RE: FT Opinion: @Even with a vaccine, fast Covid tests will be crucial"10 Nov 2020 18:26
The best alternatives are lateral-flow, or rapid-antigen, tests, which work similarly to home pregnancy tests. They are cheap, easy to self-administer, give results in 15 minutes and do not require labs. The most pandemic-appropriate of these are paper-based tests, designed to turn positive when someone is contagious. Such “strip” tests could be deployed cheaply and at scale to allow frequent home testing.
Some oppose these tests on the grounds that they are less sensitive than PCR. But that misses the point. A test that is fast and can be used frequently is more useful than one that is highly sensitive. Reduced sensitivity is actually an advantage, returning positive results only in those with sufficiently high levels of virus that they are a risk to others. PCR tests can be positive for weeks.
At a minimum, rapid strip tests could be used to create Covid-19-free spaces through negative-test screening. In Germany, rapid tests are being used to permit safe visits to loved ones in care homes and hospitals. In the UK, Durham university is piloting self-administered swab rapid tests.
In the US, the performance of rapid tests on residential college campuses builds confidence. Mr Biden has said it will be a priority to scale up testing capacity “by many orders of magnitude” including with home tests and instant tests. In Madrid, where rapid tests have been used for several weeks, the case rate now seems to be falling faster than the rest of the country. Rapid antigen tests can also be readily adapted as new strains show up, such as has been seen in minks in Denmark.