October 12, 2021

COVID-19 vaccines offer more reliable, durable immunity than infection-based immunity

A box of COVID-19 vaccine vials

Madison, Wis. – Both COVID-19 infection and vaccination against the virus create immunity, but they are not necessarily equal, according to UW Health experts.

Even with vaccines widely available, many remain hesitant to get the shot, and some cite immunity created by previous infection as the reason they don’t pursue vaccination.

Although infection may generate an immune response, vaccination is the most reliable and durable immunity to COVID-19, according to Dr. Jeff Pothof, chief quality officer and emergency medicine physician, UW Health.

COVID-19 can cause severe illness or death and at the individual level it is hard to predict who will have a mild case, severe illness or long-term health issues after a COVID-19 infection, he said.

“The COVID-19 vaccines were studied through comprehensive clinical trials and produced extensive data,” Pothof said. “That data shows us that they produce reliable, highly effective and more durable immunity.”

Current evidence suggests that in the 90 days after recovering from COVID-19, reinfection is uncommon, but experts still don’t know how long this protection lasts. Plus, about one-third of people who had COVID-19 don’t generate an immune response, so the risk of severe illness and death from COVID-19 far outweighs any benefits of infection-based immunity, according to the Centers for Disease Control and Prevention.

Additionally, infection-based antibody response went down after 60 days for about 94% of healthcare workers who had COVID-19 and recovered, according to a study in the CDC’s Morbidity and Mortality Weekly Report (MMWR).

People with previous COVID-19 infections are more than twice as likely to be re-infected than those who were fully vaccinated after initially contracting and recovering from the virus, according to a separate article in the MMWR.

“COVID-19 vaccination offers better protection than infection-based immunity alone,” Pothof said. “It’s also important for people to know that if you were infected more than 90 days ago, your immunity is decreasing at this point and you may be at risk for re-infection.”