Solving COVID: August 19, 2020

Scientists have been seeing "encouraging signs of strong, lasting immunity" to COVID-19, including in people who only experienced mild symptoms. Antibodies that fight the virus, and B cells and T cells that recognize it, appear to persist months after the infection has faded. "This is exactly what you would hope for," says University of Washington immunologist Marion Pepper, who authored one of the recent studies. "All the pieces are there to have a totally protective immune response." Emory University immunologist Eun-Hyung Lee adds: "Yes, you do develop immunity to this virus, and good immunity to this virus. That's the message we want to get out there." At the same time, it's still not clear how long the immune responses might last, and the recent studies "do not demonstrate protection in action." [The New York Times]

Kansas and Alabama have seen their coronavirus trends improve following mask mandates, The Wichita Eagle and AL.com report. One month after Alabama's mask order went into effect, coronavirus numbers are on the decline, whether it's the percentage of positive tests (which was down to 11.1 percent on Friday from a high of 16.7 percent on July 18), hospitalization, or the raw number of daily infections. Of course, social distancing and other hygiene measures have played a role, but the mask mandate — and, more importantly, compliance — seems to be paying off. Kansas provides an even clearer view of the effect masks have, since the data collected by the Eagle shows a contrast between counties that followed the statewide mask order and those that didn't. Overall, Kansas' rolling 7-day average of new infections is down from its peak in mid-July, and the pattern is reportedly holding true in 16 counties that adopted the mask order. In 89 counties without a mandate, cases have trended up recently. [The Wichita Eagle, AL.com]

Beta interferon, an anti-inflammatory drug that has already been approved for treatment of multiple sclerosis, is being paired with remdesivir in the latest phase of a federal coronavirus trial, The New York Times reports. The results of the study's second phase are still being evaluated — and scientists are hopeful. Beta interferon is already on the market, and has shown promise against the new coronavirus, killing it (along with the SARS and MERS coronaviruses) in lab studies. Additionally, tests in the United Kingdom and Hong Kong showed the drug performed better among COVID-19 patients than the placebo it was up against. Both those studies were too small to come away with anything definitive, but the U.S. trial should be large enough to get a better sense of its ability. [The New York Times]

Some infectious disease experts are examining the "hopeful possibility" that far fewer people than initially thought need to get infected or immunized with COVID-19 to achieve herd immunity, The New York Times reports. Researchers assumed that herd immunity would be reached with 60 to 70 percent of a population infected. But new models suggest it could be reached at 50 percent infection or less. "Mathematically, it's certainly possible to have herd immunity at these very, very low levels," Carl Bergstrom, an infectious disease expert at the University of Washington, tells the Times. "Those are just our best guesses for what the numbers should look like," but "they're just exactly that, guesses." It's not clear any city or pocket of a city has sufficient immune people to thwart a second wave of COVID-19, but there may be parts of Mumbai, London, and New York that are close or have developed at least significant collective resistance. [The New York Times]

The Food and Drug Administration issued an emergency use authorization for the SalivaDirect COVID-19 diagnostic test developed by the Yale School of Public Health. The test analyzes saliva samples to rapidly determine whether a person is infected with the coronavirus and does not require any type of swab or specific collection device. It could be one of the first "major game changers in fighting the pandemic," said Andy Slavitt, a former acting administrator of the Centers for Medicare and Medicaid Services under the Obama administration. The testing process is easier and more affordable than other options — materials cost about $4, Slavitt said, and even when adding the cost of labor and overhead, its development is still cheaper than current tests. Because it's cheap and has a fast turnaround time, people will likely be able to get tested more frequently, which could increase diagnostic accuracy. [FDA, Andy Slavitt]