A range of COVID-19 tests are being used across Europe. Read our guide to the most widely used including the Antibody, PCR and Antigen tests – explaining exactly what they do, how much they cost and how accurate they are.

ANTIBODY TEST

When the immune system is exposed to COVID-19, it produces IgG antibodies to fight the virus. A COVID-19 antibody test looks for IgG antibodies in a blood sample – if present, that means you have had the illness. Studies have shown antibodies are produced approximately 14 days after the start of the illness, so the best time to take the test is 14 to 21 days after feeling unwell.

What does a positive result mean?

A positive result means you have been exposed to the virus and your immune system has produced antibodies in response. A small number of people may have had the virus and produced antibodies without ever feeling unwell, meaning they are asymptomatic carriers. 

What does a negative result mean?

A true negative result means the immune system hasn't produced antibodies because you haven't been exposed to the virus. However, a false negative is when you have been exposed to the virus but antibodies haven't been identified, either because the test was taken too soon or the body simply hasn't produced antibodies to fight the virus.

Is the test accurate?

The Roche antibody test widely used in the UK is 100 percent accurate in identifying IgG antibodies and 99.8 percent accurate in determining that there are no antibodies in the bloodstream. However, the timings of the test (pictured above) mean false negatives can occur, so it's imperative the test is taken within the 14-to-21-day window for optimal accuracy.

How much does it cost?

In the UK, only certain people who work in social care in England and Wales are able to get an antibody test for free. Otherwise, they must be bought at private clinics, with prices starting at $84. In Germany, the same test costs $76.

How long will it take to get my results?

Results typically take up to 72 hours from private health services.

POLYMERASE CHAIN REACTION (PCR) TEST

The PCR test is used to detect whether the COVID-19 virus is currently present in your body. This is done by looking for evidence of the virus's genetic material, known as RNA, from a swab sample taken from the nose and back of the throat. 

In the lab, a reagent is added to the sample – if the RNA is present the reagent sparks a chain reaction so it is visible to scientists, who can then correctly identify a positive test. The test is also commonly referred to as an RNA, genetic, molecular, viral detection or swab test.

What does a positive result mean?

The virus is currently present in your body, meaning you will have to self-isolate and take other necessary precautions advised by your national healthcare provider.

What does a negative result mean?

You don't have the virus or you have received a false negative reading. The ideal time to take the test is eight days after being infected, which means there is enough genetic material to produce a positive result. If there isn't, you may receive a negative result despite being in the early stages of infection.

Is the test accurate?

PCR tests vary in accuracy. Some can be as low as 70 percent accurate, as outlined here by Oxford University Hospitals in the UK. However, FIND (Foundation for Innovative New Diagnostics), tested five COVID-19 RT-PCR tests and found that all five achieved 100 percent specitivity on positive samples, and at least 96 percent specificity on negative samples.

How much does it cost?

Most European countries have made PCR tests available for free, though foreign nationals entering many EU countries have to pay. Travelers landing at Germany's Munich airport are being charged $213 for a PCR test.

How long will it take to get my results?

Between 12 and 24 hours but new technology available in some hospitals and medical practices can return results within just four hours.

ANTIGEN TEST

Similar to PCR tests, antigen tests also attempt to find out if you currently have the virus, but the process is slightly different. Rather than looking for the virus's genetic material, an antigen test looks for the presence of proteins or glycans, such as the spike proteins found on the surface of the coronavirus, via a swab sample taken from the nose and mouth.

What does a positive result mean?

The virus is currently present in your body, meaning you will have to self-isolate and take other necessary precautions advised by your national healthcare provider.

What does a negative result mean?

You don't have the virus or you have received a false negative reading. The ideal time to take the test is eight days after being infected, which means there is enough genetic material to produce a positive result. If there isn't, you may receive a negative result despite being in the early stages of infection.

Is the test accurate?

Antigen tests are typically very fast and cheap in many countries but are not as accurate as PCR tests, with some experts claiming they could miss 15-20 percent of infections when only small amounts of proteins or glycans are present. 

How much does it cost?

Private UK test centers charge up to $173, while in France, they are available in pharmacies for as little as $15.

How long will it take to get my results?

Antigen tests are the fastest of the COVID-19 tests, with some producing results in just a few minutes.