OTTAWA -- A few weeks into what the federal government has billed as the ramp-up phase of Canada’s mass vaccination effort, the rollout is still being plagued by delays in Moderna shipments and lingering uncertainty about when and how many doses of AstraZeneca and Johnson & Johnson’s shots will land.

While somewhat buoyed by a rising global ranking when it comes to Canada’s vaccination rates— due in part to the prioritization on giving first shots to more people and delaying their second—still just over nine million doses have been administered in Canada.

Meanwhile, the third wave is raging and leading to ICUs filling up and daily new case counts at levels not yet seen during this pandemic in some communities.

“For the millions of Canadians who hear and see extensive coverage every day about the pandemic and where we are in the race between COVID-19 vaccinations and COVID-19 variants, this is a challenging time,” said Deputy Chief Public Health Officer Dr. Howard Njoo on Thursday.

After shortages in the winter due to an expansion at Pfizer’s European manufacturing facility, Canada has consistently been receiving the promised shipments of the Pfizer-BioNTech vaccine, with more than one million doses a week through to the end of May already scheduled. Starting in June, Pfizer has committed to sending closer to two million doses a week.

And, while Moderna met its first quarter commitment of two million doses and moved its shipment intervals up from every three weeks to every two weeks after increasing its capacity, a “quality assurance processes backlog” has meant the latest shipments to Canada have been inconsistent. The last Moderna shipment to arrive on time and in full, was on March 11.

A shipment of 855,000 Moderna doses scheduled to land between April 5 and 11 arrived in Canada earlier this week, with distribution to provinces and territories set to wrap up by the end of the day, Thursday. The next delivery of more than 1.2 million doses was set to land between April 19 and 25, but Maj.-Gen. Dany Fortin said Thursday that the government is planning to receive this delivery by the end of the month, potentially pushing distribution to the provinces into early May.

While Canada has confirmed shipment dates and sizes from Pfizer through to May 30, Moderna has just recently confirmed that in May, Canada will receive 2.8 million doses over two shipments, one mid-month and the second at the end of May, without specifics on the delivery dates or individual sizes of those shipments.

He recognized that the moving delivery dates have led to problems for provincial immunization plans, seeing some regions struggling to maintain clinic capacities and accelerate the number of shots they can get into arms each day and prompting frustrations from premiers.

“We're working closely with provinces and territories to risk manage this efficiently,” Fortin said. “They're lining up all the resources and we're ensuring that we were in close contact here so that they can plan better.”

Canada has authorized two other COVID-19 vaccines for use: AstraZeneca and Johnson & Johnson.

So far, deliveries have only started to trickle in of the AstraZeneca vaccine from smaller deals Canada made to get doses from COVAX, India, and the United States, rather than from the main contract with AstraZeneca-Oxford. Fortin said through these streams a total of 2.3 million doses have arrived to date with millions more doses outstanding.

Asked why Canada has yet to receive a delivery schedule let alone any shipments of the bulk of the AstraZeneca doses the federal government has contracted, Public Services and Procurement Canada director general Joelle Paquette told reporters that the pharmaceutical company is committing to one million doses coming sometime in June.

“The exact date of that distribution is unknown at this time, but we continue to work with the company to solidify that calendar,” said Paquette.

Procurement Minister Anita Anand has said that Johnson & Johnson deliveries are expected to begin arriving in Canada by the end of April.

“We have thus far been told that the deliveries will begin in the last week of April. We've also been told that the company is still ramping up production, and that the company will provide the additional precise numbers for the months of May and June in due course. And as soon as I have those numbers, I will provide them to you, which I expect to be this month,” Anand said Thursday.

The government continues to face scrutiny over the state of the rollout from the opposition parties, with NDP Leader Jagmeet Singh stating the plan is not working and needs to change.

Pointing to the example of one Scarborough vaccination site that cancelled 10,000 appointments this week, Singh said there’s still not enough doses coming in to Canada.

“The Liberal government has failed to secure enough doses. People are frustrated. Canadians are angry, and they want to know how the prime minister let things get so bad,” he said during question period on Wednesday.

Also raising the situation directly with Prime Minister Justin Trudeau on Wednesday when he was taking all of the questions, Conservative Health critic Michelle Rempel Garner said that had Canada’s January and February rollout been more robust, Canada may not be facing such a serious third wave.

“Does the prime minister really think that this is going to cut it, and that Canadians will keep allowing him to pass the buck while people get infected with variants and ICUs fill up?”

Trudeau has said that based on the overall quarterly agreements from Canada’s approved vaccine manufacturers, by June the government is expecting to have received more than 44 million doses, enough that every eligible person should be able to receive their first shot by Canada Day.