Two new studies indicate COVID-19 vaccine immunity lasts at least a year

Two new studies indicate that the COVID-19 vaccine could give recipients immunity to the virus for at least a year, and potentially longer, raising more questions about whether certain individuals will require booster shots. 

The New York Times reported on Wednesday that the studies imply that many people who contracted COVID-19 about a year ago, recovered and now have been vaccinated will likely not need the extra shots. 

But the studies and experts suggest that people who never caught the virus will most likely require a booster, as will other previously infected individuals who do not have a strong immune response. 

One of the studies found that B cells that hold a memory of the virus linger in a person’s bone marrow and can produce antibodies to fight COVID-19 when necessary.

Washington University School of Medicine in St. Louis associate professor Ali Ellebedy led a team for that research, published in the journal Nature on Monday.

The researchers studied the blood of 77 people every three months beginning about a month after getting infected with COVID-19. The antibody levels in these patients plummeted four months after initial infection and then started a steadier decline. 

“It tells me that even if you got infected, it doesn’t mean that you have a super immune response,” Ellebedy told the Times.

The team also collected bone marrow samples from 19 people about seven months after contracting the virus, finding 15 with the applicable B cells and four without.

The other research indicated that the B cells can grow and become more powerful for at least a year after the person first contracted COVID-19. That study, however, was posted to a website that publishes research before it’s peer-reviewed, according to the Times.  

Michel Nussenzweig, an immunologist at Rockefeller University in New York, led this B cell study, which also found that these cells can be powerful enough to combat variants after initial infection and then vaccination. The ability to fight variants would invalidate reasoning that boosters are needed to resist COVID-19 variants. 

“People who were infected and get vaccinated really have a terrific response, a terrific set of antibodies, because they continue to evolve their antibodies,” Nussenzweig told the Times. “I expect that they will last for a long time.”

In Nussenzweigh’s study, the researchers examined blood from 63 people who had coronavirus a year prior, with most having mild symptoms. Twenty-six of these people had gotten at least one dose of the Moderna or Pfizer-BioNTech vaccines. 

The immune systems of people without the vaccine demonstrated a lower immune response against all forms of the virus, especially the variant first found in South Africa, indicating that COVID-19 infection alone did not lead to immunity. 

These results contradict an argument that those who contracted COVID-19 do not need the vaccine because they’re immune.

Sen. Rand Paul (Ky.) is among the Republicans who have said they don’t plan on getting the vaccine after previously being infected with the virus last year. 

The studies come amid discussions over whether booster shots will be necessary to protect the public from COVID-19 as variants spread, and as the U.S. is still fighting to reach the so-called herd immunity point. 

President Biden’s chief medical adviser Anthony Fauci said Wednesday that it’s unclear when a booster shot will be needed for the vaccine — but that it probably will be at some point. 

“I don’t anticipate that the durability of the vaccine protection is going to be infinite — it’s just not,” Fauci said during a Senate Appropriations subcommittee hearing. “So I imagine we will need, at some time, a booster.”

Executives at Pfizer and Moderna, whose companies have made billions from their vaccines, said last week that the first booster shots could be necessary for Americans who got their shots early this year as soon as the fall.