The rollout of the AstraZeneca vaccine in Ireland has been anything but smooth.
From supply issues to changing advice on who should receive it, it has been hard to keep up with the latest news on this particular Covid-19 vaccine.
Yesterday, National Immunisation Advisory Committee (Niac) made new recommendations regarding AstraZeneca which has once again changed how the jab will be rolled out in Ireland.
This latest news has left people with many questions and we have the answers for you right here.
Niac has recommended the suspension of the AstraZeneca vaccine for people under the age of 60. This includes those with medical conditions with very high or high risk of severe Covid-19 disease.
People who are over 60 years of age and have received one dose of AstraZeneca should be given their second dose 12 weeks later as originally scheduled.
Those who are under the age of 60 with a high-risk medical condition should also receives their second dose 12 weeks after the first jab.
However, those under 60 without a high-risk medical condition should have the interval between doses extended to 16 weeks.
Any person who developed unusual blood clots with low platelets after their first dose of AstraZeneca should not receive a second dose.
The European Medicines Agency (EMA) last week confirmed a link between the vaccine and very rare blood clots, but stressed the benefits of the vaccine outweigh the risks.
The EMA made the decision to list unusual blood clots with low blood platelets as a very rare side effect of the AstraZeneca vaccine.
The safety committee found there was a possibility of very rare cases of blood clots combined with low levels of blood platelets occurring within two weeks of vaccination.
To date, most of the cases reported have occurred in women under the age of 60 within two weeks of the vaccine being administered.
Based on the currently available evidence, specific risk factors have not been confirmed.
Last week, the World Health Organisation (WHO) found a causal relationship between the vaccine and the occurrence of blood clots with low platelets to be plausible but not confirmed. It said specialised studies are required to fully understand the potential relationship between the two.
The subcommittee of the WHO Global Advisory Committee on Vaccine Safety (GACVS) is continuing to gather and review data.
It said the while reports of blood clots are concerning, the incidents under assessment are very rare.
In the UK, regulators have recommended that people aged 18 to 29 should be offered alternatives to the AstraZeneca vaccine.
Germany, Spain, the Netherlands and Italy have all limited the use of the vaccine to people over the age of 60.
Only people aged 65 and over will receive the jab in Finland and Sweden.
France and Belgium said the shot should only be administered to those age 55 and over.
In the US, they look to have enough vaccine doses to vaccinate everyone in the United States without requiring any AstraZenca.
Dr Anthony Fauci, the top US infectious disease expert, said whether or not they choose to use AstraZeneca is unclear but it looks like they won't need it.
"It is not a negative indictment of AZ – it just possible that, given the supply we have from other companies, that we may not need to use an AZ vaccine," said Dr Fauci.
The AstraZeneca vaccine was to play a key part in the national rollout, with 813,000 doses expected by the end of June.
Since the start of February, 233,710 AstraZeneca shots were given, with a 12-week lag to the second dose.
Vaccinations for the over-70s will not change as this group only receives the Pfizer-BioNTech or Moderna jabs.
Acting Chief Medical Officer, Ronan Glynn, has said limiting the use of the AstraZeneca vaccine to over 60s "will likely have an impact" on the country's vaccine programme but the extent is yet to be seen.
"The HSE will be looking at how to effectively reallocate vaccine so it is not necessarily the case that this will have a material impact or delay on the rollout of the programme at a population level," said Dr Glynn.
"I think we need to give the HSE at least a couple of days to model the impact of this."
Public health advice remains that people should accept whichever vaccine they are offered.
Professor Karina Butler, head of Niac, said people should understand that the vaccines are safe and effective.
Prof Butler said people should be "absolutely confident" that taking the vaccine offered to them is the very best thing for them to do.
"Any risk associated with a vaccine are really infinitesimal compared to the risks from Covid-19," said Prof Butler.
According to the EMA, patients should seek medical assistance immediately if they have the following symptoms after receiving the vaccine:
- shortness of breath
- chest pain
- swelling in your leg
- persistent abdominal (belly) pain
- neurological symptoms, including severe and persistent headaches or blurred vision
- tiny blood spots under the skin beyond the site of injection