In France masks are no longer needed to be worn in enclosed spaces, except in healthcare centres, senior living homes (for visitors and workers) and pharmacies. As far as the 4th Global Congress on Sickle Cell Disease is concerned, the use of a mask will be left to the choice of each attendee.
In France, pharmacies are doing antigenic rapid tests.
Attendees might need a PCR test to travel back to their home countries. In France, PCR tests are done in laboratories. Attendees will have to schedule and book their tests in advance. Here is a link to the locations in the 15th (where the Novotel Paris Tour Eiffel is located) to do PCR tests.