Interval between AstraZeneca vaccine doses to be reduced

Plan to reduce timespan in stages from 12 weeks to eight contingent on supplies

The interval between doses of the AstraZeneca vaccine against Covid-19 is to be reduced on a phased basis, Minister for Health Stephen Donnelly has announced.

However, the plan to reduce the interval in stages from 12 weeks to eight is contingent on supplies.

Taoiseach Micheál Martin, Mr Donnelly and the high-level vaccine Taskforce have all been in contact with AstraZeneca to stress the urgency of supplies arriving in Ireland "as agreed," the Minister said on Friday.

“The reduction in the length of the interval between doses of this vaccine will benefit in excess of 400,000 people who are waiting on a second dose and who will now get the protection of being fully vaccinated earlier,” according to Mr Donnelly.


Under the phased approach being adopted, those who are due a second dose of AstraZeneca over the coming fortnight under the existing 12-week schedule will receive it as planned.

“We will then implement a graduated reduction so the interval will reduce to 11, 10, nine and then eight weeks.”

Further detail of the planning for the new approach will be worked out by the HSE over the weekend.

The exact timing remains contingent on supplies from AstraZeneca, Mr Donnelly said.

“Right now we only have confirmed volumes for the next two weeks. I’ve spoken with the company, while there has also been contact with them from the Taoiseach and the taskforce in recent days to emphasise the urgency and importance of contracted supplies arriving as agreed.”

The Minister's announcement follows a recommendation by the National Immunisation Advisory Committee that people of any age who have received a first dose of the vaccine should receive the second dose eight to 12 weeks later.

Almost half a million people still have to get a second dose of the vaccine between now and mid-August under current plans. Over 32,000 people are expected to receive a second AstraZeneca dose this week, rising to a peak of 124,000 in the third week of July before tapering off the following month.

Niac has also recommended that those aged under 50 who are “immunocompetent” and who had Covid-19 in the nine months before their first dose of AstraZeneca do not require a second dose. They are now considered fully protected 15 days after their first dose.

Total vaccinations are likely to pass the three million mark on Friday; at least 53 per cent of adults have received a first dose and 25 per cent are fully vaccinated against the virus.

Over 2.9 million vaccines doses had been administered up to Wednesday. More than 2 million people, or 53 per cent of adults, have received a first dose, while 900,000 have received a second dose, or 25 per cent of adults.

Paul Cullen

Paul Cullen

Paul Cullen is Health Editor of The Irish Times