The US government on Friday updated its Covid-19 mitigation guidance, halving the acceptable distance between students who are wearing masks to at least three feet (0.91 m) from at least six feet, potentially easing the path for schools that have struggled to reopen under previous guidelines.
The new recommendation from the US Centers for Disease Control and Prevention (CDC) is a boost to the Biden administration's goal of reopening in-person learning for millions of public school students without sparking coronavirus outbreaks.
"The revised CDC guidance is a great step," said Dr Amesh Adalja, a senior scholar with the Johns Hopkins Center for Health Security. It "reflects the fact that schools ... are not drivers of infections," he added.
Many schools continue to teach students remotely more than a year after the novel coronavirus prompted widespread closures across the United States.
The new guidance was based on data from schools in Utah, Missouri and Florida that suggests transmission of Covid-19 in schools is relatively low when precautions such as mask-wearing are employed, including in cases where students do not maintain six feet of distance.
The guidance applies to students from kindergarten through high school and in areas with low, moderate, and substantial community transmission of Covid-19.
Middle and high school students in communities with high levels of Covid-19 should stay six feet apart unless their schoolday contact can be limited to a single small group of students and staff, CDC said.
"I want to emphasize that these recommendations are specific to students in classrooms with universal mask-wearing," CDC Director Rochelle Walensky said in a news conference.
Students should continue to maintain six feet of distance when interacting with teachers and other school staff and when eating, the agency said.
The CDC has been under pressure to relax its guidance to schools to help get students back into classrooms. Walensky said this week the agency was looking at data in part from a recent study in Massachusetts that suggested tighter spacing had not increased virus transmission.
One of the CDC studies released on Friday looked at 20 elementary schools in Utah during a period of high Covid-19 transmission in the broader community. It showed that in-school transmission rates among masked students were low even though they maintained an average distance between seats of only three feet.
Many schools do not have the space in classrooms to maintain six feet between students.
Billions for Testing
The guidance urged schools to conduct widespread Covid-19 testing of students, saying regular use of such screening offers added protection for schools unable to assure six feet of separation.
School districts should expand screenings for students participating in sports or other extracurricular activities, and consider universal screening prior to athletic events, the guidance added.
The agency continues to recommend quarantines for anyone who has been within six feet of someone infected with Covid-19 for more than 15 minutes within a 24-hour period.
The White House on Wednesday said it would allocate $10 billion to states to support Covid-19 testing for teachers, staff and students to help facilitate resumption of in-person instruction.
The funding, along with recent US regulatory guidance for screening people without Covid-19 symptoms, will boost demand for coronavirus testing, Quidel Corp Chief Executive Douglas Bryant said.
Quidel may need to give school districts priority over other customers, such as employers, as it allocates its supply of Covid-19 tests, Bryant said in an interview.
"We might preferentially support school testing to the extent we can," Bryant said.
The CDC said students are required to wear masks on school buses and any other forms of public transit they use to get to school. The agency issued an order in February requiring travellers to wear masks when using public transit.
The Biden administration has urged states to prioritize vaccination of teachers and childcare workers, with the goal of getting all of them inoculated by the end of March.