The acceptance by governments and business leaders of the validity of COVID-19 immunity testing has gathered pace as the prospects for the fast development of a vaccination recede.
COVID-19 will not go away once the worst of the pandemic is over and confinement restrictions are gradually eased. We will have to learn to live with it, and, for a considerable period, we will have to do so without a vaccination. The vaccination for Ebola took five years to develop, and those for other new illnesses have often taken even longer.
There is no guarantee that a vaccination for COVID-19 will ever be successfully developed. Even with work being accelerated and all possible resources thrown at the problem, the consensus among scientists is that a vaccination will take until mid 2021 at a bare minimum. It would then need to be produced and distributed on an unprecedented global scale, which will take more time.
All this, and in particular the need for global distribution, means that establishing and documenting immunological status, as I have argued in a series of articles for The Geopolitics, is not an option, but a necessity.
Political, business and civil society leaders have to devise ways to make society and the economy function in the meantime. We have to find a way out of confinement, and to avoid the risk of reconfinement: we can’t simply close down for a year or more. Two problems are now in the process of being resolved. These concern the reliability of serological tests, and the length of the immunity acquired by those who have had contact with the virus.
There has been a breakthrough in terms of testing reliability. Progress by British scientists means that it may be possible for people to test themselves as early as June. The tests, developed under the government-funded Rapid Testing Consortium programme at Oxford University, may cost as little as 10 pounds (US$12.40) a time. The challenge now is to scale up the manufacturing process: the consortium believes it could produce up to 1 million tests a week by the summer.
Institutions and companies in Europe have confirmed the viability of testing. In France, the Institut Pasteur has developed four highly reliable serological tests which totally avoid the problem of false-positive results, while another test from the start-up NG Biotech has been evaluated in hospitals and found to be able to test for antibodies with 98% reliability after a delay of 15 days. In Liege in Belgium, the ZenTech biotechnology company has devised a test that it says is 100% accurate and provides results within 15 minutes.
It’s certain that public health policies over COVID-19 will evolve as rapidly as scientific discoveries and technological progress, notably concerning serological tests before the arrival of a vaccination.
Measuring the window of immunity
The World Health Organization (WHO) has pointed to the possibility that people infected with COVID-19 might become ill, and contagious, again. For many of the other forms of coronavirus that existed long before COVID-19, the initial immunity of those who have been infected weakens after a few years.
There have been reports of people in China and South Korea who were believed to have recovered from COVID-19 apparently relapsing: this could be due to a new infection, a reactivation of the old infection or an inaccurate antibody test.
We do not yet know how long immunity to COVID-19 will last, but scientific understanding is advancing and will continue to do so. Regular, repeated testing for antibodies is the only way to find out what we need to know.
The table shown here indicates that the best logical approach is to combine virological and serological tests to cover all possible outcomes and ensure that the patient is not prematurely identified as immune.
Two successive Covid-19 tests are required for issuing an immunity passport. The first step is the polymerase chain reaction (PCR) virological test which allows candidates who are infected by the coronavirus to be immediately eliminated, whether or not they have symptoms. These are the people that public health authorities are seeking to identify so as to be able to isolate them and prevent propagation. The second step is the serological test to search for the IgM and IgG antibodies. This gives four different possibilities corresponding to the immunological status of the person tested. The procedure means that an immunity passport can be granted on the most solid grounds.
Like a regular passport, the immunity passport may need to be renewed. If it was established that the acquired immunity only lasts for a certain period, for example three months, then an immunity passport could be granted for that period. It’s reported that the UK government, following the example of many other countries, is planning to impose restrictions such as a fortnight of quarantine on all travellers. Even a short period of proven immunity has the potential to avoid such a necessity.
In the case of COVID-19, the infectious state or the immunity status of every person may quickly change. It can change for a person who is apparently “no risk” because they have tested “negative” in a virological test. This is likely to be faster than for another person who meets the criteria for an immunity passport after a “positive” result in a serological test. The first person could become infected from one day to the next, while the second has a greater chance of keeping their antibodies for longer along with their immunity which, in all probability, will not disappear overnight.
Chile is the first country to adopt immunity certificates for patients who have recovered, enabling them to become active and help their communities. The French company Veolia is the first large company in the world to have offered a serological test to all its employees to determine their immunity status. Veolia has 50,000 employees and the tests will cost it 15 million euros. The company says that the tests, which are optional, have been backed by unions. That’s no surprise: there is a growing popular demand in France for serological testing. According to an opinion poll by RMC, 94% of French people are in favour of serological tests being carried out in pharmacies, with 64% in favour even if they have to pay themselves. Government authorisation for pharmacy testing has not yet been given.
The urgent need is testing to identify the length of time for which a person can safely be counted as immune. To ignore or dismiss the window of immunity because we can’t yet measure it is to discard one of the few economic resources we now have. In terms of finally ending the pandemic, if and when a vaccination finally becomes available, using the window of immunity can make a decisive difference in the speed of its distribution. In the meantime, many of the practical problems of public health management can be solved by immunity passports, and a return to an active economy facilitated.
The views and opinions expressed in this article are those of the author.