WASHINGTON – The Pentagon's initial allotment of coronavirus vaccine will be administered at 16 defense sites in the United States and abroad, with health care workers, emergency service personnel and residents of military retirement homes getting top priority, officials said Wednesday.Next in line, once follow-on supplies of vaccine becomes available, will be military personnel who provide “critical national capabilities,” such as nuclear weapons crews and cybersecurity forces, as well as certain military units getting ready to deploy.The vaccinations will be voluntary because the Pfizer vaccine initially is to be made available on an emergency use basis.