Already had COVID-19? Vaccines boost immunity, not 'wipe out' antibodies
Several studies show that COVID-19 vaccines provide additional protection for those who have been previously infected with SARS-CoV-2, the virus that causes COVID-19. The vaccines are safe and effective at protecting people from getting sick, including those who've already recovered from the disease, and do not "wipe out" natural immunity, as social media posts have falsely claimed.
Dr. Amesh Adalja, an infectious disease expert and a senior scholar at the Johns Hopkins Center for Health Security, told FactCheck.org that vaccination does not eliminate, reduce or replace the antibodies developed after a previous infection in any way.
"Vaccination augments natural immunity, making it more robust and more durable," he said in an email.
Yet hundreds of users of TikTok have rehashed an audio clip, first published as a video earlier this year, that deceitfully claims that COVID-19 vaccines eliminate the coronavirus antibodies developed after a previous infection. The TikTok videos, some of them with over 50,000 and 90,000 likes, show different people listening and reacting to the audio, which starts with a news anchor announcing a warning regarding the COVID-19 vaccines. .
The February clip from KMOV-4, a CBS-affiliated television station in St. Louis, Missouri, inaccurately says: "The Red Cross says anyone who has received their COVID-19 vaccine cannot donate convalescent plasma to help other COVID-19 patients in hospitals. That plasma is made up of antibodies from people who have recovered from the virus, but the vaccine wipes out those antibodies."
The American Red Cross told FactCheck.org in an email that "the original information provided to the local station from the regional communicator was unfortunately misinterpreted during the broadcast." The news station later corrected the information on May 27.
The Red Cross made clear then it was still accepting blood and plasma donations from vaccinated people, but that it had discontinued the convalescent plasma donation program by the end of March. Plasma is the clear fluid part of blood, while convalescent plasma is the plasma of people who have recovered from a disease, which contains antibodies to that disease.
The Food and Drug Administration issued an emergency use authorization for the use of convalescent plasma from people who have recovered from COVID-19 to treat hospitalized patients with the disease on Aug. 23, 2020. On Feb. 4, 2021, after additional studies, the FDA revised the EUA to authorize only the use of COVID-19 convalescent plasma with high levels of antibodies for the treatment of hospitalized patients early in the course of the disease and those who cannot produce an adequate antibody response.
Data from clinical trials showed no clinical benefit in the use of convalescent plasma with low levels of antibodies. In its COVID-19 Treatment Guidelines, the National Institutes of Health says several randomized clinical trials "have not demonstrated the efficacy of convalescent plasma for the treatment of hospitalized patients with COVID-19" who do not have impaired immunity, and the NIH recommend against the use of it outside of a clinical trial. Even for those with with impaired immunity, the NIH said there was "insufficient evidence … to recommend either for or against" the use of high-titer convalescent plasma. .
In a document offering guidance for COVID-19 convalescent plasma donations issued by the FDA in November, before the vaccines were authorized, people who had received a vaccine through a clinical trial were not eligible to donate convalescent plasma. That guidance was updated in January, making vaccinated people eligible if they've had a previous infection, received a diagnosis before they were vaccinated, and are within six months of resolution of COVID-19 symptoms. The guidance is "to ensure that COVID-19 convalescent plasma collected from donors contains sufficient antibodies directly related to their immune responses to COVID-19 infection."
The plasma of those who have been vaccinated but who have not been infected with SARS-CoV-2 is not convalescent plasma, because they were never convalescent. An FDA spokesperson told us by email: "The data supporting the emergency use authorization of COVID-19 convalescent plasma to treat patients hospitalized with COVID-19 was obtained from plasma donations from individuals who had COVID-19, not from vaccinated individuals who did not have COVID-19." The spokesperson said that while a vaccinated person "is protected from getting COVID-19 … there is no data on whether their plasma might be effective for the treatment of hospitalized COVID-19 patients."
People with a previous infection and vaccinated people develop antibodies to SARS-CoV-2, but there is a slight difference. A person who has been infected with the virus produces antibodies to multiple parts of the virus, including the nucleocapsid protein and others, while someone who gets an FDA-authorized or -approved vaccine only produces antibodies to the spike protein of the virus. The fact that the FDA included people with prior infections who were later vaccinated as eligible convalescent plasma donors debunks the myth that vaccine-induced antibodies wipe out antibodies developed after a natural infection.
The Red Cross didn't implement the updated FDA guidance, because it stopped collecting convalescent plasma altogether. In an email to FactCheck.org, a Red Cross representative said the program was ended because of a decline in demand from hospitals, sufficient existing supply, and also "[c]omplex system changes" that would be needed to accept convalescent plasma from vaccinated donors.
The Red Cross told us it continued to test whole blood donations for COVID-19 antibodies until June 14, 2021, and was able to use those with high levels of antibodies as convalescent plasma.
In July, the Red Cross tried to debunk the misinformation with a Q&A on COVID-19 vaccines and blood or plasma donation eligibility.
"There are claims circulating that incorrectly state that the Red Cross will not accept convalescent plasma donations from those who have received the COVID-19 vaccine because 'the vaccine wipes out those antibodies making the convalescent plasma ineffective in treating other COVID-19 patients.' This is not accurate," it says (emphasis is the Red Cross').
Dr. Rachel M. Presti, an associate professor of medicine at the Washington University School of Medicine in St. Louis who helped conduct clinical trials for the COVID-19 vaccines and has studied the immune response to SARS-CoV-2 after infection and vaccination, says there is no evidence that the vaccines wipe out natural immunity to SARS-CoV-2, or to any other infection.
"That would be something that would be … very readily abundant in the trials and especially in the initial safety studies. You know, we can detect, on a typical blood test, how much antibody you have in general, and we don't see that change significantly after vaccination," she said in a phone interview. If the vaccine could wipe out people's entire immune system, the billions of vaccinated people would be getting infections all the time, she said, "[a]nd we are not seeing any of that clinically."
Vaccination boosts immunity
What Presti and other researchers have seen is that the vaccines significantly improve the immune response to the virus for those with previous infections. In fact, people with previous infections who get vaccinated develop what researchers are calling "hybrid immunity" or even "super-immunity."
"What we've seen in our studies is people who got infected and then got vaccinated, have higher levels of antibodies to the spike protein, that protective antibody, than people who just got vaccinated," Presti said.
A study that looked at the immune response prompted by the mRNA vaccines in people with and without previous coronavirus infections, published by a team from the University of Pennsylvania Perelman School of Medicine in Science Immunology in April, found that "in SARS-CoV-2 recovered individuals, antibody and memory B cell responses were significantly boosted after the first vaccine dose." A more recent study published by the team in Science in October found similar results.
Even though studies have found that most people who recover from COVID-19 are protected against reinfection, the strength of the immune response among people can vary and the duration of it remains unclear.
"Some people actually have fairly low antibody responses that are not sufficient to neutralize the virus, especially variant viruses. When you vaccinate them uniformly, you get high antibody titers [measurements] and high neutralization titers, so there's an improvement in at least one of the key metrics of immunity following vaccination," E. John Wherry, director of the University of Pennsylvania's Institute for Immunology and one of the lead authors of the studies, told FactCheck.org in a phone interview in April.
The Centers for Disease Control and Prevention recommends people who have recovered from COVID-19 get a vaccine because "research has not yet shown how long you are protected from getting COVID-19 again" after recovering, and because "vaccination helps protect you even if you've already had COVID-19."
A CDC study released in August found unvaccinated Kentucky residents who were previously infected with SARS-CoV-2 but remained unvaccinated were "more than twice as likely to be reinfected" with the virus than those who got a vaccine after an infection.
Not all nurses and doctors have natural immunity to COVID-19
In the midst of states and countries requiring health care workers to get vaccinated, one Instagram post pushing this claim also falsely stated that nurses and doctors don't need vaccines "by definition" because everyone "who has worked in a hospital in the last two years without a v now has natural immunity..
That's not correct. Johns Hopkins' Adalja told us that although some nurses and doctors "have a degree of natural immunity if they were infected with the virus," studies show that not all of them have antibodies.
"For example, I have been taking care of COVID patients throughout the pandemic and had antibodies checked twice before I received my vaccine and was negative," he wrote.
One study conducted by the CDC collected serum samples from frontline health care workers who worked with COVID-19 patients at 13 medical centers in the U.S. from April 3 to June 19, 2020. It found that 6% of 3,248 participants had positive test results for SARS-CoV-2 antibodies. That's because the only way to get antibodies against the coronavirus at the time — before the vaccines were authorized — was to get infected by the virus, and not all health care workers got infected.
"Working on the frontlines doesn't necessarily give you immunity," Presti told us. "The reason that not all doctors and nurses got sick and died from COVID isn't because they had natural immunity, it's because they were wearing protective gear — so masks, and gowns, and gloves, and face masks, so on..
The World Health Organization estimated that as of May 24, at least 115,000 health care workers have died from COVID-19 globally. And according to an International Council of Nurses report published in March "millions of COVID-19 infections have been reported among healthcare workers globally," and about 3,000 nurses in 60 countries have died because of COVID-19.
"Nurses, their colleagues, and their peers, remain vulnerable to COVID-19, especially when unvaccinated," the American Nurses Association, which supports the vaccine mandates, told FactCheck.org in an email. "Even with natural immunity, vaccination enhances immune response and provides additional protection in the absence of clear data that indicates the duration and strength of natural immunity in the presence of highly transmissible variants, such as Delta."