Starting in October 2020, researchers in Texas recruited 218 subjects between the ages of 5 and 19 who had recovered from COVID infections at some point in the past.
Each provided three blood samples, at three-month intervals. More than 90% were unvaccinated when they enrolled in the study.
The first blood test showed infection-related antibodies in only one-third of the children, the researchers reported online Friday in Pediatrics .
Six...