After getting just one shot of a Covid-19 vaccine, people who were previously infected showed antibody levels equal to or above those of people who had gotten both doses but never been infected, according to a study published Monday.
Those with previous infections also appeared to have more generalized side effects after the first dose, such as fatigue, fever and muscle pain -- similar to what other participants might be expected to have after a second dose of an mRNA vaccine, the researchers wrote.
The authors of this preprint study, which has not been peer reviewed, argued that changing policy to give these individuals only one dose would "spare them from unnecessary pain and free up many urgently needed vaccine doses.”
How the research was conducted: The study involved 109 vaccine recipients, 41 of whom were previously infected with the virus.
The study does not specify which vaccine participants received or how severe their illness was when they were infected with the virus.
People who had not been infected before showed a "relatively low” antibody response in the first nine to 12 days after vaccination, researchers said.
People with previous infections quickly developed high antibody titers "within days," which were measured to be 10 to 20 times higher at times.
The study did not demonstrate whether that resulted in a greater level of protection from getting infected, and follow-up studies are ongoing.
The US Centers for Disease Control and Prevention says that people should get vaccinated even if they had Covid-19, since it’s yet unclear how long antibody protection lasts.