” While the virus is evolving, the FDA states, “There is no clear or compelling evidence that repeated vaccination with Covid-19 vaccines makes people more susceptible to the XBB, XBB.1 or XBB 1.5 variants.”
This claim — that having more vaccine doses makes you more likely to get Covid — comes in part from a study, which has yet to be peer-reviewed and is pre-publication, from the Cleveland Clinic. The study looked at 51,000 of its employees and examined how many had gotten vaccinated and gotten sick from Covid. It found that, among the employees evaluated, incidence of Covid-19 increased as the number of vaccines increased.
But Dr. Najera cautions that correlation doesn’t equal causation. In other words, just because the risk of Covid-19 increased with the number of vaccines received, doesn’t necessarily mean that more vaccines makes people more susceptible to Covid. There are also a number of confounding (aka complicating) factors in the study. For one, healthcare employees, Dr. Najera points out, are more likely to be required to get vaccinated, so they may be more vaccinated than other populations. On top of that, they’re more likely to be exposed to people with Covid, which would make them more likely to get sick. “You put those two together, and it’s going to seem like people who are highly vaccinated are also going to be at higher risk of getting infected. But both things are related to the nature of their work, and that is a confounder.”
Another reason Dr. Najera urges caution regarding the results of this study is that it doesn’t have a control group of non-healthcare workers, so it can’t really be applied to the general population.
What’s the bottom line?
According to the FDA, “Well-designed clinical trial evidence demonstrated that the updated COVID-19 vaccines given as boosters elicited superior neutralizing antibody response compared to the original (monovalent) boosters.”
It’s also worth adjusting our expectations. Dr. Parikh says getting more vaccines “decreases your susceptibility to not only Covid-19, but also to more severe forms of it.” But, Dr. Najera says, it’s not a guarantee you’ll never come down with Covid — which, he admits, was “a little bit off” with initial messaging regarding the Covid-19 vaccine.
“[Vaccines] aren’t like a magical force field that protects you from viruses landing on you and infecting you,” he says. “They give your immune system a heads-up, so that when you are infected, the response is fast enough that sometimes you won’t get any symptoms. Other times you will, but not as badly. And then in rare instances, yes, you’ll get the full course of the disease.”
But that doesn’t mean that they’re any less vital, says Dr. Najera. “Any vaccine — we see this from the first vaccine against smallpox, to this vaccine — has always been about keeping you alive.”
