We Need a Cheap Way to Diagnose Coronavirus
Covid-19, the new coronavirus, is on the verge of spreading across the world. Large clusters of cases are emerging outside China in South Korea, Italy, and Iran, and the Centers for Disease Control and Prevention (CDC) expects severe disruptions to occur within the United States. More than any recent pandemic, the coronavirus poses new global challenges. As part of its recently announced $2.5 billion push for vaccines, treatments, and protective equipment, the U.S. government must also make the “crash” development of an inexpensive, point-of-care, diagnostic kit for use in clinics and homes a high priority so communities can quickly detect and contain the disease.
For reasons we discussed earlier, vaccines can’t be developed quickly enough: They will not be available to the public for at least a year, said Francis Collins, the director of the National Institutes of Health. Complicating matters, manufacturers capable of producing the coronavirus vaccine in large quantities have yet to commit themselves to producing one being developed by the NIH, according to Tony Fauci, director of the National Institute of Allergy and Infectious Diseases.
In the meantime, the best measure is to test symptomatic patients to prevent or slow the spread of the virus. Testing can also pinpoint “hot spots” where community-wide measures like social distancing (having people avoid others, for instance, by working at home) and home isolation (requiring people with the Covid-19 to stay at home) can be considered. China is already implementing this strategy.
Testing at a broader, global scale may be necessary, however, and would require a point-of-care “rapid” diagnostic kit. We made the same case for combating the less-widespread albeit tragic Ebola and Zika crises. Such broad testing cannot depend on specialized equipment and a relative handful of centralized labs; people need to be tested in clinics and perhaps even at their doorsteps. Our most recent models indicate that in order to control coronavirus within a year, 80% of symptomatic patients would need to be tested and isolated within a day of symptoms appearing. This is consistent with our earlier published modeling for Ebola.
Currently, most pandemic-prone diseases, including coronavirus, are diagnosed by polymerase chain reaction (PCR), a molecular technique that often requires special laboratory machines and highly trained technicians to operate them. PCR tests are difficult to scale or decentralize. Bill Gates points out that portable versions of these molecular diagnostic machines need to be distributed throughout Africa to prevent the spread of coronavirus.
However running the test machines also requires a consumable test kit, and the number of coronavirus cases in China has exceeded its laboratory testing capacity due to a shortage of PCR testing kits. Consequently, China has had to resort to using CT scans as a hospital-based rapid test to screen infected patients for coronavirus, followed up by laboratory-based testing for confirmation. Many clinics do not have the expensive machines to do CT scans. If the number of people who need to be tested in the United States exceeds a small percentage of the population, the U.S. health system may face similar scale challenges. During the Zika public health emergency some pregnant women in affected states found it hard to get tested, and pregnant women comprise only about 2% of the U.S. population.
In response to a congressional request, the CDC developed a PCR-based test for coronavirus that requires a laboratory, and these test kits have been authorized for emergency use by the FDA. But it’s easy to imagine the demand for test kits outstripping the supply, like it has in China. However, news in the United States suggests there were some early problems with CDC’s tests so they could only be utilized in a dozen out of over 100 public health laboratories across the United States.”
If made a priority, point-of-care diagnostic kits could be developed within months at a cost of tens of millions of dollars. Several companies are racing to develop one, but they need help to succeed. These include new diagnostic tools identified by the Foundation for Innovative Diagnostics, a 15-minute test being developed by Chinese laboratories, a Duke University test being deployed in Singapore, and diagnostic tests using CRISPR technology. These efforts still need more money flowing, robust competition, and coherent government coordination and management.
While development of diagnostic kits is less complex and expensive than creating new vaccines, it still requires testing and validation. The U.S. Food and Drug Administration (FDA) has an accelerated pathway for “emergently needed” diagnostic tools, but relies on developers to submit results from clinical validation studies that the developers need to conduct or sponsor themselves.
As was the case with developing point-of-care diagnostic kits for Ebola and Zika, developers of one for coronavirus may face hurdles to obtain clinical specimens from the CDC and local health authorities. These are needed to validate their tests in order to obtain FDA authorization.
In the absence of a standard methodology for quickly and confidently conducting these evaluations using sufficient number of clinical specimens, agencies such as the CDC or the World Health Organization (WHO) may question the accuracy and conditions under which those results were achieved, stalling their deployment (even after FDA emergency authorization is granted on the basis of developer-conducted clinical evaluations). This is exactly what happened during Ebola. A rapid diagnostic kit that showed promising results as early as October 2014 was not authorized by the FDA until January 2015, and its performance was unclear until June 2015, when field tests were published. Although it was fast-tracked, it was never used in the field during the peak of the Ebola epidemic.
Given that the U.S. government has both expertise and needed budget to develop rapid, point-of-care diagnostic kits for coronavirus, it should take the lead in doing so. It needs to charge a single agency, task force, or executive structure to spearhead this effort and remove unnecessary impediments — one that’s similar to a pandemic directorate that Ron Klain, President Obama’s “Ebola czar,” recommended be created inside the National Security Council. It should be empowered and held accountable for proactively fast-tracking the development of new diagnostic kits.
We also need “grand challenge” prize grants (e.g., $100 million) to incentivize these efforts in the private sector. Without sufficient incentives, many developers and companies will deem the investment needed to develop diagnostic kits too much of a financial risk.
To develop a widely accessible, inexpensive point-of-care diagnostic kit requires an accountable leadership, decisive science-based governance, significant financing, and the application of reliable principle-based scientific protocols to determine whom to test, how to interpret results, and how best to treat and quarantine those infected. Taking these actions now cannot only greatly help contain the current Covid-19 epidemic; it can also create a system for developing similar tools to stop future pandemics. By taking the lead in creating such an infrastructure, the United States can help itself and the rest of the world.