Applicability of findings to today questioned
Dr. Blumberg also questioned whether the study, which was completed almost a year ago, reflects the current pandemic landscape.
“At the time this study was done, it was predominantly Delta [variant instead of Omicron],” Dr. Blumberg said. “The other issue [with the study] is that … most of the children didn’t have preexisting immunity, so you have to take that into account.”
Preexisting immunity – whether from exposure or vaccination – could lower viral loads, so asymptomatic children today really could be less contagious than they were when the study was done, according to Dr. Blumberg. Kids without symptoms are also less likely to spread the virus, because they aren’t coughing or sneezing, he added.
Sara R. Kim, MD, and Janet A. Englund, MD, of the Seattle Children’s Research Institute, University of Washington, said it’s challenging to know how applicable the findings are, although they sided more with the investigators than Dr. Blumberg.
“Given the higher rate of transmissibility and infectivity of the Omicron variant, it is difficult to make direct associations between findings reported during this study period and those present in the current era during which the Omicron variant is circulating,” they wrote in an accompanying editorial. “However, the higher rates of asymptomatic infection observed among children in this study are likely to be consistent with those observed for current and future viral variants.”
Although the experts offered different interpretations of the findings, they shared similar perspectives on vaccination.
“The most important thing that parents can do is get their kids vaccinated, be vaccinated themselves, and have everybody in the household vaccinated and up to date for all doses that are indicated,” Dr. Blumberg said.
Dr. Karron noted that vaccination will be increasingly important in the coming months.
“Summer is ending; school is starting,” she said. “We’re going to be in large groups indoors again very soon. To keep young children safe, I think it’s really important for them to get vaccinated.”
The study was funded by the CDC. The investigators disclosed no other relationships. Dr. Englund disclosed relationships with AstraZeneca, GlaxoSmithKline, Merck, and others. Dr. Kim and Dr. Blumberg disclosed no relevant conflicts of interest.