Coronavirus: Why some New Zealanders are allowed to get 'not as effective' AstraZeneca vaccine over Pfizer

AstraZeneca will soon be available as a second COVID-19 vaccine for a select group of New Zealanders.

Director-General of Health Dr Ashley Bloomfield says Pfizer will still be the primary COVID-19 vaccine in Aotearoa, but AstraZeneca will be available to people who either cannot get Pfizer for medical reasons or those who are mandated to be vaccinated but don't want a mRNA vaccine.

The AstraZeneca vaccine will be available as a second option for people aged 18 and over and it requires two doses to be effective.

"Our programme is, for good reason, a Pfizer-based programme and that was a deliberate decision. It's turned out to be one of the most effective and safest vaccines, including against Delta," Dr Bloomfield says. 

"AstraZeneca is there as an option for people who can't have the Pfizer or people who are required to be vaccinated because they're captured under an order [and they're] not willing to have a mRNA vaccine, and this gives them an alternative vaccine."

But he admits while AstraZeneca is an advantageous vaccine to get, it is "not as effective" against Delta as Pfizer is.

"All vaccines have advantages and disadvantages, benefits and risks. We know that the effectiveness and safety profile of the Pfizer vaccine is very good. AstraZeneca is not as effective against the Delta variant, we know that as well, and it has some specific rare side effects that have been well-publicised," he says. 

A rare side effect includes a blood clotting problem linked to low levels of platelets that has affected a small number of people. 

Dr Ashley Bloomfield.
Dr Ashley Bloomfield. Photo credit: Getty Images

"We want to make sure that anyone deciding to have the AstraZeneca vaccine has access to that information just as we have provided it for access to the Pfizer vaccine," Dr Bloomfield says.

He adds that more detail will be provided next week.

The Government has made an advance purchase agreement of 7.6 million doses of AstraZeneca. Since this is a two-dose vaccine, it is enough for 3.8 million people.

Aside from Pfizer and AstraZeneca, New Zealand has purchase agreements with two other COVID-19 vaccine companies: Janssen Pharmaceutica and Novavax.

Medsafe has granted provisional approval of the Janssen vaccine, but not yet for Novavax.