- It’s difficult to compare COVID-19 immunity from natural infection and vaccination, but getting vaccinated is a much safer option.
- There is no data showing that breakthrough infections will boost the degree of immunity provided by COVID-19 vaccines.
- Individuals who had breakthrough cases should still get booster doses if they are recommended for it, experts say.
People who get vaccinated against COVID-19 develop strong protection against severe illness, hospitalization, and death from the disease. But they can still get infected and have what is called a breakthrough case.
Both natural infection and vaccination work at priming your body’s immune response. So, if you get a breakthrough infection will you need a booster shot down the line? Although there is currently no available data on the impact of breakthrough cases on the degree of COVID-19 immunity, experts say you should still get the booster dose if you are recommended for it.
How Do Vaccines Compare to Natural Immunity?
Immunity to COVID-19 can be acquired in two different ways, either through natural infection or vaccination. Both will allow the body’s immune system to produce antibodies that are necessary to fight the disease, but they are not entirely the same.
“Natural immunity confers some short-term protection against infection, but data now clearly shows protection from natural immunity is not as long-lasting as from vaccination,” Amber D’Souza, PhD, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, tells Get Meds Info. “Among those who have had COVID, the risk of getting COVID again is higher among those who did not get vaccinated, than those who got vaccinated.”
A recent Centers for Disease Control and Prevention (CDC) study shows that unvaccinated people who were previously infected are more than twice as likely to get COVID-19 again compared to those who are fully vaccinated. This suggests that vaccine-induced immunity may be greater than natural immunity. Additionally, antibodies acquired from vaccines may be more likely to target new virus variants.
However, Albert Shaw, MD, PhD, Yale Medicine infectious diseases specialist and professor of medicine at Yale School of Medicine, tells Get Meds Info that there is a lot of variation in the immune response from infection to vaccination. It can be difficult to compare the two.
“Factors such as how much virus someone was exposed to and infected with, whether their course of COVID-19 was mild, moderate, or severe, as well as factors such as age and pre-existing medical conditions—which affect the function of the immune system—all play a role,” he adds.
Because of these factors, even the immune response from natural infection alone will not be the same across all individuals. However, with a vaccine, most people are administered the same dose, reducing the variability of the elicited immune response, to some extent.
Compared to vaccination, getting COVID-19 is, by far, the more dangerous option. Unlike a natural infection, vaccines help individuals develop immunity against COVID-19 without causing illness or any resulting complications.
Does a Breakthrough Case Increase Your Immunity?
Although some individuals speculate whether immunity from a breakthrough case would boost the current protection conferred by vaccines, there is no definite answer for this yet.
“A young, healthy fully vaccinated individual could have a breakthrough case and activate their immune system—especially the memory response of the immune system—and possibly have an increased immune response from re-exposure to SARS-CoV-2,” Shaw says. “Or their breakthrough infection could also represent an inadequate immune response to vaccination, which can still happen in healthy individuals.”
Rigorous clinical studies are needed to understand the degree and duration of immunity from both natural infection and vaccines, but keep in mind that breakthrough infections are not recommended as a means to “boost” immunity.
Breakthrough cases are mild about 90% of the time, but the risk of hospitalization or death is still present, according to the American Medical Association.
What This Means For You
If you are fully vaccinated, you still have to practice safety precautions such as mask-wearing and social distancing because you are not 100% immune to COVID-19. Breakthrough infections are not recommended as a method to “boost” your immunity even further, and there is no scientific evidence that they do so.
Do You Still Need a Booster After a Breakthrough Infection?
“We don’t know the answer to this question yet, but my feeling is that if you are in a group for which boosters have been recommended, I’d still get the booster,” Shaw says. “We don’t know how a breakthrough infection compares to a booster vaccine.”
According to the CDC, booster shots are currently available for certain recipients of the Pfizer-BioNTech vaccine and Moderna, which include:
- Older adults and people aged 50 to 64 years old with medical conditions
- Long-term care setting residents aged 18 years old and older
- People with medical conditions aged 18 to 49 years old
- Employees and residents at increased risk for COVID-19 exposure and transmission
Boosters are available for any 18+ recipient of the Johnson & Johnson vaccine, as long as it’s been two months since their initial shot.
“Immunity after a breakthrough case is imperfect,” David Dowdy, MD, PhD, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, tells Get Meds Info. “People who have been infected should wait until after they have gotten better—and they may want to wait even longer after that—but it is suggested that they get a booster, if they are recommended for it.”
Ultimately, many factors have an impact on the degree of immunity that the body develops against infection, and “there is no ‘one-size-fits-all’ immune response to COVID-19,” Shaw says.
The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.