Covid-19 herd immunity needs 90% of people to be vaccinated, HSE says

Weighing up risk to children key to any mass inoculation programme, Dr Colm Henry asserts

Nine out of 10 people in the State will have to be vaccinated to reach herd immunity against Covid-19, a senior health official has suggested, raising the prospect of a mass vaccination programme for children.

Dr Colm Henry, the Health Service Executive's chief clinical officer, said the National Immunisation Advisory Committee (Niac) would have to weigh up the benefits of mass inoculation of children against any potential threat to them from the vaccine itself.

The new assessment comes as the Government faces pressure to publish new guidelines for indoor dining and drinking in restaurants and pubs which are due to resume on Monday.

Government officials continue to work with Attorney General Paul Gallagher on regulations that must be put in place to allow for the reopening of indoor hospitality. There was optimism in the Government on Thursday night that the guidelines would be ready on Friday.


On vaccines, Dr Henry said it had previously been estimated that inoculating just six in 10 of the population against coronavirus could provide wider protection for society. But the arrival of the “more transmissible” Delta variant meant “to reach that concept of herd immunity, which every country is far away from yet, the estimate has gone up to 85-90 per cent”.

If Ireland were to reach herd immunity through vaccination alone, Dr Henry said "by extension it would include the population [to be vaccinated] extending to children".

Virus vs vaccine

He said a balance would need to be considered between “what is a very low risk” to children from being infected by the virus “against any risks the vaccine may have in younger age groups”.

In recent days, the UK decided to only offer children over 12 a vaccine if they were at higher risk through underlying conditions or if they were living with someone who was at higher risk of serious illness through infection.

Authorities in the US recommend children over the age of 12 be vaccinated, and steps are already being taken to give children under 12 jabs by mid-winter.

The Niac is currently considering the prospect of extending the vaccine rollout to 12-15 year olds and the Government is awaiting its advice.

A Government source did not dismiss the estimated threshold for herd immunity outlined by Dr Henry but said that what was “most urgent” was opening up the vaccines for 16-17 year olds as this was already agreed.

Minister for Higher Education Simon Harris said on Thursday he expected the Covid-19 vaccine portal would open for 16-17 year olds from early August. Mr Harris said being vaccinated against the virus was not a requirement to go to third-level education in September but he would encourage students to receive the vaccine.

Guideline publication

Meanwhile, officials continue to work on the guidelines for indoor hospitality with less than three days to go until the planned reopening.

Vintners' Federation of Ireland chief executive Padraig Cribbin said it was "imperative" they were released on Friday "so that people can plan over the weekend for what's needed on Monday".

Adrian Cummins of the Restaurants Association of Ireland called for the guidelines to be published "as soon as possible".

There is to be a meeting between the Attorney General and the departments involved in finalising the plans on Friday morning. Mr Gallagher raised concern at Cabinet on Wednesday over some aspects of the required regulations like data protection, enforcement and the exclusion of non-vaccinated people. Government sources on Thursday night sought to play down the extent of those concerns.

An app for businesses to check a person's proof of vaccination or recovery from Covid is expected to be ready on Friday for restaurants and pubs to become familiar with over the weekend. Tánaiste Leo Varadkar told RTÉ the Government was "working full-tilt" to have the regulations in place for reopening "well in advance of Monday".