MONTREAL -- Quebec has dropped the age limit for the AstraZeneca vaccine to give access to people 45 and up, it announced Tuesday.

The change took effect Wednesday morning, Premier François Legault said in a press conference. Quebecers can book appointments on the province's website.

"If you're 45 years old, hurry up," said Legault on Tuesday. "Go make your appointment."

"I'm repeating myself, [but] it's very important -- we got the okay from public health, the AstraZeneca vaccine is very safe and very effective."

As of early Wednesday morning, lineups extended outside several of the province's walk-in clinics. 

"[I] feel relieved," one woman told CTV News while waiting for her number to be called at the Bob Birnie Arena in Pointe-Claire. "I'll stay here as long as it takes."

For the past few weeks, the age limit for AstraZeneca in Quebec has been 55 and up. 

Legault added that despite the recently announced cut to incoming Moderna doses, Quebec is expecting another big shipment of the Pfizer vaccine next week and that he's "counting" on people to get the vaccines they can.

"The vaccine is the way to regain our freedom, but that will only happen when a majority of Quebecers are vaccinated," he said.

Walk-ins, as well as pre-booked shots, may both be an option, said officials at the press conference. Previously, when the age limit was 55 for AstraZeneca, the province allowed people to drop in with no appointment, creating record high numbers of daily vaccinations.

Either way, to get the vaccine, Quebecers must actually be 45 years old, not born in a certain birth year, which was how the previous age-based categories worked.

WHY A HIGHER CUTOFF THAN ONTARIO?

Ontario this week lowered the age limit for the AstraZeneca vaccine to 40. When asked why Quebec went with 45, Legault said the limit could still change from region to region within Quebec, as it's based on a risk-versus-benefit decision based on the severity of the pandemic.

Essentially, experts at the province's public health institute looked at the spread of the virus and made a calculus about whether the risk of blood clots was higher, among the younger age group, or the risk of getting serious COVID-19  complications.

"The reason why that age was chosen may change from one territory to the next -- it's because of the incidence of the illness," Legault said.

Ontario would probably make a different "risk analysis," added Public Health Director Dr. Horacio Arruda.

Quebec experts weighed the potential risk of "coagulation and blood clots" versus data on hospitalizations and deaths among people in the age group at issue -- people in their 30s and 40s.

"When we look at our data... what are the age groups that are being hospitalized or that go to ICU," said Arruda, "the 45-year limit seems to be the right number for Quebec."

But "if we were in Ontario, for example, with a much greater incidence, well then, the risk of being hospitalized and of having complications is greater."

In the same vein, if Quebec's case numbers start looking worse, the AstraZeneca age limit may be lowered, Arruda said.

The blood clots are extremely rare, but more of them have been reportedly found in women. When asked about this, Arruda said there's no recommendation along gender lines for now.

"When we look at the data... [it] was not necessarily a segregation of gender," he said.

"It's true that there were some cases with younger women in some countries, but currently we don't have any recommendations as to gender," he said.

REGIONAL LOCKDOWNS, CURFEW EXTENDED

Legault said that while Quebec is not facing as dire a situation as Ontario, its statistics show a slow rise of the virus, with three regions especially hard-hit, namely Quebec City, Chaudière-Appalaches and Outaouais.

Hospitals are nearing capacity in those three regions, Legault said.

Quebec is also extending its special COVID-19 lockdown there until May 3, as well as maintaining the 8 p.m. curfew in Montreal and Laval, even though -- to the premier's astonishment, he said -- cases are still stable there.

"It's almost hard to understand how the cases and hospitalizations have stabilized in Montreal and Laval," he said.

He said he understands people's frustration over the curfew but the province believes it's still necessary.

"Of course, it's not ideal," he said, noting the ongoing protests against the curfew, the most recent of which was this Sunday.

"We all undersand that it's not fun to have to go home at 8 p.m., but... we have to be prudent in all areas of Quebec, because it can take a few days to explode, especially with the variants that are much more contagious," he said.