While a recent study said natural immunity to COVID-19 gained through a past infection can provide similar protection to the virus as vaccinations, doctors continue to recommend getting vaccinated and boosted against the virus to reduce the risk of serious outcomes.
The study in the Lancet found, through an examination of approximately 65 other medical studies from 19 countries, immunity to COVID-19 gained through a past infection is similar to that from vaccinations, providing approximately a 10-month period of protection against severe illness or death.
If you’re trying to gain that initial immunity, though, doctors say getting it through vaccinations is preferable to just catching the virus.
“We still want and prefer the vaccination over the infection,” said Dr. Roberto Colon, chief medical officer at Miami Valley Hospital. “You don’t have to have any other risks.”
Natural immunity gained from the original virus and earlier variants appeared stronger than the natural immunity gained from the omicron variant. Immunity from the original early strains of the virus showed around 78% immunity from reinfection around the 40-week mark. This was compared to 36% immunity gained from previous omicron infections at that same time period, the study showed.
The protection from severe illness or death was similar for all strains of the virus, including the omicron variant. The protection against serious outcomes was between 80-90% at 40 weeks.
Gaining immunity naturally through exposure to the virus may not be worth the risk, though.
“People who get COVID are still dying from COVID in some cases,” Colon said. Individuals, including young people, who catch COVID are additionally facing some cardiac complications following the infection.
Cardiac complications, like myocarditis, an inflammation of the heart muscle, have been associated with COVID-19 and the COVID vaccinations. Both the Centers for Disease Control and the American Heart Association say the risk of developing myocarditis is substantially higher through getting the virus than it is in the weeks following a vaccination.
In a study published in the American Heart Association’s medical journal Circulation, researchers analyzed records from England’s National Immunization database for nearly 43 million people 13 or older who had received at least one dose of a COVID-19 vaccine between Dec. 1, 2020 and Dec. 15, 2021. More than 21 million had received three doses of the vaccine – the initial two-shot regimen plus a booster. Nearly 6 million tested positive for COVID-19 either before or after receiving a vaccine. During the one-year study period, 2,861 people – or 0.007% – were hospitalized or died with myocarditis.
The analysis showed people infected with COVID-19 before receiving a vaccine were 11 times more at risk for developing myocarditis within 28 days of testing positive for the virus. But that risk was cut in half if a person was infected after receiving at least one dose of a COVID-19 vaccine. Myocarditis and pericarditis, inflammation of the outer lining of the heart, have rarely been reported following vaccination, according to the CDC.
Informing future policies
Studies on natural immunity gained from COVID infections could go on to inform future policies regarding vaccination recommendations, Colon said. Doctors could use this information to make patient decisions on when they should get vaccinated, possibly deciding to space out when they get the vaccine in order to prolong that duration of immunity if patients already had natural immunity.
“I think we’re going to be figuring out how this data fits into our policy making in the future,” Colon said. He said the goal is always to protect as many people as possible and be the least restrictive as necessary.
“I think this is going to help us be much more targeted,” Colon said.
For some individuals who are at less of a risk of developing a severe outcome or dying from the virus, natural immunity may be sufficient for longer periods of time between vaccination shots. Others who are in higher risk professions, like within the medical field, may need more routine vaccinations.
Determining the best response to the virus, though, means adapting to new information as it becomes available. Colon said this is still a new virus that doctors have only been dealing with for a few years, compared to the decades of experience it sometimes takes for doctors to understand a disease.
“I think what we’re learning from it is how to continue to evolve our thinking,” Colon said.