Natural immunity will not protect you against COVID-19 as well as an mRNA vaccine, according to both experts and the research.
Multiple anti-vaccine groups touted natural immunity as a viable alternative to getting vaccinated, but experts say the natural immunity is unreliable — especially when there’s a safe and effective vaccine out there.
Even if you’ve already had COVID, you should still get vaccinated, doctors say.
“The idea of natural immunity, people are kind of taking that and running with it, thinking, ‘I don’t need to get vaccinated.’ That’s not true, either,” said Dr. Sumon Chakrabarti.
“Natural immunity does certainly protect you, but we don’t know to what extent.”
Vaccines, on the other hand, offer consistent protection against COVID-19 — and unlike natural immunity, you don’t have to get sick to gain the protective benefits of a vaccine.
What is natural immunity?
When you get sick and, eventually, beat a virus, your body learns about the virus that made you sick — so you can ideally avoid being infected again in the future.
“Our immune systems have evolved over millions and millions of years to provide us with lasting immunity from infections that we encounter early in life,” said Dr. Matthew Miller, assistant dean at McMaster University’s department of biochemistry and biomedical sciences.
When Canadians caught COVID-19, the same thing happened — to a point.
Provided they survive the illness, patients generally emerge with some protection against COVID-19. That’s why Chakrabarti said there is indeed a “nugget of truth” to the idea that natural immunity can help keep people a bit safer from the virus.
But the level of protection Canadians can get from catching COVID is inconsistent.
“There’s a huge amount of variability in the strength of immunity that’s conferred by natural infection,” said Miller.
“We know, for example, that people who have very mild or asymptomatic cases have much lower levels of immunity than people who have had more symptomatic or severe infections.”
By contrast, the mRNA vaccines offer a high level of protection against severe outcomes from COVID-19 — and they do it consistently.
“The people who are arguing for natural immunity (over) vaccine-elicited immunity often do so with the assumption that natural immunity is superior,” Miller said.
“And in the context of COVID-19, and especially in comparison to our COVID mRNA vaccines, there’s just not strong evidence that that’s the case.”
In fact, there’s some research that suggests that isn’t the case.
One study published on June 30 in Science Translational Medicine found people who were fully vaccinated with the Moderna vaccine had antibodies that were more broadly protective against variants than the ones produced by COVID-19 patients.
The CDC published similar findings. Among Kentucky residents who caught COVID during 2020, the ones that were unvaccinated were more than two times more likely to be re-infected compared to the residents who were fully vaccinated.
On top of that, COVID-19 infection can weaken your immune response, according to a June study published by the University of Oxford, which could put you at higher risk of catching a variant of COVID-19.
Compared with fully vaccinated people, unvaccinated individuals are also seven times more likely to catch COVID-19, 25 times more likely to be hospitalized, and 60 times more likely to be in the ICU due to the disease, according to a new report from the Ontario COVID-19 Science Advisory Table.
However, if you still get your jab after having recovered from COVID, Miller said something interesting can happen: an even higher level of immunity reportedly takes root.
“There’s really excellent evidence now that people who have had a prior infection and are then vaccinated are the best protected of all,” said Miller.
In fact, they may be able to achieve that level of protection with just one jab, studies published in the New York Times suggested. Chakrabarti agreed.
“People who have gotten infected, the evidence actually shows, if you get a single dose of the vaccine after that, that’s actually very robust immunity,” he said.
The risks of pursuing natural immunity
Natural immunity is also a dangerous thing to pursue, doctors warned.
In Alberta, a number of residents ended up in the ICU after reportedly having a COVID party in an intentional bid to contract COVID-19 and gain antibodies against the virus.
“By necessity, to get to immunity, you first have to go through the process of infection,” Miller said.
“And in the context of COVID-19, obviously, those infections can be very severe and sometimes fatal.”
Chakrabarti agreed with Miller.
“To intentionally expose yourself if you haven’t been, that’s not advisable, given that there’s a risk of you getting ill, there’s a risk of other people getting ill,” he said.
Intentionally exposing yourself to COVID-19 at a party, Chakrabarti added, “can result in significant spill over into the community.”
“When you’re in…a region that has a very, very stretched hospital capacity, and now you have one of many types of events where multiple people get sick and potentially hospitalized, it just adds to the strain,” he said.
Some people might not even know that they have an underlying condition, too, which Miller said can put them at serious risk if they catch COVID-19.
“They assume they’re low risk, but then get infected and some underlying condition that they weren’t aware of before then surfaces and they wind up on life support or in the worst case scenario, dead,” he said.
“It’s rolling the dice in a way that’s really irresponsible at an individual level and then even more irresponsible at the community level.”
A nuanced approach
And while Chakrabarti says we should make sure we aren’t “throwing the baby out with the bathwater” when it comes to the potential benefits of natural immunity, it’s also important to keep those benefits in perspective.
“This should not be a topic that is controversial just because there are individuals who are…distorting the message,” he said.
“We should be able to talk about these very important infectious disease issues for what they are: it’s a scientific concept that has implications.”
Miller agreed that there is “truth” to the fact that “natural immunity is immunity and we can be protected by it.”
“But it’s not a wise strategy to achieve immunity by choice.”View link »