Vaccination status doesn’t impact infectivity timeline in kids

TOPLINE:

Half of kids with COVID-19 become noninfectious 3 days after testing positive, whether they were vaccinated or not, according to a new study. The findings indicate that return-to-school policies for infected children may not need to differ on the basis of vaccine or booster status.

METHODOLOGY:

• The study looked at 76 children, both vaccinated and unvaccinated, aged 7-18 years who had tested positive for COVID-19.
• Researchers performed nasal swabs every other day for 10 days, sending the swab to a lab to be tested for cytopathic effect (CPE), or cell death, an indicator of infectivity.
• They took pictures of the lab cultures to look for signs of CPE starting at 6 days after the test, which corresponds to the 2nd day after testing positive.
• If CPE characteristics were present in at least 30% of images, children were considered infectious.

TAKEAWAY:

• By day 3, half of study participants were noninfectious, independent of whether they had been vaccinated.
• By day 5, less than 25% of children were infectious, regardless of vaccination status.
• Among vaccinated children, the duration of infectivity was similar for children who received a booster and for those who had not.
• The authors state that these results are consistent with those of a study in adults with the Omicron variant, which found no association between vaccination status and infectivity duration.

IN PRACTICE:

“Our findings suggest that current policies requiring isolation for 5 days after a positive test might be appropriate, as the majority of children were not infectious by day 5. Additionally, return-to-school policies may not need to discriminate by vaccine or booster status,” the authors wrote.

SOURCE:

The study was led by Neeraj Sood, PhD, of the University of Southern California in Los Angeles, and was published in JAMA Pediatrics.

LIMITATIONS:

The sample size was small, and the authors identified the potential for nonresponse bias. The research did not include data from children who didn’t receive a test. CPE is the standard for estimating infectivity, but it can still carry inaccuracies.

DISCLOSURES:

The authors report no disclosures. The study was funded by RF Catalytic Capital.

A version of this article first appeared on Medscape.com.