Vaccine hesitancy, the legacy of Covid, and the ever increasing pressures our GP services are under are all believed to be contributing factors to Northern Ireland's declining pre-school vaccination rates.
That's according to a new report by the Northern Ireland Audit Office which shows that over the past seven years, 15000 children here have not been fully vaccinated against measles, mumps and rubella.
The same study also shows that 10200 children have not received all the recommended doses of Pneumococcal Conjugate Vaccine (PCV).
Particularly low uptake rates were identified in the Belfast area; one in three children have not been fully immunised against PCV since 2015 in the Belfast Health Trust.
At one toddler group in North Belfast, a grandmother told us she can understand why some parents aren't vaccinating their children.
"I think people have developed a huge fear of vaccination since Covid", Mary Lynch told UTV.
"I would just be afraid in case there's an outbreak of measles or childhood illness which could cause children to go blind.
"My friend nursed a child with measles in hospital and she said once you've done that as a nurse you would never not vaccinate, but I can understand both arguments."
Dr Alan Stout from the British Medical Association said education and awareness is key to improving the uptake rates.
"That's one of the core recommendations of this report is that it needs that education, it needs a re-triggering of some of that so that people are aware.
"I think we've all become complacent with some of these illnesses because we haven't seen them for so long.
"We definitely need to reset on some of the education."
In a statement responding to the report the Public Health Agency said: "Immunisation is the safest and most effective way of protecting against many serious diseases, and getting vaccinated is one of the most important things we can do to protect our health.
"Vaccines save lives.
"This decrease is down to a combination of people forgetting how serious diseases like measles or polio can be, as they have been dramatically reduced or disappeared altogether due to good vaccine uptake in the past, and also the additional disruption to the routine vaccination programme caused by the COVID-19 pandemic.
"The PHA strongly recommends that babies and children are vaccinated according to the Routine Childhood Immunisations Schedule.
"After clean water, vaccination is the most effective public health intervention in the world for saving lives and promoting good health, and therefore one of the most important things that any parent can do is get their child vaccinated and encourage them to continue this throughout their own lifetime.
"The PHA is currently undertaking work to promote the importance of the childhood immunisation programme to parents and in schools, addressing concerns and the reasons why children need to continue to be vaccinated in large numbers.
"More targeted interventions with multi-disciplinary teams to improve vaccination uptake among ‘harder to reach’ communities are also taking place.
"If you are unsure if your child is up to date with vaccinations, the easiest way to check is to look at your child’s red book or speak to your health visitor or GP.
"If your child has missed a vaccination, please contact your GP practice to book an appointment as soon as you can to make sure they have maximum protection against disease."
Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know.