Quynh Tran, a clinical pharmacist from The Public Health Commission Corps, prepares a vial of Moderna vaccine on Tuesday, April 13, 2021, at a mobile vaccination unit that was stationed at the Oxford Casino in Oxford, Maine. Credit: Andree Kehn / Sun Journal via AP

More than 6,000 Mainers received COVID-19 booster shots in the first few days after the federal government on Thursday authorized additional doses for older and immunocompromised people and anyone who received the Johnson & Johnson vaccine.

Over 74,800 Mainers had received booster shots on Sunday, according to data from the Maine Center for Disease Control and Prevention, up from 68,000 on Thursday. The rise follows a Thursday decision from the U.S. Centers for Disease Control and Prevention to expand booster eligibility and allow people to “mix and match” vaccine doses, or receive a booster different from the vaccine course they initially received.

Federal regulators previously authorized third doses for severely immunocompromised people as well as boosters for individuals at increased COVID-19 risk who had finished the two-dose Pfizer vaccine course at least six months prior. Last week’s approvals expanded eligibility significantly, as about 45 percent of Mainers 65 and older have received the Moderna vaccine while a bit shy of 9 percent of the state’s population received the Johnson & Johnson shot.

Access to boosters was still uneven across the state in the early going, with only some locations offering the additional shots immediately and most requiring appointments.

The Mainers who have received additional doses so far account for about 5.5 percent of the state’s population, making Maine one of nine states where at least 5 percent of its population has received boosters, according to U.S. CDC data. Vermont leads all U.S. states with 7.1 percent of its population having received a booster shot.

Overall, just over 1 million Mainers, or about 76 percent of the state’s total population have received at least one COVID-19 dose, according to federal data, while 70 percent are fully vaccinated, meaning they have received at least two doses of the Moderna or Pfizer vaccine or the single shot Johnson & Johnson vaccine.