The Pfizer vaccine against Covid-19 should not be given as a second dose to people who originally received the AstraZeneca vaccine, the National Immunisation Advisory Committee has advised.
Niac has recommended against mixing vaccine doses at this point in time, pending further studies of the effectiveness of this approach, according to HSE officials.
Niac's advice was to stick with the two-dose schedule and not to mix vaccines, HSE chief clinical officer Dr Colm Henry said.
Separately, the HSE is assessing a proposal to reduce the interval between AstraZeneca doses from 12 weeks to eight and will make a recommendation to the Minister for Health shortly on how it plans to proceed, HSE chief executive Paul Reid told a briefing on Thursday.
It will first seek confirmation of future supplies from the company as well as examining modelling on the impact of the change on the vaccine rollout.
The executive is also assessing the implications of a change in the period of presumptive immunity from Covid-19, from six months to nine months. This will increase the number of previously infected people who will require only one vaccine dose rather than two.
More than 2.9 million vaccine 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.
Some 300,000 doses were administered last week, 280,000-300,000 this week and 250,000-270,000 will be given next week, according to Mr Reid.
Almost 132,000 tests for Covid-19 were carried out last week, with referrals up 10 per cent on the previous week. The positivity rate remained stable at 2.9 per cent.
A total of 224 cases have been identified in mandatory hotel quarantine, where 1,993 staff and 7,240 residents’ swabs have been carried out.
