US President Joe Biden's administration Friday announced new personnel such as dentists, veterinarians, and health care students will be recruited to the nationwide COVID-19 vaccination effort.

The move came as the country was poised to soon administer the 100 millionth shot since its inoculation campaign began on December 14.

Biden wants every adult to be eligible for a vaccine by May 1, with the goal of beginning to return to normal by July 4, the United States' independence day.

"The Department of Health and Human Services will launch a new portal to help individuals determine where they can sign up to volunteer to administer shots," Marcella Nunez-Smith, who leads the administration's health equity task force, told reporters.

The administration previously authorized any physician or most classes of nurse either active or retired in the past five years to administer the shots.

With the new action, more classes of vaccinators have been authorized including dentists, emergency medical technicians (EMTs), midwives, optometrists, paramedics, physician assistants, podiatrists, respiratory therapists and veterinarians.

Students in those categories are also authorized.

The United States is currently vaccinating around 2.2 million shots per day, while almost 65 percent of Americans 65 and older have gotten at least their first shot.

The state of Michigan said Friday it wanted to drop eligibility requirements for vaccines by April 5, effectively ushering in "open season" for all adults.

Alaska became the first state to eliminate priority groups on Tuesday.

The Pfizer, Moderna and Johnson & Johnson vaccines have all been authorized for emergency use, and the companies are set to deliver more than enough to cover the entire US population by mid-year.

AstraZeneca and Novavax are also carrying out late stage clinical trials for their vaccines that could also be authorized if they perform comparably to those already being distributed, and are still required.