More Antigen Testing?

In a pitch for more, faster antigen testing, Scott Gottlieb presents a status report on the campaign against SARS-CoV-2 in an op-ed at the Wall Street Journal which I will take the liberty of quoting in full:

The Covid-19 epidemic continues to expand in some 20 states. The number of new cases in New York City is slowing, but the picture is different elsewhere in the nation. America has hovered around 30,000 new daily infections and 2,000 deaths for almost a month. Yet the number of days it takes for infections to double has improved, from less than a week in hot spots to almost a month nationally. This represents progress.

But everyone thought we’d be in a better place after weeks of sheltering in place and bringing the economy to a near standstill. Mitigation hasn’t failed; social distancing and other measures have slowed the spread. But the halt hasn’t brought the number of new cases and deaths down as much as expected or stopped the epidemic from expanding.

Officials face intense pressure to reopen, and the reality is stark: Continuing spread at something near current levels may become the cruel “new normal.” Hospitals and public-health systems will have to contend with persistent disease and death.

Higher rates of spread may be limited to some areas; a majority of states have more than 250 new cases of Covid-19 every day. But as states begin to open up their economies and Americans return to traveling, the disease will continue to expand. We need to prepare to deal with such a grim future, which will require a persistent posture of prevention and treatment.

That means doubling down on screening and isolating sick people to slow the spread as much as possible, which will save lives and prevent health-care systems from being overwhelmed. That means channeling resources into places where outbreaks are prone to happen: nursing homes and shop floors, and among disadvantaged communities that lack access to testing and can’t practice social distancing easily.

Technology and a well-equipped and competent medical and public-health workforce will be essential. This includes better drugs. On Friday the Food and Drug Administration authorized the use of remdesivir by Gilead Sciences. This drug is the first antiviral medicine that blocks SARS-CoV-2 replication. It isn’t a cure, but it will help patients at highest risk of bad outcomes, especially when deployed early in the course of the disease. More treatments are likely to follow, including antibody drugs that bind and block the virus. These should be available this fall if progress continues apace.

A number of vaccines, meanwhile, are on track to clear early FDA safety trials by fall, and tens of millions of doses could be ready to use in studies that test for efficacy. These doses can be used in large trials that will establish whether the vaccine is safe and effective for mass inoculation, trials that can be conducted in cities suffering from outbreaks.

But the public also needs better diagnostic tests to make screening for Covid-19 inexpensive and routine. This is where medical progress has been slow. Testing so far has relied on detecting the nucleic acids of the virus’s genetic material. These platforms are reliable and were initially easy to expand. The U.S. medical system is now screening more than 1.5 million people a week. But these platforms can only run so many tests each day, and issues like transporting samples are precluding quick turnarounds.

What’s needed now is the equivalent of the rapid flu and strep tests available in a doctor’s office. These tests look for antigens that the pathogen produces, which betray its presence in blood and saliva. Antigen tests are less precise than polymerase chain reaction (PCR) tests, but they enable fast and widespread testing. The government needs to rush development of these technologies and work with manufacturers to increase capacity.

More-precise platforms like PCR will still have an important role. They’ll be used by big commercial labs that can run them at the scale needed to improve cost and efficiency. They’ll also serve as a reference standard and be used for mass screening by pooling many patients’ samples—say, in a workplace—and testing them all at once to see if anyone in the group is infected.

If the virus continues to spread, the economy won’t snap back. Many Americans will be scared to go out, and with good reason. Summer may provide some reprieve, but the virus could return aggressively in the fall. Activity can resume in parts of the country where risk is low, but there is still much disease and death in the days to come.

Dealing with this new reality will require screening to identify new cases and isolate infections. That will depend on better testing technologies that aren’t yet available—but can be achieved. The sooner the better for the health of Americans and the economy.

I think there needs to be more introspection about why the measures put into place since March have failed to live up to their advance publicity as illustrated in this sentence:

But everyone thought we’d be in a better place after weeks of sheltering in place and bringing the economy to a near standstill.

Even in the limited successes I see a lot of post hoc propter hoc reasoning being advanced. Is the slow decline in the number of new cases being reported in the NYC metropolitan area because of the measures that have been put in place, because of other changes, or because the disease is running its course?