If You Got This Vaccine, Your Risk of COVID After Vaccination May Be Higher
New research shows that breakthrough infections appear to be more common after this shot.
From celebrities like Reba McEntire to those vacationing in a Massachusetts beach town, breakthrough COVID infections have hit people across the U.S. over the past few months. And despite data showing that getting a post-vaccination case of COVID is still uncommon, it has become a significant concern amid the country's continued fight against the virus. Studies have shown that anything from age to prior health conditions to emerging variants could cause you to have a weakened immune response to the vaccine, which would heighten your chances of a breakthrough infection. But your risk of getting COVID after vaccination may also be higher depending on which vaccine you got.
According to the Centers for Disease Control and Prevention (CDC), breakthrough cases can occur with any of the three vaccines. "No vaccines are 100 percent effective at preventing illness in vaccinated people. There will be a small percentage of fully vaccinated people who still get sick, are hospitalized, or die from COVID-19," the agency explains.
The CDC was collecting data on all breakthrough infections at one point but has since transitioned to just monitoring severe post-vaccination cases. Now, the responsibility of reporting all breakthrough cases falls on states, and of the 25 states that do report them, most don't provide information on the number of cases associated with each vaccine, Live Science explained. However, the science news outlet recently collected data from Oklahoma and Washington, D.C., which do categorize by vaccine.
According to Live Science, Johnson & Johnson showed the highest rate of post-vaccination COVID cases in both populations. In D.C., nearly 151,000 people received two doses of Pfizer, 124,700 received two doses of Moderna, and 24,000 received Johnson & Johnson, per data from D.C. Health. Of those people, 0.32 percent of Johnson & Johnson recipients had breakthrough infections compared to only 0.2 percent and 0.13 percent of Pfizer and Moderna recipients, respectively.
A similar pattern occurred in Oklahoma. According to the Oklahoma State Department of Health, around 817,000 people had gotten Pfizer, 674,000 received Moderna, and 102,000 got Johnson & Johnson. When it came to breakthrough infections, 0.21 percent of Johnson & Johnson recipients tested positive for COVID after vaccination, while only 0.17 percent of Pfizer recipients and 0.12 percent of Moderna recipients tested positive.
Johnson & Johnson's one-dose vaccine showed lower efficacy against symptomatic infection during clinical trials, so it's not unexpected for more breakthrough infections to occur with this particular shot. But Robert Darnell, MD, a physician scientist at the Rockefeller University in New York, told National Geographic that it's still too early and there is still too little data to say for certain if breakthrough infections in real-world cases are more likely with a particular vaccine.
"We need more science," Darnell explained, especially amid the rise of the Delta variant. A recent Mayo Clinic study pre-published Aug. 8 on medRxiv has suggested that Moderna's vaccine is more protective against the variant than Pfizer's. The effectiveness of Moderna fell to 76 percent during Delta's dominance, but Pfizer's fell to 42 percent.
However, the researchers for this study note that these statistics show that both vaccines are still protective, even against the latest COVID variant. Studies aimed at Johnson & Johnson indicate that this vaccine is also still protective against the Delta variant.
"We're still seeing that infection is absolutely higher among unvaccinated persons and lower among vaccinated persons. It's just not zero," Stacey Rose, MD, an infectious disease physician at Baylor College of Medicine in Houston, Texas, told National Geographic. "What I don't want is for … breakthrough infections to make people think, 'Oh, well, then forget [getting vaccinated].' Your risk of getting the disease is still lower [if you're vaccinated], even with the Delta variant."