Paris (AFP)

Covidtracker, Vaccintracker, Vitemadose and now Chronodose: Guillaume Rozier has created, alone and then with other volunteers, free anti-Covid internet services.

Faced with their great public success, the young man says himself surprised by "the creativity that emanates from data".

From Wednesday, Chronodose, the youngest in the series, will make it possible to search for a vaccination appointment that remained available the same day or the next day.

It will thus allow all adults to easily benefit from the government's decision to open to all over 18, regardless of age or health, the vaccination slots not taken the following day.

"Every day there are still a few thousand vaccination slots not provided for the same day and the next day," Guillaume Rozier, 25, told AFP.

Chronodose will be an additional feature of Vitemadose.

Launched in early April, this website provides a single glance at the time slots available on the various appointment platforms, Doctolib, Keldoc, Maiia, Ordoclic or MaPharma.

Vitemadose - greeted by Emmanuel Macron himself - was created by Guillaume Rozier with the help of a hundred volunteers, after the public success of Covidtracker, the site for monitoring the evolution of the pandemic that made it known .

At the beginning of March 2020, Guillaume Rozier is finishing his engineering studies at Telecom Nancy, with a specialty in artificial intelligence and big data processing.

Faced with the deterioration of the health situation in Italy, he wonders: is France following the same path?

He will look for statistics on mortality and the number of cases collected by the American University Johns Hopkins and draws a graph comparing the evolution of the two curves.

The answer is clear, France is indeed following, with a few weeks delay, the Italian evolution.

He shares his graphic with his relatives, who are interested in it, and demand a daily update.

It automates the creation of the table on a web page and broadcasts the link on Twitter ...

- Champion Audience -

Shared by Internet users, constantly improved, the site soon to be called Covidtracker is establishing itself as a reference for information on the progression of the pandemic in France.

It achieved audience scores that would make many champions of the attention economy pale: "10 million distinct users in April 2021", according to Guillaume Rozier.

The site is used by journalists, cited by the authorities ... In January, he created Vaccintracker, which monitors the progress of vaccinations.

Fueled at the beginning by simple cross-checks of information published by the press, in particular by the regional press, the site ends up receiving unofficially information from the Ministry of Health, transmitted by Olivier Véran's office.

Worried about a risk of instrumentalisation, Guillaume Rozier comes to threaten the ministry to cease publication, if the data is not made in free access ... which is done a little later.

For the calm young man, the enormous success of Covidtracker and Vitemadose is the "tangible demonstration", including for the general public, of the importance of the release of data held by the State and the administrations (open data).

"Every piece of data that is produced by an administration should be published quickly, comprehensively, and in a format accessible by a machine," he emphasizes.

Even if the administration does not know how this information will be used, even if no project is foreseeable, there may be somewhere a developer who will start pulling a thread, to create something new, explains- he does.

"I would never have imagined the innovations, the creativity that emanated from the data" on the pandemic, from a very simple and very modest start in early March 2020, he recalls.

"One can imagine all that this access to data can bring out, in health more generally, but the whole economy, transport, global warming, energy ...", adds the young man, who now works for a French IT consulting group, a subsidiary of the American group Accenture.

© 2021 AFP