PARIS — As governments strive to acquire vaccines against COVID-19 and launch vaccination campaigns in the midst of global uncertainty, a new idea seems to be gaining ground: an immunity passport.

These "COVID passports," we are told, could facilitate travel and trade. They would certify that a person has received a vaccine or has been infected by proving, for example, the presence of antibodies against the new virus.

This idea is not new. It stems from the passeport sanitaire, a 19th-century French invention (not without controversy) whose purpose was quite different. The holder of the health passport was considered "immune" in the medieval sense of the word (from the Latin immunis), i.e. "free" of symptoms until proven otherwise. Moreover, inoculation was not included on this document, whose purpose was rather to allow authorities to detect suspicious or reported cases, and consequently to extinguish any epidemic threat at French borders.

On June 18, 1890, in order to keep cholera — rampant at the time in Spain — from spreading in France, the Interior Ministry produced a memorandum asking prefects to issue travelers with a "health passport" and a "notification card" addressed to the relevant mayor. The mechanism consisted of having each traveler examined by a doctor and then reporting to the local authorities that the person had been "recognized as healthy" but had to remain "under medical supervision" during the incubation period. This health passport was, in addition to the "political passport," another French invention conceived in the 15th century initially to "pass" goods and quickly extended to people.

The WHO's "Yellow card" and a French Passport — Photo: Walid Berrazeg/SOPA Images via ZUMA Wire

It was during the 1893 International Sanitary Conference in Dresden that Adrien Proust — professor of health at the Paris Faculty of Medicine, chief physician at the Hôtel-Dieu and father of the novelist Marcel Proust — suggested that this procedure be used internationally. The Austro-Hungarian Empire had convened the conference in Dresden against a backdrop of cholera epidemics that were spreading more rapidly in Europe with the arrival of the steamboat. It was imperative to standardize international quarantine regulations against the spread of these new health threats.

For Adrien Proust, any epidemic was first controlled at the borders. He saw in the health passport a more targeted version of quarantine and the equivalent of "observation" at the lazaret (a quarantine location for sea voyagers). The health passport was thus a means of tracing people considered asymptomatic and isolating them in case they became symptomatic. The objective was to prevent "outbreaks" of infections, and this procedure made it possible to "act quickly and effectively" — before it was too late.

Preventive inoculation, on the other hand, was only possible for the plague, and was only recommended for those most at risk (such as personnel disinfecting ships). In addition, Proust considered inoculation to be less effective than strict "sanitary surveillance" for several reasons. First, it was not mandatory; second, it did not protect infected but asymptomatic people; and third, it induced only short-term immunity.

But the health passport was not without its critics. Not only did the British delegation not sign the agreement reached at the Dresden conference, but the whole idea of a health passport was rejected. The prestigious British medical journal The Lancet determined that these health passports were "useless" because they could be falsified and ineffective, as they required a human infrastructure that was disproportionate to their health performance.

Le Petit Journal front page from December 1912 — Photo: Bibliothèque nationale de France

"We can be certain that no such document will ever be required of people arriving in this country or in some of the most advanced countries on the continent," the journal concluded.

How to explain this rejection? Proust criticized the British "liberal" approach which — although restrictive on its own soil — was opposed to any measure likely to compromise international trade. For the chief physician of the Hôtel-Dieu, the British system was not to be copied. If the "bill of health," the equivalent of the "health patent," commonly used by sailors since at least the 17th century, was easier to administer, it was less effective from a health point of view.

Moreover, the laissez-faire approach to sanitation in the English colonies was detrimental. In 1896, it had led to the spread of the plague to India, where thousands of people died. The same can be said of the appearance of cholera in Egypt in 1883, 1805 and 1902, where the British colonial authorities had not put in place adequate sanitary measures.

Despite British reluctance, and with the advent of aviation from the 1930s onwards, the World Health Organization introduced an "international certificate of vaccination or prophylaxis." Now more commonly known as the "Yellow Card," it became compulsory, especially for travel to certain African countries where "endemic" diseases (such as yellow fever or malaria) are a danger not for the natives, who are forced to "live with" these scourges, but for travelers.

There's a big difference, nevertheless, between the yellow card and the so-called "COVID passport." The latter would grant immunity and freedom of movement in places considered "healthy," while the yellow card gave foreigners the right to travel in countries recognized as "unhealthy" — without, of course, bringing their "plagues" back to the metropolises of rich, developed and sterilized countries.


*Joëlle M. Abi-Rached is a physician by training, medical historian and associate researcher at the Medialab of Sciences Po, Paris. His latest book is Asfuriyyeh: A History of Madness, Modernity, and War in the Middle East (MIT Press, 2020).


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