Federal health officials have made it clear that people who are fully vaccinated against COVID-19 can safely dabble in the activities they enjoyed before the onset of the pandemic.
But what about those who are not vaccinated and have recovered from the disease? Do they have the liberty of safely following public health guidance directed at fully vaccinated people? Even further, can people who’ve been infected safely gather with their vaccinated friends and family?
The answers go beyond simple yeses or nos.
“It appears the vaccine induced immunity is more robust than that generated from natural infection — and I wouldn’t consider them equivalent — but natural immunity is certainly not insignificant,” Dr. Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security, told McClatchy News in an email.
Studies have shown protective antibodies gained from natural infection can last at least three months or up to eight months — other evidence suggests it could last for years. This is why the risk of reinfection is considered low in the months after a first round with the virus, the Centers for Disease Control and Prevention says, “but may increase with time due to waning immunity.”
Vaccines, on the other hand, offer predictable and measurable protection, experts say — and in some cases, protection that is safer than that from natural infection.
A letter to the editor posted in the New England Journal of Medicine said that people who received the Moderna COVID-19 vaccine had more antibodies in their blood than non-vaccinated people who had recovered from the disease.
A study released in March provides “strong evidence” that the Pfizer and Moderna vaccines are capable of preventing infections — both those that cause symptoms and those that don’t — in real-world conditions. That is, outside the controlled laboratory settings where the initial clinical trials took place.
It found that risk of coronavirus infection dropped by 90 percent two weeks after receiving a second, final dose and by 80 percent two weeks following a single dose among nearly 4,000 health care workers, first responders and other essential workers across six states.
However, the duration of immunity from either vaccination or natural infection is unclear. That’s why the CDC recommends people get vaccinated regardless of past infection.
Coronavirus variants add another enigma, Adalja said.
All five of the “variants of concern” spreading in the U.S. are capable of reducing antibody activity in vaccinated people and those who are not vaccinated but have recovered from COVID-19. Variants that were first discovered in the U.K. and South Africa are also 50 percent more contagious than the original coronavirus strain.
Variants that emerged from South Africa and Brazil “appear to be able to more easily get around natural immunity than vaccine-induced immunity,” as well, Adalja added.
Therefore, “a recovered person is an intermediate category between a totally naive person and one that is fully vaccinated,” he said.
The CDC, which recently announced updated guidance for fully vaccinated Americans, agrees.
“The two groups are not the same,” a CDC spokesperson told McClatchy News in an email. “The [new] guidance is for fully vaccinated people. A person is considered fully vaccinated two weeks after receiving the last recommended dose of vaccine.”
In other words, unvaccinated people who have recovered from the disease should assume they don’t have protection against the coronavirus when deciding what activities are safe, at least until they get vaccinated.
The updated recommendations released last week say people who are two weeks post their final doses of the Pfizer, Moderna or Johnson & Johnson vaccine can ditch masks when outdoors “except in certain crowded settings and venues,” such as live performances, parades or sports events. Vaccinated Americans should still wear masks indoors, however, especially when around unvaccinated people.
People who are not vaccinated should continue precautions such as mask wearing, physical distancing and hand washing under all indoor and outdoor circumstances where infection risks are high.
The most relevant CDC guidance for people who have recovered from COVID-19 involves testing and quarantine.If a person who had COVID-19 is exposed to someone who tested positive within three months since getting infected, they do not need to get tested or quarantine. If exposure happens three months or more since initial infection, then people should follow quarantine recommendations and get tested.