Greece’s optimistic estimate that 95% of children are vaccinated according to the timelines prescribed by Greek and international medical protocols is overturned by one of the largest studies ever conducted in the country. The research reveals that approximately one in three children, during the first two critical years of life, is not fully vaccinated, a fact that leaves open the dangerous possibility of outbreaks in the wider population, even of diseases that many of us have forgotten.
The study, published in the scientific journal Vaccine, was based primarily on data from the electronic prescription systems of IDIKA (the Greek e-Government Center for Social Security Services) and EOPYY (the National Organization for Healthcare Services Provision). Associate Professor of Public Health Nursing at the University of Athens, Georgia Kourlaba, who is also the lead author of the study, explains to To Vima that this methodology and the analysis of the collected data helped fill a serious recording gap, since the National Childhood Vaccination Registry has existed since 2022, but many pediatricians never completed it.
“In a report by the World Health Organization in 2024, it was clearly stated that Greece needed research data because there were no reliable data on vaccination coverage,” she says. “The 95% figure that was often mentioned in discussions was a verbal estimate that was not based on actual data, and there was a need for data reflecting the real picture. In our study, we essentially collected all vaccine prescriptions issued between January 1, 2018, and October 31, 2024, for children born between 2018 and 2022. In other words, we recorded how children were vaccinated during the first two years of their lives,” she explains.
Research Findings
The study included a total of 400,959 children, and the results showed a gradual improvement in vaccination coverage over time.
What do the results show?
For the DTaP–IPV vaccine (diphtheria, tetanus, pertussis, and polio), full coverage with four doses reached 77.3%, while timely vaccination was approximately 70%. The proportion of unvaccinated children declined from about 3.4% to 2.4%.
For the Hib vaccine (Haemophilus influenzae type b), coverage reached 76.4%, with timely vaccination at around 69.6% and unvaccinated children at about 3.6%.
Average coverage for hepatitis B reached 88.6%, while timely vaccination stood at 76%.
For the MMR vaccine (measles, mumps, and rubella), the first dose covered approximately 87% of children, approaching the 90% target by 2024, while timely vaccination reached 83.9%.
For chickenpox (varicella), first-dose coverage was 81.5%, with timely vaccination at 80.5%.
Coverage for meningococcal C approached 90%, with timely vaccination reaching 88.4%.
For the pneumococcal vaccine (PCV), three-dose coverage was high, at around 87%, but the booster dose (the fourth dose) showed significant delays, with coverage falling to around 50%.
Overall, full coverage for the recommended schedule of seven vaccines reached 66.7%, timely completion stood at 46.4%, and completely unvaccinated children accounted for 3.1%.
The highest rates were recorded in Crete and Western Macedonia, while the lowest were found in the North Aegean. Children born outside Greece showed lower vaccination coverage, likely due to delayed access to the healthcare system and social barriers.
A Complex Reality
The conclusions are nuanced: Greece is not experiencing a collapse in vaccination coverage, nor is there a widespread anti-vaccination movement among children. However, for the first time, real data reveal a significant deficit in the completion of booster doses, leaving a large percentage of children only partially protected.
According to the World Health Organization’s targets, vaccination coverage should exceed 90% for most vaccines and 95% for measles in order to achieve herd immunity and prevent outbreaks. Greece appears to be approaching these targets for the initial doses but lags significantly behind when it comes to boosters.
“There appears to be negligence regarding booster doses,” says Ms. Kourlaba. “This is not a formal or procedural issue but a substantive matter of protection. Booster doses exist because they are necessary and must be administered at the prescribed time. The National Immunization Program is based on international guidelines. Therefore, when a child does not receive a booster dose, that child remains vulnerable.”
Why Small Outbreaks Occur
The deviations from WHO targets may help explain why Greece continues to experience occasional small outbreaks of diseases that, in theory, should be under control.
“For measles, we are slightly below the target, and this may explain why we continue to see sporadic cases and small outbreaks. The same applies to pertussis (whooping cough),” Ms. Kourlaba explains.
Professor of Pediatrics at the University of Athens Ioanna Pavlopoulou, who is also a member of the National Vaccination Committee, shares a similar view.
“We may not be experiencing an outbreak right now, but every three or four years we see measles outbreaks. Therefore, we need to intensify vaccination efforts,” she emphasizes.
She believes that the problem is not primarily related to organized vaccine refusal, but rather to delays and negligence.
Major Geographic Inequalities
Another interesting finding of the study is the significant variation between different regions of the country.
Crete and Western Macedonia show some of the highest vaccination coverage rates, while the lowest rates are recorded on the islands of the North and South Aegean.
Experts believe that mapping these differences can help guide more targeted public-health interventions.
The researchers note that the study has certain limitations, although they believe these do not substantially alter the overall picture. Specifically, the study does not include vaccinations administered through private payment and handwritten prescriptions, children without insurance coverage, or vaccinations carried out outside the electronic system. Nevertheless, pediatricians believe that this proportion is now relatively small.
The New Vaccination Registry
The National Vaccination Registry is expected to play a pivotal role going forward.
As Ms. Pavlopoulou explains, until recently many pediatricians did not complete it systematically. Now, however, registration has effectively become mandatory.
“It has now become mandatory because prescriptions cannot be issued unless previous information has been entered. The important thing is that, for the first time, we have the ability to see in real time where vaccination rates are low and intervene in a targeted manner.”
One of the proposals currently being considered is the introduction of automated reminders for parents.
“That is why we proposed SMS reminders through the Registry—to inform parents when the next dose is due,” Ms. Pavlopoulou continues.
The overall conclusion of the experts is that Greece remains in a better position than several other countries, but it still does not fully meet the WHO targets. And that, experts warn, is enough to maintain “cracks” in herd immunity among the pediatric population.
