One of the most potent weapons for combating coronavirus – Educators, Pupils and Parents enlisted to pull out of the pandemic – in the biggest antigen testing experiments of any generation.
By Professor Chris Imafidon – The national strategy is testing both the ill and apparently healthy individuals (asymptomatics) so that we can effectively combat the coronavirus by potentially reducing the R-value or spread of coronavirus. So, schools and colleges were sent 57 million test kits ahead of their re-opening so that each student gets tested three times in school and twice weekly at home.
In order to conquer coronavirus, it is essential to know how many people are becoming infected, who are the ‘super-spreaders’, where (location), when and how of the infection. This is why testing for the virus at every stage of the disease is one of the most important priorities in suppressing spread. Different types of tests can confirm who might be currently infected with the virus, who might have been infected in the past and, who might need to be in strict isolation to stop the virus spreading. Current statistics shows that as high as 30% of covid-19 patients are totally asymptomatic, or unaware of their illness.
TESTING Vs TYPES
Scientists and clinicians have universally agreed that the ability to detect the virus is perhaps the single most important priority in fighting the pandemic. Therefore, there are many novel techniques, such as loop mediated isothermal amplification, next generation sequencing (LamPORE), point-of-care PCR, and lateral flow tests available or in different stages of development, re-designing, re-development, validation, and approval. Each has its own unique advantages and disadvantages. The preference of one type of test over another depends entirely on the primary intention for testing, and context.
There are several types of tests, the first type usually a nasal swab test for the presence of the virus to find out if an individual is currently infected even if there are no obvious signs or symptoms of the disease and the individual looks and feels perfectly healthy. If positive, then the person can be isolated and treated if necessary and all contacts traced and tested. So, that covid-19 can be stopped from spreading. World class leading lady Scientists, such as Professor Nwadiuto Esiobu of Florida are still researching various solutions in multi-disciplinary and international efforts.
PCR
Governments have invested resources in scaling up testing capacity in their responses to covid-19. Real-time reverse transcription Polymerase Chain Reaction (PCR) was the first, and still the most widely used, test. However, it takes several days between requesting a test and getting results. This then delays any possible decisions on treatment if needed. This unnecessary delay gives room for the infection to spread. A more serious consequence is that people may transmit infection before experiencing symptoms —a real driver of spread. In addition, some people who remain “healthy” have the same number of viruses (viral load) to those who develop symptoms and may also innocently contribute to spread.
Due to the impact of these delays, the importance of pre-symptomatic or pauci-symptomatic (subclinical) transmission, measures that shorten the time between testing and results are essential for reducing avoidable transmission. It is difficult to arrest unintentional spread of covid-19 with large scale PCR testing. But current PCR equipment is too large and requires a dedicated laboratory.
ANTIGEN TESTS
In contrast with PCR, Lateral flow (antigen) tests such as the ‘Siemens Clinitest kit’ can detect infectious (live viruses) cases in minutes. It can be scaled up quickly for location-based testing. They are inexpensive, do not require laboratories, and produce results in minutes and the testing staff requires very little training. This is essentially used for widespread community testing intended to reduce transmission or time spent in isolation. It is therefore excellent in enabling economic and social activities to re-open. However, Antigen, or Lateral flow tests are less sensitive than nucleic acid amplification tests such as PCR, generating more false negative results. It is really a good test of infectiousness rather than infection. Reliability of tests is very susceptible to sampling quality. Based on recent Oxford studies, the rapid tests are useful for screening because it provides opportunities for early detection and isolation. These pregnancy-style antigen tests produce results on the spot, unlike the standard nose and throat swabs which must be sent off to a huge laboratory miles away and takes days to get any outcomes. The speed is its strength, but the reduced accuracy means that it detects about half to three quarters of positive cases. This is still useful in a community-based setting so that some cases are identified before people develop symptoms or for those individuals who do not develop symptoms. This is why important governments and institutions embrace it.
Rapid antigen lateral flow tests such as CLINITEST are now effective screening alternatives. Although not advisable, some see a single test as a way to free an individual from quarantine obligations. It has been reported that repeated lateral flow testing has value when combined with other strategies. Recently, in Liverpool, UK, the government authorities examined test-to-protect, test-to-release (from quarantine), and test-to-enable (safer return to restricted activities) regimens, alongside outbreak response and public open access to antigen tests. This British trial demonstrated that rapid tests broke the chains of transmission, and influenced behaviour. According to Health Secretary, Mr Matt Hancock, mass asymptomatic testing (testing of apparently normal people) in the Liverpool experiment showed a case rate drop (R-value decrease) more sharply with mass LF tests than it did in other similar areas where only restrictions were brought in.
Another study by the University of Oxford and Public Health England found lateral flow tests are ‘sufficiently sensitive’ to detect the ‘majority’ of cases that lead to onward transmission of covid-19.
BLOOD TEST
Another type of test discovers if a patient has suffered in the past and whether that person might now have some protection from a second episode. This test achieves this by searching for antibodies in the blood. There are always traces of the antibodies, which the immune system uses to fight off viruses. Unfortunately, reliable antibody tests are not yet widely available while they are being trialed in various places and there are some pretty ineffective products in the market.
Researchers are busy getting a very reliable antibody test that can be mass-produced. If some immunity can be confirmed, it should be easier for those who test positive to get back to work. Once it is established that a significant population has some immunity it should be easier for us to lift lockdowns. As at today, there is no definitive evidence demonstrating that the presence of antibodies may provide some immunity. So, testing can help us put other data like the number of confirmed cases or a number of deaths into context.
TENSION
Most clinicians are unhappy with the accuracy of the Lateral Flow tests. But they detect the presence of antigen, or proteins produced by the body in response to the virus in mainly asymptomatic persons (with high viral load). So, it has a role to play as a non-clinical test. Dr David Eyre, who co-led the study at Oxford’s Big Data Institute, states clearly that ‘When the time comes to relax the current lockdown restrictions, by rapidly identifying the most infectious people using these lateral flow tests, we can potentially relax the lockdown much more safely.
TRACKING
Monitoring the developments and constantly reviewing the new data from all locations, and responses from different regions is needed in conquering the corona pandemic. All households or families with children of school age should get two free rapid COVID-19 (Antigen) tests per person per week. Families and households with primary, secondary and college age children, including childcare and support bubbles, will be able to test themselves twice every week from home as schools re-opens. This will assist in finding more COVID-19 cases and break the chains of transmission. Twice-weekly free testing will also be offered to adults working in the wider school community, including bus drivers and after-school club leaders.
Therefore, all 3.4 million state schools and private institutions have received 57 million test kits. The test results’ monitoring will need a national effort bigger than the current vaccination exercise. NASA inspired #covid pass a novel technology designed by Engineer Isaac Udutong, with innovative roots in Silicon Valley, California springs to mind in effective monitoring. There are additional technologies that are proven to assist in this area. They include the American-African jointly developed FireFlies. An online meeting tool used during outbreaks or lockdowns. Other testing technology of miniaturization of PCR in the northern UK led by Black researchers.
TRIUMPHS
Professor Tim Peto, of University of Oxford and senior author on the study, believes that ‘We know that lateral flow tests are not perfect, but that doesn’t stop them being a game-changer for helping to detect large numbers of infectious cases sufficiently rapidly to prevent further onward spread.’ Therefore, it is understandable for the government to deploy mass testing in schools in order to reduce the risk of spread of the virus. All secondary school pupils have been offered three tests on their return before being asked to carry them out twice a week at home.
TOMORROW
Based on the results of a quarter of a million people who participated in the antigen tests, future governments must work on the clear evidence that such tests are excellent in easily identifying the most infectious individuals in any community. Antigen tests should be deployed in combination with existing tests in determining people who may not have symptoms and are therefore not eligible for a test through the standard Test and Trace protocol. With this, it becomes easy for ‘super spreaders’ (most infectious individuals) to be identified earlier. Thus, potentially preventing onward transmissions and helping to drive reproduction numbers (R-value) below 1. So, rapid antigen testing is the best opportunity for early detection and isolation thanks to its speed and ease of use.
If you are an educational institution and have not received your lateral flow testing kits, please click on this website:https://www.gov.uk/government/news/all-households-with-children-of-school-aged-to-get-rapid-covid-19-tests-per-person-per-week
Professor Chris Imafidon, is a world renowned adviser to monarchs, governments, presidents and corporate leaders; multi-Guinness World Recorder holder; Mentor to New York Times Bestellers and a Sunday Times Op-ed author. [Twitter @ChrisImafidon; Instagram @CoImafidon; Facebook/Linkedln –Professor Chris Imafidon]
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