Astrazeneca vaccine bookings set to begin

People born in 1957 first up for shots — 1972 for Indigenous residents

Older adults — and more Indigenous people in Alberta without a chronic illness — will be able to sign up for the Astrazeneca COVID -19 vaccine starting Wednesday.

Vaccination appointments will open by birth year, one year at a time, for adults aged 50 to 64, as well as First Nations, Métis and Inuit people aged 35 to 49 for the first 58,500 doses.

Booking on March 10 starts with anyone born in 1957, or 1972 for Indigenous peoples. Other birth years will be announced one year at a time as long as supplies last.

Appointments can be booked on Alberta Health Services' website or by calling 811.

WHO SHOULD TAKE THE ASTRAZENECA VACCINE?

Only certain people are recommended to get an Astrazeneca vaccine — but peer-reviewed scientific research, and health authorities in Canada and other parts of the world, say it is safe and works.

In general, this particular vaccine is recommended only for people 18 to 64 years old because more research on its safety and effectiveness outside this age range is still being done.

“In line with the National Advisory Committee on Immunization's recent recommendation, and what other jurisdictions are doing, we will only be administering the Astrazeneca vaccine to healthy adults aged 64 and under at this time,” Alberta Health spokeswoman Sherene Khaw said in an email Monday.

It's also recommended only for people who are healthy and unlikely to become very sick from COVID -19.

Health-care workers, those who live, work with, or care for people who are at a high risk or in “congregate settings” should not get this vaccine, Alberta Health says.

People who are pregnant, have an autoimmune disorder, or who are immunocompromised should ask their doctors before signing up.

HOW EFFECTIVE IS IT COMPARED TO THE PFIZER AND MODERNA VACCINES?

Research shows this vaccine works but is less effective than the Pfizer and Moderna vaccines.

Alberta Health says Astrazeneca reduces the rate of COVID-19 infections by between 60 to 70 per cent and reduces hospitalizations by 80 per cent.

Clinical trials showed Astrazeneca was about 62 per cent effective in preventing infections with two doses, compared to about 94 per cent for Pfizer and Moderna.

IS ONE DOSE ENOUGH?

Starting March 10, people who sign up for the Astrazeneca, Pfizer and Moderna vaccines in Alberta will not get their second appointment for about four months, following recommendations from the National Advisory Committee on Immunization (NACI).

It's not fully known how the effectiveness with the delay will be affected but all three vaccines have been shown to protect people from COVID -19 after just one dose.

The NACI estimates one dose of Astrazeneca vaccine is about 64 per cent effective 22 days after the first dose. A single shot of both the Pfizer and Moderna vaccines were about 92 per cent after 14 days, according to a review by the NACI, although it warned to interpret this estimate with caution because of study limitations.

But the Astrazeneca vaccine might become more effective by spreading doses out a little longer.

A recent U.K. study published in the Lancet found it was 81 per cent effective with two standard doses when the second was given three months after the first dose, compared to just 55 per cent effective with shots six weeks apart.

In this study, one dose was 76 per cent effective for symptomatic cases of COVID-19 in the first three months, but there wasn't any protection for asymptomatic cases.

ASTRAZENECA USES A HARMLESS VIRUS

Another difference between this vaccine and those from Pfizer and Moderna is the delivery mechanism.

The vaccine developed by Astrazeneca and Oxford University uses a harmless virus, called a vector virus, to teach the body how to respond if it comes into contact with the virus causing COVID-19.

It's an adenovirus, similar to that which causes the common cold, that produces the spike protein in SARS -COV-2. It doesn't infect the person with COVID -19 and uses a method similar to other safe vaccines.

The other two are MRNA vaccines, which use messenger RNA that give cells instructions for how to make the same spike protein.

WHERE CAN I BOOK?

Appointments can be booked online through Alberta Health Services, by calling 811, or by looking for a participating pharmacy by looking on the Blue Cross website.

AHS scheduled upgrades to its online vaccine booking tool overnight Monday to 2 a.m. Tuesday.

People with mobility issues and seniors can call 211 to find rides to appointments.