Fact Check-Study did not conclude that people who have been infected with COVID-19 are protected for life

A study published by researchers at Washington University School of Medicine in St. Louis did not conclude that people who have had COVID-19 are protected for life, despite claims made online.

The study cited as proof on social media that infection leads to life-long protection from COVID-19 was released in May 2021 in the journal Nature is viewable (here).

The study analyzed blood samples from 77 participants and bone marrow from 18 of the participants to assess whether they had any immune memory in the months post-infection.

One user said on Twitter: “BREAKING REPORT: Washington University School of Medicine RELEASES DATA claiming If You’ve Had COVID You’re Likely PROTECTED FOR LIFE...” (here).

A blog post citing the study was published on Dec. 21, 2021, with a headline that reads: “If You’ve Had COVID You’re Likely Protected for Life”. (here).

Users referred to a press release published by the university which did indeed say that the study found that people who had a mild illness developed “antibody-producing cells that can last a lifetime.”

The study had 77 participants who had recovered from a SARS-CoV-2 infection and 11 individuals who had never been infected as control. The participants provided blood samples that were analyzed at three-month intervals beginning one month after infection.

The study found that antibodies in the blood dropped quickly in the first few months and subsequently plateau - not a complete drop-off - with antibodies detectable in the blood at the 11-month mark.

Eighteen of the participants provided bone marrow samples seven to eight-months post-infection, and five of the 18 returned four months later to provide a second bone marrow sample (here). Another individual who recovered from the disease provided a bone marrow sample separately.

Bone marrow plasma cells (BMPC) were detected in 15 of the 19 samples and BMPC was detected in four of the five samples that were provided four months later, at the 11-month mark (here).

In the press release released by the university, senior author of the study and Associate Professor of Pathology and Immunology at Washington University School of Medicine, Ali Ellebedy, said that these cells are “quiescent, just sitting in the bone marrow and secreting antibodies. They have been doing that ever since the infection resolved, and they will continue doing that indefinitely” (here).

Ellebedy told Reuters that the study did not show nor claim that people infected from mild SARS-CoV-2 infection are protected for a lifetime.

“Having detectable antibody response in blood for life does NOT equal being ‘protected’ for life. Not all antibodies are protective especially if the virus they are raised against is constantly changing,” Ellebedy told Reuters.

“Our study showed that people who recover from a mild SARS-CoV-2 infection develop an immune memory in the form of memory B cells and plasma cells. The latter are just antibody producing cells that take up residence in our bone marrow and survive for protracted period of time. This response would be similar to our response to any other mild virus infection and [that’s] what we wanted to show,” Ellebedy said (here), (here).

The abstract of the study found that a “mild infection with SARS-CoV-2 induces robust antigen-specific, long-lived humoral immune memory in humans” (here).

This means that the “immune system of those who recovered from the infection has now dedicated special cells to remember that virus and those cells will be ready to quickly reengage in case of re-exposure,” Ellebedy explained to Reuters.

“Immunity in our line of work means ‘detectable antibodies’ which is evidence of a successfully mounted immune response. No relation to ‘protection,’ which is a completely different term that depends on having some immunity but also many other factors, like age, medications, health status, other chronic conditions … etc. It also depends on what [sic] the exact virus that caused the reinfection. If the virus is too different from the original virus, then the benefit from the previously developed immunity becomes more limited,” he added.

Ellebedy tweeted on Dec. 22 in response to the blog, calling it “full of misinformation” (here).

The Centers for Disease Prevention and Control (CDC) recommends that individuals who have previously been infected also get vaccinated to better protect against the disease (here), (here).

Strength and length of immunity following infection is still being studied. Some studies suggest that infection may provide strong immunity (here), (here), (here).

Meanwhile, a study released by the CDC in Nov. 2021 analyzed data from hospitalized adults and found that the odds of laboratory-confirmed COVID-19 among unvaccinated individuals who had a prior infection were 5.49-fold higher than the odds among fully vaccinated people who received an mRNA COVID-19 vaccine and had no prior infection (here).

Other studies into immunity post-infection and/or vaccination can be seen (here), (here), (here), (here).


False. A study released in May 2021 by researchers at Washington University School of Medicine in St. Louis, has been shared widely online in December 2021 as proof that people who have previously been infected SARS-CoV-2 are protected for life. The study did not conclude this. Instead, it determined that individuals who provided samples and had previously been infected with the virus developed immune memory in the form of memory B and plasma cells. This is not proof of life-long protection against the virus.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here .