COVID-19: Dry-swabs and spit could help scale testing, and other top science stories of the week

On Wednesday, it was announced that in the largest and most rigorous clinical trial yet, patients taking the experimental drug remdesivir recovered from COVID-19 more quickly than those on a placebo. The drug works by interfering with the virus’s ability to replicate in the body. Trial participants that took it recovered in 11 days on average, compared to 15 days for those taking a placebo. There was no statistically significant reduction in mortality for the group taking remdesivir.

Anthony Fauci, director of the US National Institute of Allergy and Infectious Disease (NIAID) said that remdesivir would now become a standard treatment for COVID-19 in the U.S.

However, questions on remdesivir’s efficacy remain following contradictory results in a smaller study in Wuhan, China that showed no statistically significant clinical benefit for COVID-19 patients taking the drug. These results were published in prestigious medical journal The Lancet hours after the US announcement on Wednesday. However, the Wuhan study stopped early due to difficulties in recruiting participants, making the two trials hard to directly compare.

Some commentators suggest that results from the global clinical study coordinated by the World Health Organisation are required before a clear picture of remdesivir’s efficacy can be formed.

Meanwhile, the drug’s developer, Gilead Science Inc, is ramping up production and hopes to produce enough remdesivir to treat more than a million people by December 2020.

Other anti-viral drugs continue to be tested and will be necessary in both the short and long term to ensure enough supply and protect against the risk of SARS-CoV-2 developing antiviral resistance.

Early findings from a team at the University of Washington indicate that a simplified testing process could help boost the capacity of COVID-19 testing at a time when supply chain restrictions are hindering rapid scaling of conventional methods.

Using a small sample size of 11 pairs of tests, the researchers compared two testing workflows. Their new, simplified method correctly detected viral RNA in 9 out of 11 samples whereas the conventional method gave positive results in only 8 of the 11.

Usually, a coronavirus test is performed by (1) collecting a sample by taking a swab of the back of the throat, (2) storing the sample in a chemical solution during transport to the lab, (3) processing the sample to extract viral RNA and (4) measuring the level of viral RNA. The simplified workflow eliminates steps 2 and 3 by transporting the swabs dry and then directly measuring the level of viral RNA using a more readily available chemical solution.

While more and larger studies are needed to verify these initial results, they offer encouraging signs for how testing could be scaled to the levels required to begin safely relaxing social distancing measures.

In an unrelated study, a group at the Yale School of Public health have shared initial results (as yet not peer reviewed) indicating that saliva could be used instead of throat swabs to test for the virus that causes COVID-19. If confirmed, this could further help increase testing availability as the long swabs used to collect samples from the back of the throat are also in short supply.

Separately, the U.S. National Institutes of Health (NIH) announced on Wednesday a US$1.5 billion initiative to accelerate breakthroughs in virus testing. The goal of the program is to increase the capacity of the U.S. SARS-CoV-2 testing by 100 times by the end of the summer.