It was reported on 13 May 2020 that Public Health England (PHE) has approved Roche’s Elecsys® Anti-SARS-CoV-2 antibody test (the Roche Test) for use in the UK government’s national COVID-19 testing efforts.
Antibody tests such as the Roche Test are designed to test for the presence of antibodies against a particular disease following a suspected infection. The presence of antibodies confirms that a person has had the disease in question, and may indicate that the person is also now immune to it. However, they cannot be taken as confirmation of immunity, particularly in the context of a virus such as COVID-19, about which so little is known.
Following evaluation by PHE, the Roche Test is reported to have 99.8% specificity for COVID-19, meaning it will very rarely falsely identify antibodies for other pathogens as COVID-19 antibodies, and 100% sensitivity, meaning it will detect all antibodies present in the sample on which the test is conducted. The Roche Test can also provide results in approximately 18 minutes.
PHE believes that the Roche Test will allow a reliable determination of whether a patient has already contracted COVID-19. However, home testing is not on the cards, as the Roche Test requires the use of a Roche cobas e analyser, which are usually only found in hospital laboratories.
Although unsuitable for home testing, the Roche Test represents a significant improvement over the much-touted finger-prick antibody tests which were purchased by the government in bulk and trialled by the University of Oxford last month. Those devices were found to have an accuracy of only 50-70%, resulting in frequent false positives and false negatives. It is being reported in the media that the Secretary of State for Health is now trying to obtain a refund for those devices.
The role of Public Health England
PHE is not a regulator, and the reported decision is not a regulatory approval. The Roche Test had already been CE-marked prior to being tested by PHE, meaning it had already met EU regulatory standards and could already be lawfully placed on the market in the UK and other Member States. The Roche Test was also granted an Emergency Use Authorisation by the FDA earlier this month.
Instead, the purpose of PHE’s testing was to evaluate the Roche Test to confirm that it works as well as intended. In a manner akin to its efforts to scale up ventilator production under the Ventilator Challenge, the government has published an ideal performance specification for antibody tests (the Target Product Profile) and issued a challenge to manufacturers to produce tests that meet that specification. The Department for Health and Social Care is responsible for assessing offers from prospective antibody test manufacturers, and evaluation by PHE is a part of that process.
PHE’s decision confirms that the Roche Test meets the Target Product Profile, and so is suitable for use in the government’s mass national testing efforts. It is reported that Roche is now in negotiations with the government to provide the Roche Test for use by the UK health authorities.
A route back to normal life?
Antibody tests such as the Roche Test have an important role to play in combatting COVID-19 in the UK. They should allow UK health authorities to confirm whether patients and the people with whom they have been in contact have already had COVID-19, which will be integral to the government’s “Test, Track and Trace” strategy for controlling the pandemic when the current lockdown is lifted. In time, we might also expect such testing to be rolled out to the public at large, enabling scientists to better understand how many people in the general population have had COVID-19.
However, until we develop a better understanding of COVID-19, a positive antibody test will not allow a recovered patient to resume their ordinary life under a form of “immunity passport”. This is because the presence of antibodies is no guarantee of long-term immunity against a disease, and it is still unknown whether or not previous exposure to COVID-19 grants any immunity to the virus, or how long such immunity might last. It is possible that having contracted COVID-19 in the past will not prevent you from getting it again, and that the development of an effective vaccine may be required before normal life can resume.
 In accordance with the In Vitro Diagnostic Medical Devices Directive 98/79/EC.