Development and validation of a simple cellular immunity test (SCIT) for SARS-CoV-2 (Covid-19)

随着当前Covid-19冠状病毒大流行的展开，我们迫切需要筛查工具来确定谁感染了导致该疾病的SARS-CoV-2病毒。为了使人口和经济恢复正常，重要的是要知道谁已对该病毒免疫。这包括已经被感染的人，在某些情况下，他们没有意识到这一点。为了获得对SARS-CoV-2的免疫力，个体必须产生足够的免疫反应，以保护自己免受未来的感染。这可以通过在血液样本中寻找与病毒特异性结合的抗体来测量。许多公司已经尝试制造出一种测试方法来确定一个人的血液中是否存在这些抗体。然而，正如广泛报道的那样，所有这些测试都没有达到可靠性标准，因此没有被批准广泛使用。这类测试的技术障碍可能会继续阻碍它们的使用。我们建议采用一种不同类型的免疫测试，利用现有的实验室测试。对病毒的长期保护不仅来自抗体，还来自免疫系统中被称为“T细胞”的细胞，它在控制和根除病毒感染方面发挥着关键作用。从一管血液中，我们可以识别出对SARS-CoV-2病毒有反应的T细胞的存在。这种方法在确定免疫力方面可能比抗体测试更敏感，但这需要在已经从Covid-19中恢复的患者身上进行验证。我们在加的夫威尔士大学医院的长期临床同事（Andrew Godkin教授和Paul Morgan教授）将招募患者，以确定实验室检测这些T细胞的存在是否是抗体测试的可行替代方案。这种替代方法将提供关于个人是否感染病毒并对其产生免疫力的相同信息。此外，当疫苗确实可用时，这里开发的测试结果将提供关键的额外信息，以确定是否产生了保护个体免受SARS-CoV-2感染的充分免疫反应。到目前为止，这项资助成功地确定了一个人是否拥有对SARS-CoV-2病毒有反应的T细胞，“影响扩展”资助将为招募更多的人参与这项研究提供必要的支持。这将提供更大的数据集，并提供获得MHRA批准、CE标志和进一步验证所需的必要信息，从而使该测试能够商业化。了解他们的免疫状况将对那些目前生活在是否感染病毒的焦虑中的“脆弱”群体产生巨大影响。向疫苗制造商提供这种测试还将使他们能够评估目前正在开发的疫苗的长期成功。

As the current Covid-19 coronavirus pandemic unfolds, we urgently require screening tools that determine who has been infected with the SARS-CoV-2 virus which causes the disease. To enable the population and the economy to return to normal it is important to know who has become immune to the virus. This includes individuals who have already been infected, in some cases without realising it.In order to gain immunity to SARS-CoV-2, an individual must generate an adequate immune response that protects from future infection. This can be measured by looking for antibodies found in blood samples that bind specifically to the virus. A number of companies have attempted to manufacture a test that determines whether an individual has these antibodies present in their blood. However, as widely reported, all these tests have failed to meet reliability criteria and thus have not been approved for widespread use. Technical hurdles with this type of test may continue to hold up their use. We propose a different type of immunity test, utilising existing laboratory tests.Long-term protection against viruses not only comes from antibodies, but from cells of the immune system called 'T cells', which play a critical role in controlling and eradicating viral infections. From a single tube of blood, we can identify the presence of T cells that respond to the SARS-CoV-2 virus. This approach is potentially more sensitive at determining immunity than antibody testing, but this needs verifying on patients that have recovered from Covid-19. Patients will be recruited by our long-standing clinical colleagues at the University Hospital of Wales, Cardiff, (Prof Andrew Godkin and Prof Paul Morgan) to determine whether a laboratory test for the presence of these T cells is a feasible alternative to the antibody test. This alternative approach would provide the same information about whether an individual has been infected with the virus and generated immunity to it. In addition, when a vaccine does become available, results from the test developed here will yield critical additional information as to whether an adequate immune response that protects individuals from SARS-CoV-2 infection has been generated.Following on from the success of the grant so far in determining if a person has T cells that respond to the SARS-CoV-2 virus from just tube of blood, the “Extension for Impact” funding will provide the necessary support to recruit more individuals into the study. This will provide a larger data set and provide the necessary information required to gain MHRA approval, CE markings and further validations of the test, thus allowing the test to be commercialised. Knowing their immune status will have a huge impact on those people in the ‘vulnerable’ category currently living with the anxiety of whether they have had the virus. Making the test available to vaccine manufacturers will also enable them to assess the long-term success of the vaccines currently in development.