OTTAWA -- More than half of all eligible adults in Ottawa have now had at least one dose of a COVID-19 vaccine.

In a tweet, Ottawa mayor Jim Watson said the city surpassed the milestone Saturday night.

"Yesterday evening we surpassed a significant milestone in our #CommunityImmunity vaccination campaign," Watson tweeted. "50% of the population aged 18 or older have received their 1st dose of vaccine."

In a short video attached to the tweet, councillor Keith Egli, chair of Ottawa's board of health, said 425,000 residents have so far received at least one dose of a vaccine.

"That's 50 per cent of the eligible population 18 or older in the nation's capital who have received at least one dose," said Anthony Di Monte, general manager of emergency and protective services and the head of Ottawa's local vaccination rollout.

Ottawa Public Health's COVID-19 vaccination dashboard updates every Monday, Wednesday and Friday; however, in an email to CTV News Ottawa on Sunday morning, OPH said 431,676 Ottawa residents had received at least one dose of a COVID-19 vaccine as of 11 p.m. Saturday.

In an interview with CTV News Ottawa on Sunday, Watson said there's still work to do with the vaccination campaign.

"Notwithstanding, we're still not out of the goods. It's some glimmer of good news and hope for the future."

Watson is optimistic Ottawa will reach the 75 per cent mark of residents vaccinated "very shortly."

"We can't let up. We have to remind people we're still in a pandemic, and we have to push even harder to get to that next 75 per cent threshold, which will give us those freedoms we've been yearning for for the last year and a half," said Watson.

At a community vaccination clinic on Sunday, residents receiving the vaccine said it was a relief to get the dose.

"I feel free. It's one step towards freedom and the more people that are vaccinated, the safer everyone will be," said one person shortly after receiving the vaccine.

"I feel relief. It's finally done, I feel good," said another resident."

There are an estimated 850,000 adults 18 and older in Ottawa, based on an estimated city-wide population of 1,055,000.

All but one of the vaccines that have been approved for use in Canada require two doses to be fully effective. Canada's vaccination strategy has focused on extending the interval between first and second doses by up to 16 weeks for most people in order to give first doses to as many Canadians as possible, as evidence shows a single dose still provides significant protection against severe illness from COVID-19.

The Johnson & Johnson vaccine requires only one dose to be fully effective, but use of the vaccine is on hold as Health Canada reviews a possible quality control issue involving the 300,000 doses of the vaccine that arrived in late April. 

Vaccinations through the Ontario booking system opened to residents 40 and older last Thursday and had previously expanded to people with certain health conditions and frontline workers last Tuesday. This coming week, the Ontario portal will begin accepting bookings from anyone 30 and older, though a specific date has yet to be announced. The province says it aims to open the booking system to anyone 18 and older the week of May 24.

Local figures for vaccinations have been on the decline in recent weeks, though data suggest that's mainly due to fewer AstraZeneca doses being administered. The AstraZeneca vaccine was largely in the hands of pharmacies and primary care clinics, while the city's inventory consisted mostly of the Pfizer-BioNTech and Moderna vaccines.

According to OPH data, administration of the AstraZeneca and Moderna vaccines has been dropping steadily since the week of April 18, but the number of residents receiving the Pfizer vaccine has been rising. OPH says 60,184 vaccine doses were administered the week of April 18 compared to 48,983 the week of May 2.

April 18

  • Pfizer: 21,851
  • Moderna: 17,893
  • AstraZeneca: 20,440

May 2

  • Pfizer: 35,396
  • Moderna: 6,296
  • AstraZeneca: 7,291

On Tuesday, Ontario announced it would no longer use the AstraZeneca vaccine for first doses following a reported rise in the rate of rare and dangerous blood clots. The decision was strongly criticized by one of the researchers who oversaw development of the vaccine in an interview with CTV's Question Period.

Many health officials stressed that those who were vaccinated with the AstraZeneca vaccine did the right thing by protecting themselves and others. The province has yet to announce a plan for second doses for the roughly 900,000 people who received their first shot of the AstraZeneca vaccine. More than 250,000 doses of the vaccine are set to arrive in the province in the coming days.

According to the latest available OPH data, 66,996 residents of Ottawa had received at least one dose of the AstraZeneca vaccine, and only 44 had both.

In the short video that Watson shared on Sunday morning, Ottawa's medical officer of health, Dr. Vera Etches, encouraged everyone to sign up for a vaccine as soon as they are able.

"Please make an appointment to get a vaccination," Etches said. "We can beat this together and we're almost there."