Since the start of the pandemic more than a year ago, I have proposed several times through the Brussels Times the creation of an immunity passport to allow people who have natural immunity through contracting the illness to resume their normal activities without risk to themselves or society.
Over the last year, scientific data has given ever greater assurance that those who have been ill with Covid-19 are able to achieve a lasting recovery. Relapses are extremely rare and require verification. This shows that those who have been ill no longer carry the virus and so are not contagious.
This has crucial implications in terms of health, the economy and society. The numbers of those who are recovered and are not contagious mechanically increase with the progression of the pandemic. In fact, the number of recoveries – which are more or less spontaneous in the great majority of cases – closely tracks the number of infections with a delay of a few weeks. About 98% of people recover from Covid-19 without too many problems in two to three weeks and so acquire natural immunity.
Global recoveries 142 million
Official statistics as of May 17 compiled by Worldometers show a global total of 164 million infections and 142 million recoveries. This has practical implications which would be a serious error to ignore.
I will concentrate on France, where I currently live in exile from my native Cambodia.
The Institut Pasteur estimates that the number of people in metropolitan France who have had Covid-19 is above 9 million,considering only adults over 20. This compares with the official total of recorded infections of 5.8 million. Those who have died or are still suffering from the illness number about 800,000, bringing the number of full recoveries to 5 million. This means that more than 4 million people in metropolitan France have been infected by SARS-CoV-2 and then recovered from Covid-19 without knowing and/or declaring it.
When I started arguing the case for immunity passports for those who have recovered early last year, no-one dared to hope that a vaccine against Covid-19 would be developed so fast. Mass vaccination campaigns starting early this year mean that the struggle against the pandemic has entered a decisive phase. However, the idea of an immunity passport retains its importance as a practical recognition of immunity.
This immunity can either be natural, following contraction of the illness, or induced by vaccination. Those who have either form of immunity do not present the same risks as those who have no immunity. This leads to the problem of confinement or other restrictions on freedoms being imposed with no consideration for immunological status and the risk of contagion that each individual presents. I addressed this problem in a previous opinion piece in the Brussels Times on April 10 entitled “Covid-19: Governments must stop treating everyone the same.”
We have obtained a first victory as on May 6 the Conseil d’Etat recognised that the available science shows that “people who have suffered from Covid-19 and then recovered are almost certain not to carry the virus for a period of at least three months and probably six months”, and so present a very low risk of contagion during this period. The risk is in fact logically zero as you cannot pass on a virus which you do not have yourself.
The fact that the Conseil d’Etat did not order any modification of the rules in place is for administrative reasons concerning the capacity of the police to verify, across the whole of France, the immunological status of those who leave home during curfew hours.
From the “vaccine passport” to the “health pass”
As vaccine campaigns advance, pressure from the public and business for the creation of a “vaccine passport” showing that the holder is immune and non-contagious, is increasing. Such a document, especially in a standardised electronic form, would allow international travel and tourism to recover in secure conditions for all.
When it comes to the aim of reopening society, the term “vaccine passport” is too restrictive as it refers only to the immunity obtained through vaccination. This overlooks the immunity of those who have had the illness. The term “vaccine passport” is also unsuitable because even now the number of people in France who have had two injections (8.8 million as of May 16) is less than the number of people who have been ill and acquired natural immunity. This number stands at more than 9 million. There may be some overlap between the two groups, but the logic of the argument is unaffected.
So France has finally agreed with the European authorities, who in turn have learned from experience in Israel and Denmark, to prepare to launch a “health pass” in accordance with Europe’s “green certificate.”
In any case, the French “health pass” which is likely to become a reality in June, is a broader concept covering a wider population than a “vaccine passport” as it will be given not only to those who have been vaccinated but also to those who have had the illness. For the latter group, a positive polymerase chain reaction (PCR) test more than 15 days old is sufficient. If, since the virological test showing infection, the person has stopped having symptoms, or if the person never had symptoms in the first place, then they are considered as recovered. No other kind of test is needed.
The procedure to identify those who have been ill is in the end very simple, easier than I thought at the start. The science now shows that natural immunity involves more than antibodies and also includes memory T lymphocytes, or “killer cells”.
As the virus mutates, these T lymphocytes are a precious line of defence. Antibodies recognise only the proteins on the surface of a virus. These proteins are most capable of mutation which can render the antibodies ineffective. But some T lymphocytes are capable of recognising proteins on the inside of the virus, which are least able to mutate. So the T lymphocytes can continue to destroy infected cells despite superficial virus mutations.
Natural and vaccine-induced immunity
The pros and cons of natural and vaccine-induced immunity can be debated. I am inclined to favour natural immunity. Vaccines are no more than a manufactured response which seeks to replicate natural immunity. Such a copy can hardly be expected to be an improvement on the original.
Several of the formerly ill people in my association presented their medical records to the Conseil d’Etat. These showed that, several weeks or months after contraction of the illness as shown by a positive PCR, recovery was achieved, shown by the disappearance of all trace of the virus in the upper respiratory tract (negative PCR test) and the appearance of the IgM and IgG antibodies (positive serological test).
If the epidemic seems to have been contained and is starting to retreat in Europe, this is due not only to vaccination campaigns but also to the ever-growing number of recovered people who form a natural barrier against further spread, thus significantly contributing to “herd immunity.”
Recognising a specific immunological status for those who have had Covid-19 will also have significant consequences for heavily populated poor countries which will find it hard to acquire enough vaccines. Storing and classifying the results ofthe very first virological detection tests will, a few weeks later, allow those who have been ill to be identified without the need of any additional test or procedure. These people need the vaccines the least. Priority should be given to other, more vulnerable people who have not come into contact with the virus.