"Antibodies elicited by infection do not neutralize the currently circulating coronavirus variants as efficiently as antibodies elicited by mRNA vaccination," Scott Hensley, an associate professor of microbiology at the University of Pennsylvania, previously told USA TODAY. A June 30 study published in Science Translational Medicine found antibodies produced by those fully vaccinated with Moderna's mRNA vaccine were more broadly protective against different variants, compared to antibodies of recovered COVID-19 patients.
Vaccines also provide much more consistent protection from infection than natural immunity, said Grant McFadden, director of the Biodesign Center for Immunotherapy, Vaccines and Virotherapy at Arizona State University."Recovery from COVID results in very variable immunity to a second infection, and this is reflected in the wide range of anti-spike antibodies in recovered patients," McFadden told USA TODAY. "On the other hand, the immunity from the vaccines (especially the messenger RNA versions) is much more uniform, both in terms of protection from COVID and in anti-spike antibody levels."
A University of Oxford study published in June found that people with weaker immune responses from a previous COVID-19 infection could be at a higher risk of contracting new viral variants. Vaccines also induce the body to produce antibodies at levels even higher than those who have recovered from COVID-19, Dr. Taylor Heald-Sargent, assistant professor of pediatrics specializing in infectious diseases at Northwestern University Feinberg School of Medicine, told Health. "The vaccine elicits many more antibodies than a natural infection, so as the vaccine declines, the protection lasts longer than it would from a natural infection," she said.
Antibodies are made by the arm of the immune system called the adaptive immune response, which keeps a memory of any pathogen the body has ever encountered and launches a more specialized attack if they invade again. Research has suggested COVID-19 infection can lead to a reservoir of protective antibodies lasting up to eight to 11 months. But these antibodies don't necessarily prevent reinfection, as one recent CDC study and others have discovered.