As its name suggests, the immunity passport is a document attesting to the immunological status of its bearer. The proof it gives of immunity and absence of contagion risks means that it can open the possibility of travel denied to others.
Further, the immunity passport allows its immune and non-contagious holder to resume their normal activities without risk to themselves, those around them or society as a whole.
In the pandemic’s early days in March 2020, seeing the danger of the world’s economy being paralysed, I set down the conceptual bases and rationale for the immunity passport in The Geopolitics: “How to Prevent COVID-19 From Paralysing the World’s Economy.”
The idea, I wrote, was to look at the other side of pandemic, that is to say the people who – most often without realising it – are not, or will no longer be, vulnerable to COVID-19 because they have become immune after catching the disease. Even then, it was clear that the number of such people would increase very rapidly, even in the absence of a vaccination. The priority, I argued, was to identify this population through a serological test to detect antibodies.
An immunity passport expanded to the vaccinated
With this article I became one of the first proponents of the immunity passport and I continued with the theme in 28 further articles in English and in French that have been published in The Geopolitics, The Brussels Times, The Kootneeti and Gavroche (2). I am heartened to see that the European Union is on the point of officially adopting the “COVID-19 Pass” or “Digital Green Pass” for its 27 member states. This is simply an expanded version of the immunity passport.
All the standardised travel documents being prepared in the context of COVID-19 – whether they are called “COVID-19 Pass,” “Digital Green Pass,” “Green Certificate” or “Health Pass” – attest to the immunity of the bearer, exactly like the immunity passport initially imagined. But the immunity of those who have had the illness must be expanded to include that of people who have been vaccinated.
Natural post-recovery immunity
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 point was not that clear only a year ago. In April 2020, the World Health Organization (WHO) advised against the creation of an immunity passport because there was “no evidence that people who have recovered and have antibodies are protected from a second infection.” The WHO must now revise its position because the situation has fundamentally changed since.
There has been an interesting development in France, where I live in exile from my native Cambodia. Following an application lodged on behalf of people who have recovered from COVID-19 to seek the lifting of restrictions on their liberties, the Conseil d’Etat – which has the power to rule in the final resort on claims filed against the state – recognised on May 6 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. In my view the risk is, in fact, logically zero. You cannot pass on a virus which you do not have yourself.
Several of the formerly ill people 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 polymerase chain reaction (PCR) test, 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).
The two pillars of collective immunity
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. This also means that we have to distinguish natural immunity acquired after contracting the illness and immunity induced by vaccination.
In many countries, even where a good part of the population has been vaccinated, natural immunity is still more widespread than vaccine immunity. In France, based on information from the Institut Pasteur, we can estimate that, as of May 18, naturally immune people (about 10 million) still exceed those who have had the required two vaccine doses (about 9 million).
Official statistics as of May 20 compiled by Worldometers show a global total of 166 million infections and 145 million recoveries. Such a total has crucial implications in terms of health, the economy and society given that the number mechanically increases 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.
In Europe, if the epidemic seems to have been contained and is starting to retreat, 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.”
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.
But 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, as pointed out above, even in many developed countries the number of people who are fully vaccinated is still lower than the number of people who have been ill and have acquired natural immunity.
In any case, the European “Health Pass” or “Green Certificate” 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 to both those who have been vaccinated and those who have had the illness, on an equal footing.
This means that natural immunity is considered as of equal quality to that of vaccinal immunity. It is interesting to note that such an appreciation definitely clashes with the WHO’s current reservations on natural immunity as elaborated above.
Easier identification of recoveries
To identify the recovered in the European protocol for delivering a “Health Pass” or “Green Certificate,” a positive 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.
Therefore the procedure to identify those who have been ill is very simple, easier and faster than I thought at the start, when a blood test to detect antibodies seemed to be necessary to confirm recovery and immunity.
The science now shows that natural immunity involves more than antibodies. These represent humoral immunity and can become impossible to detect after a certain time. But natural immunity also involves memory T lymphocytes, or “killer cells” which offer cellular immunity and longer-lasting protection.
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.
Lessons for Poor Countries
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. In such countries – which are still at the very start of their vaccination campaigns – natural immunity is still, by far, the strongest rampart against the spread of the coronavirus.
Storing and classifying the results of the 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.
The WHO has asked rich countries not to vaccinate children and adolescents and to give the doses that are saved to poor countries. Poor countries in turn must also manage, rationalise and prioritise vaccinations and avoid or delay using doses on the easily identifiable people who have already been ill and are already immune. Doing so is certain to save lives.
The views and opinions expressed in this article are those of the author.