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Paolo Rossi Castelli25 Mar 20214 min read

Is it possible to vaccinate 80 million people in 3 months? Yes, it is

Not many people remember what happened in Brazil, in 1975, when a massive immunisation campaign against meningitis was carried out in record time thanks to an unparalleled mobilisation effort.


Vaccinating 80 million people in just three months, i.e. administering the vaccine to the entire population of Italy, Switzerland and Austria in such a short space of time.

In the height of COVID times, despite the efforts of the authorities, this seems to be impossible. And yet, 46 years ago, such a feat was successfully completed on the other side of the ocean, in Brazil, against meningococcal meningitis, in the space of just a few weeks, resulting in the eradication of the disease (an infection of the meninges, i.e. the membranes that surround the brain and the spinal cord). However, not many people remember this extraordinary event.

Perhaps it is worth looking back at this story, to which an interesting article was dedicated in the French newspaper Le Monde, and which was also translated and reported in the Italian journal Internazionale.

Meningococcal meningitis (a bacterium) is a dangerous disease, which was widespread in the 1970s, especially in a large area of Africa, spanning from Senegal to Ethiopia (the so-called meningitis belt), with epidemic waves that killed thousands of children every year, but which also hit other countries hard from time to time, like it did back then in Brazil. The epidemic appeared there at the beginning of the 1970s, but by 1975 it had reached extremely high peaks, with dozens of children dying every day. And just like what is currently happening with COVID, a variant of meningitis (called African type A) appeared, which was much more aggressive than the “classic” strain and rapidly became dominant, with no possibility of effective treatment.

An extraordinary request

Therefore, the courageous and desperate decision was taken to carry out mass vaccination of the Brazilian population as quickly as possible to prevent infection.

As reported in Le Monde, the pharmaceutical giant Merck developed a vaccine against the C strain of meningococcus, but production was slow and suffered long delays. Another vaccine, against the A strain (the most widespread in Brazil, including its variant), was also developed by a small French company, the Institut Mérieux (currently partly owned by Sanofi Pasteur). The news of the successful results of the latter vaccine, approved by the World Health Organisation, gave new hope to Brazil’s health minister, General Paulo de Almeida Machado (at that time Brazil was ruled by a military dictatorship).

Machado contacted the Institut Mérieux and made an “extraordinary” request: to manufacture 50 million doses in a very short period. “‘The company had never manufactured more than several hundred thousand doses,’ writes Nathaniel Herzberg, author of the Le Monde article, “but two million were needed within one month for the first experimental campaigns alone”. And then, of course, tens of millions more.

What seemed impossible – and still seems unattainable during COVID times – was achieved, thanks to an extraordinary effort and the sound ethics of the managers of Mérieux. Production was quickly reorganised, some manufacturing activities were outsourced to external laboratories, and the “machines” needed to make the vaccines were upgraded. In the space of just a few weeks, the first supplies of bivalent vaccines (i.e. vaccines effective against both the A and C strains) were delivered, having been transported by aeroplane from France to Brazil, respecting a strict cold chain (the vaccines had to remain at -20 degrees centigrade, as still is the case today with several types of anti-COVID vaccines).

The first city to receive abundant supplies of the vaccine was Rio de Janeiro, where 4 million inhabitants, out of a total of 4.8, received one injection over the course of twelve days, in time for Carnival, which no one would have been able to cancel (and which, without the vaccine, would have had a very serious effect on the multiplier of the infection). The next city was São Paulo, with its ten million inhabitants. To speed things up, hundreds of vaccination centres were set up at every possible location, including schools, churches, railway stations, bus stops and road crossings. The unmistakable sign of the presence of the vaccination points was large balloons floating several metres up, so that they could be seen from miles around.

“In the meantime,” Herzberg writes, “loudspeakers were broadcasting the anthem written for the occasion, a samba de vacinaçao”. It took five days to vaccinate São Paulo (a record that has never been beaten), and then it was the turn of the rest of Brazil. In the end, 80 million people were vaccinated (therefore more than the 50 million initially forecast), out of a total of 110 million, in less than three months. The epidemic disappeared, and never came back.

Why can all this not be replicated today, with COVID?

The situation was very different, of course, as were regulations and safety standards. “However, it is also true that Mérieux took an enormous industrial risk, driven by concern for public health,” says Baptiste Baylac-Paouly, an historian of science, “This could not happen today”.


Paolo Rossi Castelli

Journalist since 1983, Paolo has been dealing with scientific divulgation for years, especially in the fields of medicine and biology. He is the creator of Sportello Cancro, the site created by on oncology in collaboration with the Umberto Veronesi Foundation. He collaborated with the pages of the Science of Corriere della Sera for several years. He is the founder and director of PRC-Comunicare la scienza.

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