The Ontario government will allow those who received an initial dose of Oxford-AstraZeneca's COVID-19 vaccine to get a follow-up shot four weeks sooner than planned, bowing to mounting pressure from residents and experts alike.
Ontarians who received a shot of AstraZeneca will now be able to get their second dose — either of the same product or another brand's mRNA vaccine — after eight weeks, rather than the 12-week wait time the province had previously required.
"This decision is based on emerging clinical evidence about the administration of two doses of different vaccines, as supported by the National Advisory Committee on Immunization (NACI)," the province said in a statement issued on Saturday.
"Evidence from multiple studies indicates that mixing of COVID-19 vaccines [receiving an mRNA vaccine after an AstraZeneca vaccine] at dosing intervals between eight and 12 weeks is safe and demonstrates a beneficial immune response."
The province had previously shortened the interval between other vaccines, frustrating those who opted to take the AstraZeneca shot.
More than 3,400 people signed an online petition urging Ontario to fall in line with other provinces and shorten the interval to eight weeks.
And on Friday, mayors in a long-standing COVID-19 hot spot region said residents should be allowed to speed up their immunization process and bolster their protection against more infectious virus variants.
"Residents should have the choice to be fully immunized sooner so they have better protection," Brampton Mayor Patrick Brown wrote.
His community is part of Peel Region, where the highly contagious Delta variant has been spreading.
Evidence shows people with just one vaccine dose are less protected against the Delta variant than against other strains of COVID-19.
Members of the Ontario COVID-19 Science Advisory Table have said the key to controlling the variant is to get people fully vaccinated as quickly as possible.
The province said AstraZeneca recipients will be eligible to book their second shots as of Monday at 8 a.m., noting those who want a second dose of the same vaccine must revisit the place where they received the first one.
Residents who wish to switch to the Pfizer-BioNTech or Moderna vaccines as a second shot may book through the provincial portal.
The province noted, however, that some evidence suggests waiting for a longer interval between AstraZeneca doses "provides higher protection."
Ontario stopped administering first doses of AstraZeneca in May over what it said was an increased risk of a rare but serious blood clotting condition. It had given out nearly a million doses of the vaccine by that point.
Province sees 502 new cases of COVID-19
Meanwhile, Ontario is reporting 502 new COVID-19 cases on Saturday, down from 574 new infections on Friday. The province is also reporting an additional 15 deaths.
The new cases include 89 in Toronto, 71 in Peel region, 51 in Waterloo and 31 in Durham, according to Health Minister Christine Elliott.
She says the numbers come from nearly 24,100 tests completed since the last daily report.
Provincial data shows 447 people are in hospital due to COVID-19, including 422 in intensive care and 277 on ventilators.
Patios reopen across the province
This weekend marks the first weekend since Ontario moved into stage one of the province's most recent reopening plan.
Outdoor gatherings of up to 10 people and patio dining of up to four people per table are now among the permitted activities.
Non-essential stores have also been allowed to reopen at 15 per cent capacity limits.
Ontario marks 11 million vaccine milestone
The seven-day average of daily cases fell to 502, its lowest point in more than eight months.
The province says 195,032 doses of a COVID-19 vaccine were administered in the last day, for a total of 11,022,452 shots given so far.
Starting Monday, residents in seven designated delta variant hot spots who had their first dose of an mRNA COVID-19 vaccine on or before May 9 will be eligible to book an appointment to get their second shot earlier than anticipated.
Those hot spot areas are: Toronto, Peel Region, York Region, Halton Region, Waterloo Region, Wellington-Dufferin-Guelph and Porcupine.