And now the number of people experiencing COVID-19 more than once is growing. Hugh Jackman, Drake, Kourtney Kardashian, and Jimmy Kimmel are just a few of the many who have contracted the virus twice. In fact, with the highly infectious omicron variant in circulation, it’s becoming less unusual to have COVID-19 three times — or even four.
How Common Are COVID-19 Reinfections?
While the Centers for Disease Control and Prevention (CDC) is still collecting and analyzing data on reinfections, some states have presented figures that give some idea of the scope of the issue. A chart from New York State shows that six million New Yorkers contracted COVID-19 for the first time from January 2021 to September 2022, plus 393,000 cases of people who got repeat cases of COVID-19. That suggests that just over 6 percent of total cases were reinfections. At the end of September, the Department of Health in Hawaii reported that the percentage of COVID-19 cases involving individuals who had a prior infection has grown to about 10 percent of new confirmed cases. “The data on reinfections underscores what we have been saying; that limited immunity from previous infection only lasts so long. Regardless of whether a person has had COVID-19 in the past, they should stay up to date on their vaccinations and boosters to get increased protection from severe illness and hospitalization,” said Hawaii State epidemiologist Sarah Kemble, MD, in a statement.
New Omicron Subvariants May Be Driving More Reinfections
Since COVID-19 first appeared around three years ago, the virus has been evolving. Omicron has proven to be an efficient spreader of the disease, with the BA.5 and BA.4 subvariants especially good at evading protection provided by vaccines and previous infection. “The bad news is these omicron subvariants are causing the majority of reinfections,” says Dean Winslow, MD, professor of medicine at Stanford University in California. “But the good news is, it does appear that the omicron variants are less virulent [meaning they are less likely to cause severe disease] than the original Wuhan strain or the delta variant.” Around 6 in 10 cases in the United States are currently due to BA.5, according to the CDC, with BA.4.6 (a sublineage of BA.4) accounting for more than 11 percent of infections. Other, newer variants are gaining ground. Over the week ending October 22, two new variants jumped to the forefront, BQ.1 and BQ.1.1, which now make up about 17 percent of cases. The BF.7 subvariant jumped from 5.3 percent of U.S. cases to 6.7 percent in a week, while BA.2.75 and BA.2.75.2 climbed from 2.7 percent of new infections to 2.9 percent. While research on these mutations is preliminary, early data posted to bioRxiv suggests that BA.2.75 may be highly capable of evading antibodies from prior COVID-19 infection. Another investigation published October 19 in The New England Journal of Medicine suggested that BA.4.6 could drive reinfections.
How Well Do Vaccines Ward Off COVID-19?
Back in late 2021 and early 2022, as omicron took over from the delta variant, it became clear that existing vaccines were less effective than they had been at keeping people from getting infected. An ABC News analysis of data collected by the CDC found that between April 2021 and April 2022, so-called breakthrough cases grew from 3 percent of new COVID-19 infections to more than 60 percent. Although boosters initially bumped up protection against all infections, a CDC study published in 2022 discovered that their ability to ward off mild or moderate illness began to wane after four months. “Despite vaccine limitations, people still need to understand how good they are,” says William Schaffner, MD, an infectious disease specialist and professor of preventive medicine and health policy at the Vanderbilt University School of Medicine in Nashville, Tennessee. “Vaccines are exceedingly effective in preventing severe disease. They’re designed to keep you out of the hospital and the intensive care unit, and keep you from dying.”
Can the Updated Bivalent Boosters Help Prevent Infection and Reinfection?
When omicron came on the scene late last year, readily infecting even immunized people, federal health officials urged vaccine makers to retool their shots and come up with a formula that would target this new variant. By September 1, both the U.S. Food and Drug Administration and the CDC had green-lighted updated boosters from Pfizer and Moderna. The new bivalent boosters target BA.4 and BA.5 by including components of the virus’s so-called spike protein to the existing vaccine composition. “The updated COVID-19 boosters are formulated to better protect against the most recently circulating COVID-19 variant. They can help restore protection that has waned since previous vaccination and were designed to provide broader protection against newer variants,” said Rochelle Walensky, MD, MPH, director of the CDC, in a statement. Preliminary evidence suggests that the bivalent vaccines offer more powerful protection than earlier formulations. Infectious disease experts say it’s still too early to predict how well the boosters will perform in the real world. “We just don’t have robust enough data yet just because so few people have been vaccinated [with the updated booster],” says Dr. Winslow. Winslow adds that he wouldn’t be surprised if we begin to treat COVID-19 like the flu — as scientists identify new variants, vaccine makers adjust their formulas each year to match. “It’s like playing whack-a-mole with this virus,” says Winslow. “New variants keep popping up and we’ll need to come up with ways to hit them down.”
Is Reinfection Good or Bad for You?
The CDC says that people who recover from COVID-19 retain antibodies that offer some protection against reinfection. But the consequences of repeat infections may lead to unexpected health troubles down the road. A preliminary study from Washington University in St. Louis looked at the health records of more than 5.4 million Veterans Administration patients. The researchers found that those who had COVID-19 more than once had double the odds of having or dying from a heart attack compared with those who’d had COVID-19 just once. Lung, kidney, and gastrointestinal health risks were also greater among the reinfected. The researchers identified patients with a first infection between March 2020 and September 2022, following them until April 2022. Just over a quarter-million had COVID-19 just the one time during that period, while more than 36,000 had two infections, over 2,200 had three infections, and 246 had four or more infections. The study authors noted that negative health outcomes were lowest in people with one infection, increased in people with two infections, and were highest in people with three or more infections.
Does Reinfection Raise Long COVID Risk?
While there is concern that reinfections may raise the risk of long COVID or make symptoms of long COVID worse, Dr. Schaffner says, “In regards to reinfection, we have so many variables out there that I won’t say what the implications for long COVID are. I think we don’t know at this stage. The updated vaccines should reduce your chances of getting reinfected, but the bottom line is getting vaccinated will help keep you out of the hospital and [protect you] from getting severely ill.” He adds that as reinfections rise, standard precautions such as masking up indoors in public spaces and testing before group gatherings can help reduce risks and are especially important for events that include people who are vulnerable to severe COVID-19, such as seniors and those with heart disease.
