Coronavirus: Gap between Pfizer COVID-19 vaccine doses extended to six weeks

The gap between COVID-19 vaccine doses will be extended from three weeks to six, the Government announced on Thursday, hoping to get first jabs into more Kiwis' arms so they have some protection should an outbreak occur.

"This is an important part of our being prepared for a possible outbreak of the more infectious Delta variant of the virus," Director-General of Health Ashley Bloomfield said on Thursday. 

"Early findings from a small number of well-designed studies show that an extended duration between doses of the Pfizer vaccine gives at least an equally robust immune response, with no additional safety concerns."

Other countries have made similar moves, he said, and it also reduces the likelihood of rare side effects like myocarditis or pericarditis (both forms of heart inflammation). 

"I do want to reassure people that if you have already been fully vaccinated with two doses less than six weeks apart, as we have been doing, you will have very strong protection against the virus and do not need to doubt that," said Dr Bloomfield.

"People who already have vaccinations booked less than six weeks apart can keep their second appointment or choose to change it. Either way, the most important thing is that everybody needs two doses of the vaccine to be fully vaccinated."

Some people, such as the immunocompromised or border workforce, would still be encouraged to get their doses closer together so they're protected sooner, being more at risk. People heading overseas too will be advised to get both doses first, even if that means they're closer than six weeks apart.

The vaccine takes a while to kick in, so it's not at its strongest until about two weeks after the second jab. Some studies have shown the longer you wait, the stronger the immune response - up to about 12 weeks. The UK used this strategy during its outbreak earlier this year, trying to give as many people at least some protection as possible. 

"This change won’t impact when we finish our vaccination campaign, but it will ensure more New Zealanders are at least partially vaccinated quicker so our whole population is better protected against any future outbreak," said Dr Bloomfield. 

The new six-week gap will be offered to anybody booking through the website from Thursday. Those who received their jab at the first Manukau mass vaccination event have already been booked in to receive theirs six weeks later.

From Friday, people aged as young as 50 will be able to book, and the 40-49 group will join them on August 18, followed by people in their 30s from August 25. From September 1, everyone eligible will be able to book jabs. 

"We are progressing well with our roll-out plan and are on track to make the vaccine available to everyone in New Zealand aged over 16 by the end of the year," said Dr Bloomfield.