The United States had administered 401,819,240 doses of Covid-19 vaccines in the country as of the morning of Oct. 9 and distributed 487,277,035 doses, the U.S. Centers for Disease Control and Prevention said.

A World Health Organization spokesperson said on Oct. 8 that the health agency was “near” to resolving issues on Russia’s Sputnik V Covid-19 vaccine, without giving a date for a potential emergency use listing.

Immunology is one of the more complicated areas of the life sciences, and recent studies on the long-term efficacy of the mRNA vaccines against Covid-19 are prime examples of just how complicated it can be.

Pfizer Inc. and BioNTech SE asked U.S. regulators to authorize emergency use of their Covid-19 vaccine for children ages 5 to 11, a group for whom no shot is allowed, Pfizer said on Oct. 7.

Moderna is seeking to invalidate two patents belonging to Arbutus Biopharma that deal with drug-delivery technology.

A new study helps quantify the improved protection against Covid-19 achieved with a third booster dose of the vaccine from Pfizer Inc. and BioNTech SE in cancer patients who are undergoing chemotherapy.

Johnson & Johnson submitted data to the U.S. Food and Drug Administration for emergency use authorization of a booster shot of the company’s Covid-19 vaccine in people aged 18 and older.

The effectiveness of the Pfizer Inc./BioNTech SE vaccine in preventing infection by the coronavirus dropped to 47 percent from 88 percent six months after the second dose, according to data published on Oct. 4 that U.S. health agencies considered when deciding on the need for booster shots.

Johnson & Johnson is expected to ask the U.S. Food and Drug Administration to authorize a booster for the company’s one-shot Covid-19 vaccine this week. In other news, President Biden’s chief medical advisor Dr. Anthony Fauci told CNBC that they expect the FDA to review data on Merck and Ridgeback Biotherapeutics’ new oral antiviral against Covid-19 “as quickly as they possibly can.”

The European Union’s drug regulator on Oct. 1 identified a possible link between rare cases of blood clotting in deep veins with Johnson & Johnson’s Covid-19 vaccine and recommended the condition be listed as a side effect of the shot.