Pharmacies across Ireland reported that their phones were ringing off the hook on Friday after the news of the country's accelerated vaccine rollout was announced.
Thousands of people are set to receive their inoculations sooner than expected after the expansion and acceleration of the rollout was confirmed.
From Monday, people aged 18 to 34 will have the option of "opting-in" to get a single-dose Johnson & Johnson jab from pharmacies.
Some 700 pharmacies nationwide will start vaccinating young people with the Janssen vaccine, with supplies of around 53,000 doses currently available.
The HSE said there are an additional 70,000 doses available at short notice "if needed".
The Deputy Chief Medical Officer added that everyone in Ireland who wants a coronavirus vaccine will likely be able to get one by the end of August.
Dr Ronan Glynn said there may be short-term issues with booking appointments in the coming weeks, while the Health Minister Stephen Donnelly stated that younger people wanting an mRNA vaccine may have to wait some time.
The Pfizer vaccine is administered in two doses around 28 days apart. You are classed as fully vaccinated seven days after your second jab – a minimum of 35 days after your first.
Moderna is also administered in two doses around 28 days apart, with people classed as fully vaccinated 14 days after their second dose – a minimum of 32 days after the first.
Two doses of AstraZeneca are needed, with the wait time between injections now down to four weeks. After having both doses, most people will have immunity and it takes 15 days after getting the second dose to have the best protection.
J&J is a single jab with people classed as fully vaccinated 14 days later.
Here's when the different age cohorts can expect to receive their vaccine in light of Friday's announcement:
18 to 34 age group
From July 5th, 18 to 34-year-olds will have the option to get a Johnson & Johnson, single-dose shot from pharmacies.
It comes after the National immunisation Advisory Committee (NIAC) reduced the age limit on the two adenovirus-based jabs.
NIAC still recommends that if you are in this age cohort, you should get an mRNA vaccine like Pfizer or Moderna.
However, if you don't want to wait to be offered one, you can choose to 'opt in' to get a Janssen jab in a pharmacy.
People are advised to book an appointment in advance from their local pharmacies as walk-ins will not be accepted.
It is expected that after registering, they will be called for their appointment within three weeks.
Vaccination centres will subsequently begin vaccinating younger age groups from mid-July in line with the current age-based rollout plan.
The AstraZeneca and Janssen vaccines, as well as the mRNA inoculations, will be administered at centres.
People aged 18 to 34 can get a Janssen single-dose COVID-19 vaccine in a pharmacy from Monday 5 July. For more information and to see the list of participating pharmacies, visit: https://t.co/tOr1mvSL5W #ForUsAll pic.twitter.com/6e5rDOgsaJ
— HSE Ireland (@HSELive) July 2, 2021
According to the HSE, "in mid-July online registration will be updated with functionality to allow younger age groups to opt-in to receive a Janssen and AstraZeneca vaccine from a vaccination centre if they choose to".
Meanwhile, online registration for people aged 30 to 34 year olds through vaccination centres will open on July 9th.
Online registration will subsequently open for people aged 25 to 29 and 18 and 24 "in due course".
Adults under the age of 35 who wish to wait for an mRNA vaccine will have to wait a few weeks.
The Health Minister Stephen Donnelly said the vaccine portal for younger cohorts to access the Pfizer or Moderna vaccines will not open until August.
35 to 39 age group
People can currently register for their COVID-19 vaccine if they are aged 35 or older.
However, the HSE confirmed that people in the 35 to 39 age group will not be able to avail of their COVID-19 vaccine in pharmacies.
This is because they are on "the brink" of receiving an mRNA vaccine, such as Pfizer or Moderna, which according to NIAC is the preferable jab for that cohort.
It means that around 145,000 people awaiting a vaccine appointment are unable to go to their pharmacy to get one.
Friday's announcement also leaves people aged between 35 and 49 as the only adults who are unable to get the single-shot J&J jab.
Many have been waiting weeks for their vaccine appointment and will now be waiting a minimum of 35 more days until they are fully vaccinated.
While it is unclear how long they may have been waiting, the HSE said it aims to offer people appointments within three weeks of registering.
People over 40
Everyone can register for their coronavirus vaccine if they are aged 35 or older.
You will get an appointment to be vaccinated at one of the country's vaccination centres, likely one to two weeks after you register.
People will receive a text with all the information they need to the mobile number you gave, three to five days before their scheduled appointment.
As with the 18 to 34 age group, people aged 50 and over can make an appointment to get their COVID-19 vaccine at a local pharmacy.
From July 12th, people in this group who have previously registered for an mRNA vaccine can choose to 'opt in' for an earlier J&J or AstraZeneca vaccine at a vaccination centre.
The Health Minister also confirmed that people waiting for their second dose of AstraZeneca will have been administered a second shot by July 12th.