Weekly testing of students and educators is a key part of President Joe Biden’s plan to reopen a majority of K-8 schools in the country to in-person learning within 100 days, and all K-12 schools soon thereafter.
The Rockefeller Foundation has been working closely with the Biden administration and, consequently, Biden’s rapid Covid testing plan for schools is similar to TAKING BACK CONTROL: A Resetting of America’s Response to Covid-19 that the foundation released in December. The plan advocates for testing students once per week for Covid-19, and teachers and staff twice per week.
The Rockefeller Foundation plan estimates the nation’s K-12 schools will require 300 million Covid-19 tests each month from February through June at a cost of $8.5 billion per month. Biden has called for a $50 billion investment in a massive expansion of the nation’s testing capabilities, including at schools.
Beyond funding, successfully implementing testing on such a scale will require mass production of fast, inexpensive, and accurate tests, says Mara G. Aspinall, a co-author of the Rockefeller Foundation report and professor of practice at Arizona State University’s College of Health Solutions.
“It's likely that we will use a mix of [testing] technologies, including PCR-pooled, PCR, and antigen tests,” Aspinall says. Regardless of the type of test, “It is essential that results are available to schools very, very quickly.”
PCR Tests
Polymerase chain reaction, or PCR tests, detect genetic material – the RNA – of the virus, and are highly sensitive and accurate. But these tests generally need to be analysed in a lab, which makes getting results expensive and often slow. Pooling PCR tests, mixing samples from many people together and then testing the sample as one, is a way of making PCR tests more efficient. If a pooled test comes back positive, each member of that pool can then be tested individually.
The Rockefeller Foundation calls for improving PCR lab capacity by building or expanding 6 to 10 high-capacity regional labs throughout the country that will be able to ensure a 24-hour turnaround on all tests.
Dr. Gigi Kwik Gronvall of the Johns Hopkins Bloomberg School of Public Health says that pooled testing is a cost-effective strategy for schools when spread of the virus is low, but grows more expensive as cases rise. “If you're going to have to keep doing rounds of tests, because you have a positive case that's going to be a problem,” Gronvall says.
Antigen Tests
An alternative to pooled PCR tests are antigen tests, which detect a protein that is part of the coronavirus. These are less expensive to make and provide results faster than PCR tests. Though less sensitive than PCR tests, antigen tests are nearly as good at identifying those most likely to transmit infections to others, according to the Rockefeller Foundation plan.
“The tests are presumably much more effective at detecting people who are spreading virus, as opposed to people that are carrying virus,” says Dr. Howard Forman, of The Yale School of Public Health. The fact that antigen tests are almost instantaneous is another advantage. “After you have symptomatic disease, it's easy to pull people out of the population,” says Forman. “It's that 24- or 48-hour window before you have symptoms that you’re most dangerous.”
In October, the U.S. Department of Health and Human Services partnered with the Rockefeller Foundation to launch a program to send more than 120,000 Abbott BinaxNOW antigen tests to six pilot areas: Washington D.C.; Louisville, Ky.; Los Angeles; New Orleans; Tulsa, Okla.; and Rhode Island. The program was designed to gauge the tests’ effectiveness in keeping schools open and its results are currently being studied.
Will This Testing Strategy Work?
Experts are optimistic that if implemented, this plan can help schools fully reopen to in-person classes and that more rapid testing in the general population can help the nation’s overall pandemic response.
“I'm in this cohort of people who believe that testing from the first moment of the pandemic has had far more potential to do good than we've ever allowed it to do,” Forman says. “We spend an awful lot of time testing where the results come back late, or testing where it's symptomatic people where we already know they should be isolating. We should be doing so much more testing on asymptomatic individuals. There's almost no limit to how much you can scale this up and have a positive impact. And as the infectiousness of the virus picks up, which we think it is, this can be used to bring the reproduction number down.”
But testing alone won’t be enough. Other mitigation strategies need to be included, such as using masks, social distancing, vaccinating teachers, and improving school ventilation. “The Rockefeller Foundation has been very clear in calling for teachers to be considered essential workers,” Aspinall says. “They should be getting the vaccine as soon as possible.”
Even in a post-pandemic world, some of the covid-mitigation strategies can be useful, Gronall says. Children learn better in well-ventilated schools and testing infrastructure built now could one day be used to test for seasonal flu and other infectious diseases that tend to spread through schools.
“It would be great to see some carrying on of some public health lessons into the future,” Gronvall says. “There's plenty of diseases that would be really nice not to have.”
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