I was next, experiencing my first COVID-19 symptoms the morning of Christmas Eve. Since both my husband and I were vaccinated and boosted, we felt blindsided. My husband rebounded fairly quickly, but I languished for nearly two weeks and didn’t feel quite like myself for a solid month. (I blame my asthma.) As I recovered, I came across a study that suggested there may be a silver lining to this wretched experience: so-called super immunity, also known as hybrid immunity, attainable through a combination of vaccination and infection. The study, published in JAMA in December 2021, looked at immunized healthcare workers who developed breakthrough COVID-19. The researchers found that two doses of a vaccine plus the breakthrough infection produced what they described as a “really robust” immune response. Specifically, total levels of immunoglobulins (antibodies) more than tripled. I began to wonder: Had I become a COVID-19 superwoman, overflowing with antibodies and impervious to the threat of the coronavirus, at least temporarily? I’m cautious by nature, and wasn’t about to plunge into full-on socializing during the omicron surge even with my trusty N95 mask on. But I was eager for answers to a few questions. Did super immunity really exist? If so, did I have it and how long would it last? Most important, what might my immune status mean for my life in the weeks and months to come?
Super Immunity, Explained
To learn more about super immunity, I called Bill Messer, MD, PhD, an associate professor of molecular microbiology and immunology and infectious diseases at Oregon Health and Science University (OHSU) in Portland. When I asked Dr. Messer to explain what “super immunity” means, he started with a refresher on what vaccines do, which is teach the immune system to recognize a virus. “Vaccines enable us to develop antibodies and immune cells that remember the virus if we’re exposed to it,” he told me. Messer called a breakthrough infection a “learning opportunity” for the immune system. (Now there’s a positive spin!) “The immune system takes lessons from the vaccine, applies those lessons to dealing with the infection, then acquires additional knowledge from the breakthrough infection,” he said. Messer told me that the more severe the infection, the more the immune system may learn from it. “If someone has very mild symptoms, the immune system may not get as good a lesson as it would if symptoms were more severe or lasted longer,” he said. Ultimately, the amount of protection you get from vaccination plus breakthrough infection may be greater than the sum of its parts. “The combination gives our immune system a greater capacity to recognize the viruses that cause COVID-19, apart from what it learns from one or the other mode in isolation,” said Messer.
The Omicron Effect
The December JAMA study was conducted when the delta variant was predominant, which made me wonder whether an omicron infection would also result in super immunity. Omicron, as we know now, is different from delta, the variant it displaced. Because it is so highly mutated, it is uniquely relentless in how quickly it spreads and how well it evades the immune system’s defenses. Andy Pekosz, PhD, a virologist at the Johns Hopkins Bloomberg School of Public Health in Baltimore, assured me that super immunity exists with omicron as well as with delta. “It’s clear from the data that after getting the mRNA [Moderna and Pfizer] vaccines plus a breakthrough COVID infection, you end up with more antibodies that can ‘cross react’ with different variants,” Dr. Pekosz told me.
Could It Actually Be Good to Get COVID-19?
Hearing all this, I wondered if it would be smart for vaccinated and boosted people to try to get COVID-19 (or at least not avoid it like … the plague). “We definitely don’t recommend this,” said Bettina Fries, MD, the chief of the division of infectious diseases and a professor of medicine at Stony Brook University’s Renaissance School of Medicine in Stony Brook, New York. “There is a small percentage of people who don’t generate a good immune response for reasons we can’t account for, and we don’t know who they are.” Dr. Fries also reminded me that a person’s immune response to a COVID-19 infection or vaccine varies depending on how old they are, whether they have underlying medical conditions, and whether they are taking immune-suppressing medications or are otherwise immune-compromised. “Seventy-five percent of deaths from COVID occur in people 70 and older,” she said. “And, as we all know by now, people with comorbidities like diabetes or heart or lung disease, or who are immunocompromised, should be careful regardless.” All the experts also cautioned against forgoing vaccines and relying on the “natural immunity” conferred by a previous COVID-19 infection. An infection alone does not super immunity make; that only comes from vaccination plus infection. “Even if you have been infected with COVID, if you’re not vaccinated, well, all bets are off,” warned Fries. As a vaccinated and boosted person, Fries said she is “not in a panic” about getting COVID-19 herself, but would be mindful of the risk of infecting others who may be more vulnerable to severe disease. “If my kids were to get it, I’d take care of them and likely get it, too. But I wouldn’t then go and visit my 90-year-old mother,” she said. Pekosz reminded me that if people do get infected with omicron or another variant they can pass it on to someone else before they’re symptomatic — “and you don’t want to be responsible for that.”
How Long Does Super Immunity Last?
Before I got too excited about my super immunity, I wanted to know how long my extra protection would last. Messer was the most optimistic of the experts I spoke with; he was willing to estimate three to six months, though he hastened to add, “No promises! I’m generalizing based on what we see with other kinds of immune responses.” He explained, “Even when antibodies drop off, you will still be left with ‘memory’ immune cells [also known as T cells] related to the infection or vaccine. Those are likely poised to reactivate should you get infected again, so that’s a good backstop.” The other experts gave me a mere three months of superwoman time. Worse, Pekosz told me that anyone older than 55 (a category that includes me and my husband) should be extra careful, super immune or not. He added that everyone needs to be more careful than in the before times, particularly anyone who lives in areas where infection rates are high or going up. “I think, if you’re vaccinated and boosted, you can go back to normal life — to a point,” he said. “If you want to go out to dinner, do it, but it’s better to avoid crowded restaurants. And my wife and I are going to the movies tomorrow, but we’re going at a time when it won’t be crowded.” That sounded reasonable to me, though if the last two years have taught us anything, it’s that people have vastly different ideas about what sounds reasonable and what seems risky.
Vaccination Remains Vital
Whatever your risk tolerance, there are some bottom-line scientific truths essential for keeping everyone safe: “We all need to work together and get vaccinated and boosted, because we can’t safely enjoy life when infection rates are high,” said Fries. She also believes that COVID-19 is here to stay. “It will keep coming back, and keep on changing, just like the flu. And we will continue to get updated vaccinations, just like with the flu.” “When the vaccines first rolled out, the aim was to get people strong immunity as fast as possible to turn the tide on the pandemic,” Pekosz told me. “Now that we know COVID will likely be with us forever, we need to come up with a strategy for long-term immunity, where we’re maybe getting boosted every two or three years depending on how severe the disease is.” Pekosz believes there is reason to be hopeful: “I think the mRNA vaccines have great potential for long-term protection.”
Life After a Breakthrough Infection
Whatever my super immunity timeline (and no one really knows for sure), I’m using these days and weeks after my triple vaccination and infection to allow myself to feel a bit more free: sharing dinners with friends in (uncrowded) restaurants, going to the theater in cities where vaccination is required for entry, and booking a long-delayed trip to Rome, my favorite travel destination. As for what comes after, I’m not going to think about that just yet. Instead, I’m going to savor life, knowing that my time to enjoy it is limited, a truth I’d probably do well to remember even when the pandemic is over.
