One study, which followed 600,000 people from April through mid-July, found that people who were not vaccinated were more than 10 times more likely to be hospitalized and 11 times more likely to die than those who were fully vaccinated.
The unvaccinated were 4.5 times more likely to get infected, according to the study released Friday by the U.S. Centers for Disease Control and Prevention.
The CDC also released two other studies that show vaccine protection appearing to wane in older populations, particularly those 75 and older.
The studies also show an increase in milder COVID-19 infections among fully vaccinated people.
Dr. Rochelle Walensky, the CDC director, said during a White House COVID-19 briefing Friday that the data showed “vaccination works and will protect us from the severe complications of COVID-19.”
The release of the studies comes a day after U.S. President Joe Biden announced a new vaccine mandate requiring big companies to ensure their workers are vaccinated. The order could affect as many as 100 million Americans.
Republican officials in several states joined Republican calls to fight the new mandate in court.
Mississippi’s Governor Tate Reeves, a Republican, said Friday that Biden’s federal vaccine requirements were “clearly unconstitutional” and that Mississippi would join other states in filing a lawsuit.
Montana’s attorney general, Austin Knudsen, also promised Friday to fight the new federal vaccine mandate in court as soon as the full guidelines are released.
In other developments Friday, Denmark lifted the last of its COVID-19 restrictions. Vaccine passports are no longer required to enter nightclubs; the rule was removed for other venues Sept. 1.
On Saturday, Denmark will celebrate its new status with a sold-out concert for 50,000 people.
The Scandanavian country’s vaccine rollout has gone well, with 73% of its 5.8 million population fully vaccinated, including 96% of those 65 and older.
In France, former French Health Minister Agnes Buzyn was charged Friday over her handling of the COVID-19 pandemic, according to the Agence France-Presse.
Buzyn was charged with “endangering the lives of others.”
French officials Friday also unveiled new restrictions for U.S. travelers not vaccinated against the coronavirus. Those travelers now must show “pressing grounds for travel” in addition to the previous requirement of a negative COVID-19 test.
In South Africa, health officials began vaccinating children, taking part in clinical trials of China’s Sinovac Biotech inoculation for children 6 months to 17 years.
The Johns Hopkins Coronavirus Resource Center said late Friday that it had recorded 223.6 million global COVID-19 cases and 4.6 million deaths. The center said 5.6 billion vaccine doses have been administered.
Some information for this report came from The Associated Press, Reuters, and Agence France-Presse.