New York, Oct 24 : Children infected with the Omicron variant remained infectious for a median time of three days after testing positive for the virus, Indian-origin scientists have found. School policies that require students with Covid-19 to stay out of the classroom for five days are more than sufficient. 'We're basically saying five days is more than sufficient; public-health and education leaders may consider shorter durations,' said study co-author Neeraj Sood, Director of the Covid-19 Initiative and a senior fellow at the University of Southern California's Schaeffer Center. The study found the median time of infectivity was three days, with 18.4 per cent of children still infectious on day five and 3.9 per cent infectious on day 10. It also found no association between how long children were infectious and whether they were vaccinated, suggesting return-to-school policies may not need to discriminate by vaccine or booster status. The study, published in JAMA Pediatrics, seeks to inform policymakers who grapple with how long children must isolate when they contract Covid-19. 'We want to protect the other children in the school who could potentially get infected, but at the same time, we don't want to disrupt education for the child who is infected, given the amount of disruption that's already happened,' said Sood, who is also a professor at the USC Sol Price School of Public Policy. 'The duration of infectivity is an important parameter into figuring out what the optimal duration of self-isolation should be.' For the study, researchers partnered with a virus testing company and examined nasal swabs from 76 children in Los Angeles County who were between the ages of 7 and 18 and tested positive for Covid-19. 'We wanted to capture how infectivity changed over the 10-day window,' said lead author Nikhilesh Kumar from USC Keck School of Medicine. The findings are consistent with previous research on adults who contracted the Omicron variant, which showed no association between vaccination status and time of infectivity. Sood called for further research so policymakers can consider adjusting the time students must stay out of the classroom. 'The virus will keep mutating,' Sood noted. 'We need to continue doing studies like this because the next variant may have a longer or shorter duration of infectivity.' /IANS