Vatican authorities said Monday that Pope Francis has a complex infection in his respiratory system and will require more targeted drug treatment.

It now hopes to hit a more positive milestone by becoming one of the first countries in the world to start vaccinating its population against COVID-19. The U.K. government has agreed to buy more than 350 million doses of vaccines from seven different producers, should they prove effective, as it prepares to vaccinate as many of the country’s 67 million people as possible. The Moderna vaccine is expected to be referred soon to the U.K.'s Medicines and Healthcare Products Regulatory Agency, to see if it is safe and effective. Britain has ordered 40 million doses of the Pfizer/BioNTech vaccine and 100 million doses of the Oxford/AstraZeneca vaccine. The Moderna vaccine, which also needs to be stored at freezer temperatures, was also about 95% effective in clinical trials, the company said.

U.K. researchers said Tuesday Oct. 20, 2020, they are preparing to begin a controversial experiment that will infect healthy volunteers with the new coronavirus to study the disease in hopes of speeding up development of a vaccine. This type of research, known as a human challenge study, is used infrequently because some question the ethics of infecting otherwise healthy individuals. Alastair Fraser-Urquhart, 18, of Stoke-on-Trent in northwestern England, said he wants to take part in the challenge study because he’s young and strong and can help move the vaccine research forward quickly. Challenge studies are typically used to test vaccines against mild infections to avoid exposing volunteers to a serious illness if the vaccine doesn’t work. Those steps include examining the ethics of a challenge study, and funding research to create lab-grown virus strains that potentially could be used.