The Government has approved the mixing of Covid vaccines in limited circumstances.
It comes as NIAC is due to advise on a potential vaccine booster campaign to start in September.
NIAC has been deliberating on the mixing of vaccines for months and issued advice to the Government this morning.
It said vaccine doses can be mixed in very limited circumstances - meaning a first dose of AstraZeneca could be followed by a second of Pfizer or Moderna for example.
However, it will only be in cases where someone had a reaction to dose one or has serious concerns about taking a second shot of the same vaccine.
Work has begun between the HSE and the Department of Health to put the plans into action.
NIAC's next piece of advice is due next week - on whether or not to go ahead with a booster campaign of vaccines this autumn.
The WHO has appealed to richer countries to delay boosters in order to get the developing world vaccinated.
If any programme did go ahead here it would likely start at the end of September.
