Lessons learned during the COVID-19 pandemic

Since the onset of the COVID-19 pandemic, diagnostic testing has been an important component of the public health response. Of the two different types of diagnostic tests available – molecular and antigen – the level of precision of molecular polymerase chain reaction (PCR) tests is decidedly hard to beat.

While rapid antigen diagnostic tests deliver a quick turnaround for results, the tests’ precision is limited. The findings of a comparative sensitivity evaluation for 122 CE-marked rapid antigen diagnostic tests show that the sensitivity of the tests varied and 20% of the tests evaluated failed to meet the minimum sensitivity requirement.

In comparison, point-of-care (PoC) and small machine-based PCR tests are highly sensitive and precise. While standard PCR tests require that samples be sent to a centralized laboratory, often leading to at least a 24-hour wait for results, PoC and small machine-based PCR tests reduce the sample-to-answer turnaround time by providing results in 20-40 minutes.

The multiplexing capabilities of PCR tests also allow for the detection of other potential infections, making them ideally suited for schools. Although more expensive, costs can be minimized by performing testing using pooled samples to increase the number of people who can be tested using the same amount of resources.

Plus, as vaccination rates increase, the viral load of individuals infected with COVID-19 is lower. Only PCR tests can detect such low viral loads in an acceptable manner. As a result, PoC and small machine-based PCR tests should be considered the method of choice, both now and in the future as we continue to navigate the pandemic.