A nurse administers the Moderna vaccine to a health care worker at the Putnam Clubhouse at Gillette Stadium in Foxboro, Massachusetts. Credit: Mark Stockwell / The Sun Chronicle via AP

BOSTON — All Massachusetts residents age 75 and older are now eligible to make an appointment to get a COVID-19 vaccine, but Wednesday’s online rollout did not go smoothly for some.

Residents could start scheduling an appointment starting at midnight for shots being administered starting Monday at one of more than 80 sites around the state, from mass vaccination sites like Gillette Stadium to local pharmacies and supermarkets.

Monica Nelson, a retired nurse from Newburyport, told The Boston Globe in an email that she spent two hours trying to get her 75-year-old husband a slot with no luck. She called the rollout a “disaster.”

Syracuse University student Ghael Fobes, on the other hand, logged on just after midnight and was able to make appointments for his grandparents.

State health officials urged patience, warning that it may take several weeks to get an appointment and that as more vaccine supply arrives, additional appointments will become available.

Once vaccinations are completed for residents 75 and older, those who are older than 65 and those with two chronic illnesses or medical conditions will be eligible.