Four Things to Know About COVID-19 Testing

You do not have to travel far in the UK today to catch a glimpse of COVID-19 testing signage at major and minor testing centres across the country. As authorities continue to push for more extensive testing as the single most important weapon against Coronavirus transmission, more people than ever before are getting tested.

Nevertheless, there is still a great deal of misinformation and confusion about certain aspects of the COVID-19 testing process. To help clarify a few important points, here are five things you need to know about COVID-19 in the UK:

1. PCR and Antigen Tests Work Differently

Antigen tests - aka rapid tests - are being performed by millions of people across the UK each day. However, antigen tests are only considered accurate when the individual in question has a particularly high viral load. Consequently, a negative result on an antigen test is not considered reliable - particularly if the individual in question is experiencing COVID-19 symptoms.

By contrast, PCR tests are considered to have an accuracy rate of close to 100%, if performed by a suitably capable professional.

2. You May Need to Have Both Tests

Increasingly, doctors are advising patients who have taken an antigen test to subsequently take a PCR test. If the antigen test is positive, a PCR test may be recommended to confirm a case of COVID-19. If the antigen test is negative, a PCR test may be recommended to confirm that it was not simply a false negative.

This is why where possible, doctors and health experts advise taking the PCR test over the antigen test, due to the potential for the latter to produce unreliable results.

3. Vaccinations Will Not Cause Positive PCR Test Results

There have been numerous instances where individuals vaccinated against COVID-19 have subsequently tested positive for the virus. However, the vaccination itself cannot in any way influence the outcome of a professionally administered PCR test. If the test result is positive, the individual either contracted COVID-19 prior to being vaccinated, or shortly after receiving the vaccine.

Evidence suggests that antigen test results may be affected by recent vaccination, therefore once again are not considered a particularly accurate testing method for those who have recently been vaccinated.

4. A Positive Test Result Should Never Be Ignored

Lastly, there are no instances where a positive test result should be ignored.  Even where an individual is demonstrating none of the signs or symptoms of COVID-19, a positive result on either an antigen test or a PCR test should be regarded as accurate and the necessary steps taken to prevent transmission of the virus.

In the case of a negative antigen test, a PCR test can subsequently be taken to verify the result. Where a PCR test is positive, it is considered as close as possible to 100% accurate - if administered by a suitably qualified professional.