Many of us thought the end of the pandemic was within sight when the first COVID-19 vaccinations started rolling out last year. However, it is clear that COVID will be with us for the long term.
We need many tools to manage this virus — vaccination, proper masking, ventilation in indoor spaces, and testing are the primary ones, with widespread vaccination the most crucial. But waning immunity and evolving variants remind us that our work to limit the pandemic has not been a one-way march but, instead, a series of steps forward and back.
Effective management requires prevention of new cases, hospitalizations, and deaths, but also restoring stability to everyday life. Unpredictability and patchwork policies for K-12 schools, for example, have wreaked havoc for families and employers.
Against this backdrop, testing technologies and strategies are paramount. Rapid antigen tests, which can be purchased by consumers and used at home with quick results, are a critical tool, given their ability to identify when people have high viral loads and are most infectious.
However, the United States does not have a nationwide plan for use of rapid tests. Some public health experts have suggested making rapid tests universally available through mail, retail stores, or other distribution points. But capacity in early 2022 will be around 300 million rapid tests per month. Making weekly tests available to even 75 percent of Americans requires 1 billion tests per month. Many of us who have looked for rapid tests at drug stores in recent weeks were met with empty shelves. The wait for walk-up testing can be an hour or more.
The federal government can facilitate manufacturing and procurement and can set rules on activities such as airline travel. Beyond that, policy and allocation decisions probably will be made at state and local levels and by employers. Illinois recently announced that rapid tests at state and local health department testing sites would be available only to individuals under 18 or symptomatic individuals over 50. In December, Governor Charlie Baker announced the distribution of 2.1 million at-home tests to hard-hit communities. It’s a laudable but temporary measure; once the allotment of tests has been used, more will be needed.
We recommend organizing testing strategies in terms of three kinds of testing: surveillance, screening, and self-testing. Surveillance includes regular testing of key populations — such as school-age children — to monitor for outbreaks. Screening requires a negative test to participate in an activity — such as those traveling internationally or attending an event, or for school children exposed to the virus. This helps prevent transmission by identifying individuals who are infected. Used properly, it can also identify those who can safely join in-person activities because repeated negative test results imply very low transmission risk.
Self-testing, which has gained increased attention with the arrival of Omicron, covers at-home testing done at the discretion of an individual. It might be used before gathering with friends, or in the event of COVID-like symptoms.
Among the three categories, surveillance requires the most planning to realize its full benefit and should use current evidence. Many universities deployed surveillance testing this fall to guide policy. At Brown University, for example, a mild increase in cases led to targeted interventions such as suspension of in-person dining by students. When cases subsided, the restrictions were lifted, and when case counts reached single digits per week, surveillance testing was scaled back to include only those with vaccination exemptions. Asymptomatic testing continues to remain available for faculty and staff.
A critical benefit of surveillance is information: Evidence of low case rates gives members of the community confidence to engage in person. When rates go up, targeted measures can be used in place of blunt interventions such as closing schools or locking down campuses. Early detection also enables early treatment when needed. PCR testing typically is used for surveillance because results can be reported directly to local health agencies by the lab that generates the test result. A reporting system for rapid test results, such as the one currently used by Washington D..C, could enable rapid testing to be used for surveillance.
Up to now, many K-12 school testing programs have been ad hoc or nonexistent. Local governments need the resources to implement evidence-based screening strategies. The CDC now recommends test-to-stay, a screening program that allows a series of negative tests to take the place of days spent quarantining after a possible exposure. This keeps more kids in school, does not single out children who are unvaccinated, and minimizes time spent at home for children who become ill.
We are entering yet a new uncertain phase of the pandemic. In addition to the incomprehensible loss of life, we are collectively exhausted by the anxiety and uncertainty associated with carrying out basic functions of our lives.
Used in conjunction with lab-based PCR testing, rapid antigen testing is a fundamental tool needed to limit this pandemic, but for now it is a limited resource. Devising a long-term, adaptable strategy for surveillance, screening, and self-testing can meet the continuing challenges of an unpredictable pandemic.
Joseph Hogan is professor and chair in the department of biostatistics at Brown University School of Public Health. Alyssa Bilinski is assistant professor of health services policy and practice, and of biostatistics, at Brown University School of Public Health. Elizabeth Stuart is professor of mental health, biostatistics, and health policy and management and vice dean for education at Johns Hopkins Bloomberg School of Public Health. Joshua Salomon is professor of health policy at Stanford University School of Medicine.