- It's unclear how soon the clinical trials needed to vaccinate children against Covid-19 will be completed.
- Until now, most drugmakers working on a potential vaccine have tested only healthy adults.
- Pregnant women and children are often the last to get tested.
As schools consider whether it's safe to reopen this fall, medical experts warn it could take years before students and teachers can return to in-person education safely without masks, social distancing and other measures intended to curb the spread of the coronavirus.
Whether and how to reopen schools in the U.S. this fall has become a hotbed issue in recent weeks, with President Donald Trump and Republicans pushing for in-school learning as soon as possible, even as the coronavirus continues to rapidly spread across the nation. The U.S. has the worst outbreak in the world with more than 5.4 million cases and at least 171,800 deaths as of Wednesday, according to data compiled by Johns Hopkins University.
On Monday, the University of North Carolina at Chapel Hill announced it was canceling in-person undergraduate classes and shifting them to remote learning after a coronavirus outbreak quickly spread across campus, demonstrating how difficult it may be to return to in-person learning anytime soon. The University of Notre Dame is also shifting to online classes after reporting a rise in infections.
Experts say it may take a couple of years before students can resume classes without the risk of an outbreak, especially among grade-school children. They say a combination of herd immunity, a coronavirus vaccine and hygienic practices are needed to bring the virus down to low enough levels and allow schools to safely return to normal.
"You're really going to need all three moving forward," said Dr. Paul Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia. Offit, who was a member of the Advisory Committee on Immunization Practices to the Centers for Disease Control and Prevention, added that social distancing measures are difficult in some school settings.
Public health officials say herd immunity is not likely soon, adding at least 60% to 80% of the population need to have the antibodies to fight off new infections, leaving the virus without enough new hosts to infect.
Scientists expect to find a safe and effective vaccine for the coronavirus by the end of the year or early 2021. However, medical experts say the vaccine is unlikely to be a "magical cure." Health officials are aiming for a vaccine that is at least 75% effective, meaning some individuals may still be at risk of contracting Covid-19, medical experts said.
"If you have a vaccine, you're still going to have to wear a mask and still have to try to social distance," Offit said, adding the vaccine will likely be less effective than the measles vaccination, which is about 93% effective, according to the CDC.
Yanzhong Huang, director of the Center for Global Health Studies at Seton Hall University, agreed, saying the world is in "uncharted territory."
It will be difficult to return to school "in the absence of protective measures like masks, social distancing and washing hands," he said. "I don't think the vaccine itself will be a magic bullet."
Even if the vaccine works better than anticipated, children may not be among the first to be vaccinated, still potentially delaying a return to in-person classes for some, said Daniel Salmon, director of the Institute for Vaccine Safety at Johns Hopkins Bloomberg School of Public Health.
He said it's unclear how soon the clinical trials needed to vaccinate children will be completed. Until now, most of the drugmakers working on a potential coronavirus vaccine have only tested healthy adults. Pregnant women and children are often the last to get tested. AstraZeneca said earlier this year it would test its coronavirus vaccine on children in a phase two trial.
Additionally, the first batches of the potential vaccines will likely go to the most vulnerable people, such as the elderly or health-care workers, he said. "I don't see how we're going to offer mass vaccinations for children" anytime soon.
Infectious disease specialist Dr. Isaac Bogoch said he doesn't believe it will take years for schools to return to normal, considering the millions in investments the U.S. has made on potential vaccines. But he noted in-person education may not return to normal until late into the first half of next year after vaccines are expected to become widely available.
"But then schools may want to see proof of vaccinations," said Bogoch, a professor at the University of Toronto, adding some people will want to opt out.
Dr. Harry Greenberg, a professor of microbiology and immunology at Stanford University School of Medicine, echoed those remarks, saying if "we're lucky" on vaccines, students could return to schools without masks by the fall of 2021.
In the meantime, medical experts say officials should take a region-by-region approach to reopening schools based on the rate of coronavirus spread.
Earlier this month, New York Gov. Andrew Cuomo announced that all school districts across the state have been authorized to reopen for the fall semester, including New York City, the nation's largest school district. New York state, once the epicenter of the outbreak in the U.S., now has one of the lowest infection rates in the country and can feasibly reopen schools, experts said.
New York Mayor Bill de Blasio said Monday the city's Department of Health and Mental Hygiene is preparing to inspect child-care facilities and schools before they reopen in September.
It wasn't surprising that UNC-Chapel Hill had an outbreak, Bogoch said, adding that cases were still high in the state and the school was "not set up for success."
"You've got lots of schools in indoor settings in close proximity to one another for a prolong period of time," he said. "That is a recipe for disaster. That is just a perfect set up for this infection to be transmitted."