Professor Mark Ferguson:

I will do my best to explain the differences. A rapid antigen test detects a protein on the virus and it works where, in the test kit, there is an antibody that binds to that protein, and that is then linked to some sort of marker, whether it is a fluorescent marker or a gold marker, and it reads out as a little line. In simple terms, it is a lateral flow antigen test and it is predominantly detecting the presence of live virus of proteins that are in the intact virus. That is the basis of most pregnancy tests so, for many years, people have been able to walk into a chemist shop and buy a pregnancy test, which is a lateral flow test that works in that way.

What is great about this is it does not require a laboratory or any special equipment. It is a kit which anybody can use on their own or under supervision. By contrast, LAMP testing requires a laboratory, but unlike PCR, it does not require very sophisticated equipment or chemicals. It only requires an oven. For LAMP testing, one mixes the reagents and then tests the sample and it reads out, but this has to be done in a laboratory. It is slightly more accurate than a lateral flow antigen test and it might be suitable, for example, for a large company with, say, 2,000 employees or for those with access to a basic laboratory facility. LAMP testing is being used in some of the universities, such as Trinity College Dublin, for testing students. It is faster than PCR and slightly more accurate than lateral flow antigen testing, but in simple terms, it requires a dedicated person and a laboratory.

Our report focuses on the lateral flow antigen testing because ultimately, as rightly stated by the Deputy, people can do the test themselves. People can be trained to do it at home and, where a test is positive, the person would not go to work, but would have a confirmatory PCR test from the HSE. That is very much the strategy that the UK and other countries such as Austria, are pursuing. In the United States, there are big programmes under way as well and other countries such as the Czech Republic, Slovakia and so on are empowering their citizens to take ownership of their health and test themselves and, if they test positive, to go for a confirmatory PCR test. These tests are not quite as accurate as PCR. The false positive rate is approximately 1 in 1,000, which means that from every 1,000 tests carried out there will be a positive that is actually a negative. The order of accuracy in regard to the negative results, in other words where the test reads negative but a person is actually positive, is between 50% to 80%.

A really important point made in the report is that validated tests only should be used, a list of which are available on the EU Joint Research Centre website. Those are tests that have been validated by at least one member state and in use by at least more two member states and they meet certain minimum specificities. There are certain commercial tests that do not work nearly as well as I have articulated. They should not be used. People should use only those tests on the validated list.