The US health watchdog has authorised the emergency use of a new saliva-based laboratory diagnostic test for Covid-19 that could be a game changer in the diagnosis of the infection as it will enable rapid testing amongst more people easily. Stephen Hahn, the Food and Drugs Administration Commissioner, said the new saliva test would increase efficiency and avoid shortage of crucial test components like reagents. "Providing this type of flexibility for processing saliva samples to test for Covid-19 infection is groundbreaking in terms of efficiency and avoiding shortages of crucial test components like reagents," he said in a statement.
The agency has previously authorised four other tests that use saliva for sampling, but these yielded varying results. Authorisation of the new test occurs amid ongoing disarray over Covid-19 testing. The US has been plagued by an inconsistent strategy for detecting the virus, thanks in part to persistent shortages and the use of a variety of different tests that have sometimes yielded unreliable results.
The new method called SalivaDirect is being further validated as a test for asymptomatic in dividuals through a programme that tests players and staff from the National Basketball Association (NBA). SalivaDirect is simpler, less expensive and less invasive than the traditional method for such testing known as nasopharyngeal (NP) swabbing. Results so far have found that SalivaDirect is highly sensitive and yields similar outcomes as NP swabbing.
With the FDA's emergency use authorisation, the testing method is immediately available to other diagnostic laboratories that want to start using the new test, which can be scaled up quickly for use across the nation and, perhaps, beyond - in the coming weeks, researchers said. A key component of SalivaDirect, the researchers note, is that the method has been validated with reagents and instruments from multiple vendors.
This flexibility enables continued testing if some vendors encounter supply chain issues as experienced early in the pandemic. "This is a huge step forward to make testing more accessible," said Chantal Vogels, a Yale postdoctoral fellow,."This started off as an idea in our lab soon after we found saliva to be a promising sample type of the detection of SARS-CoV-2, and now it has the potential to be used on a large scale to help protect public health. We are delighted to make this contribution to the fight against coronavirus," he said.