Nearly 40% of US Marines are declining Covid-19 vaccinations, according to data provided to CNN on Friday by the service, the first branch to disclose service-wide numbers on acceptance and declination. As of Thursday, approximately 75,500 Marines have received vaccines, including fully vaccinated and partially vaccinated service men and women. About 48,000 Marines have chosen not to receive vaccines, for a declination rate of 38.9%. The declination rate at Camp Lejeune in North Carolina, one of the prominent Marine Corps bases, was far higher, at 57%, according to another set of data. Of 26,400 Marines who have been offered vaccinations, 15,100 have chosen not to receive them. The military cannot make the vaccines mandatory now because they have only emergency use authorizations from the Food and Drug Administration, meaning service members who are required to receive a series of other vaccinations have the option of declining shots to protect against Covid-19. Officials say most of the vaccine hesitancy stems from concerns about the speed at which the vaccines were developed and fears over long-term effects. The Defense Department has approximately 2.2 million service members operating around the globe.