Paris (AFP)

More than a fifth of the world's population may not have access to a Covid-19 vaccine until at least 2022, with half of potential doses for next year having been reserved by wealthier countries, researchers warn Wednesday.

"The operational challenge represented by a global vaccination program against Covid-19 will be at least as difficult to meet as the scientific challenge of their development", estimates an editorial in the medical journal BMJ, which publishes this study.

Researchers from the Johns Hopkins Bloomberg School of Public Health (located in Baltimore, USA) analyzed vaccine pre-order figures announced by countries around the world even before the first authorizations.

As of November 15, 7.48 billion doses have been reserved with 13 manufacturing laboratories, making it possible to vaccinate some 3.7 billion people (since most vaccines require two injections).

However, 51% of these doses were pre-ordered by rich countries, which represent only 14% of the population, according to the researchers.

Low- and middle-income countries, or 85% of the world's population, will have to share what is left, they add.

Consequence according to them: "At least a fifth of the world population would not have access to vaccines before 2022".

According to these researchers, the implications could go well beyond health considerations alone.

“To varying degrees, international trade or travel could continue to be disrupted until treatments or vaccines for Covid become widely available,” they write.

Many countries have joined an alliance launched by the WHO and called Covax Covid-19 Vaccine Global Access, which negotiates with laboratories for equitable access to vaccines.

But the United States or Russia are not part of this program.

According to another study published at the same time by the BMJ, projections show that 3.7 billion adults around the world wish to be vaccinated against Covid.

Some countries, such as the United Kingdom, the United States or Canada have already started to vaccinate with the most advanced vaccine, that of Pfizer / BioNTech.

In Europe, its authorization could be granted around Christmas.

© 2020 AFP