WHOOPING COUGH
Pertussis resurgence in Tuscany outlines importance of timely vaccination in Italy
Research analysing 2016-2024 data from all pertussis-related hospitalisations in Tuscany, Italy, finds a ninefold increase in pertussis cases in 2024 among children and adolescents
Pertussis, commonly known as whooping cough, is a vaccine-preventable disease which continues to circulate even in areas where vaccination coverage is high, and outbreaks may still occur. A study published in Eurosurveillance and conducted at Meyer Children’s Hospital in Florence, Italy, has found a sharp increase in hospitalisations for pertussis among children and adolescents (patients aged 16 years or under) in 2024. The findings highlight the critical role of not only adhering to vaccination schedules but also administering doses at the earliest opportunity to ensure a further reduction in cases and hospitalisations among children and adolescents.
Caused by the bacterium Bordetella pertussis, pertussis is a highly contagious respiratory infection that can affect individuals of all ages. While infants (children under one year of age) are most vulnerable to severe disease, recent trends have indicated a shift in the age profile of cases. After several years of low incidence from 2016-2023, Tuscany experienced a sharp rise in pertussis cases in 2024.
The study by Nieddu et al. used retrospective observational data of all pertussis-related hospitalisations from 2016 to 2024. The vaccination status of the participants was taken from a digital vaccination registry in the Tuscany region, which is updated daily by healthcare professionals and vaccination centres. For each patient, the time interval between the first eligible day for vaccine administration (when the vaccine could have been administered but was not) and the onset of disease was calculated. From this, the delay was calculated from the number of days between the eligible vaccination date and disease onset.
A ninefold increase in cases since 2016-2019
Between January and December 2024, 259 children and adolescents were hospitalised with laboratory-confirmed pertussis. Compared with data from 2016-2019, there was a ninefold increase in admissions of children and adolescents during the 2024 period. Of note, over half of these cases occurred in adolescents aged 10–16 years, while infants accounted for just 7% of cases. This contrasts with earlier outbreaks, where infants represented the majority of hospitalisations.
Timeliness of vaccination as essential as coverage
Tuscany has one of the highest pertussis vaccination rates in Italy, with 97.7% of two-year-olds and 75.8% of 16-year-olds being fully vaccinated. However, the study outlined that many patients had received their doses at the latest point in time within the recommended schedule. Among infants eligible for vaccination, delays averaged more than a month for the first three doses. For adolescents, the gap between eligibility for the booster (recommended from age 12) and disease onset often exceeded a year.
“Formal compliance with the schedule is not enough”, the authors note. “Timely administration could have prevented many hospitalisations”.
Most adolescents in the study had completed their early childhood vaccinations suggesting a waning immunity rather than vaccine refusal as the main driver for the increase in cases. The current Italian schedule allows the adolescent booster to be given anytime between 12 and 18 years, a window which this study suggests may be too wide.
Among infants too young to receive their first dose of pertussis vaccine (77 patients were younger than 1 year and 20 were younger than 2 months), none of the mothers had received the recommended pertussis vaccine during pregnancy, despite its availability free of charge across Italy. This highlighted another missed opportunity for protection.
Public health implications
According to the authors, these findings call for renewed public health messaging emphasising not just the importance of vaccination but also that it be done in a timely manner. Strategies could include reminders for families and healthcare providers, as well as campaigns to reduce vaccine hesitancy and vaccine fatigue. Strong and robust surveillance systems are also essential to detect and respond to emerging trends.
The authors conclude that to mitigate resurgence of pertussis and prevent future outbreaks, a combination of measures should be implemented such as “strict adherence to the immunisation schedule, prioritising administration of vaccines at the earliest eligible opportunity, and consideration of advancing the adolescent booster dose”.
Journal
Eurosurveillance
Method of Research
Data/statistical analysis
Subject of Research
People
Article Title
Bordetella pertussis in hospitalised children and adolescents, the impact of vaccination delay, Tuscany, Italy, 2016 to 2024
Article Publication Date
28-Aug-2025
Why a whooping cough outbreak hit one of Italy’s most vaccinated regions
The researchers said that while most children were vaccinated, delays in getting booster jabs caused their immunity to wane, allowing the bacteria that causes pertussis to take root.
Last winter, Tuscany was gripped with a whooping cough outbreak that sickened hundreds of children and hit the region hard despite having one of the highest vaccination rates in Italy.
After a few quiet years, child hospitalisations for pertussis, also known as whooping cough, surged ninefold in 2024 in Tuscany, the central Italian region that is home to cities like Florence and Pisa.
Nearly all two-year-olds and three-quarters of 16-year-olds in Tuscany are fully immunised against the highly contagious respiratory disease.
That prompted researchers from the European Centre for Disease Prevention and Control (ECDC) to launch an investigation. In a newly released study, they say that although most young people who got sick had been vaccinated, delays in getting the jabs had caused their immunity to wane, allowing the bacteria that causes pertussis to take root.
Italian health authorities recommend that children get four doses of the pertussis vaccine, at three months, five months, 11 months, and six years of age. Boosters are recommended between ages 12 and 18 and every 10 years in adulthood.
However, delays averaged more than a month for infants and more than a year for adolescents who were later hospitalised, according to the study published in Eurosurveillance, the ECDC’s medical journal.
“Even in children and adolescents formally considered up to date with their immunisations, earlier administration could have prevented hospitalisation,” the study authors said.
Italy is not the only country seeing a resurgence of whooping cough. Between January and March 2024, there were more than 32,000 cases reported across the European Union, Iceland, Liechtenstein, and Norway.
Large outbreaks are expected every three to five years, even in areas with high vaccination coverage, according to the ECDC.
Whooping cough is most dangerous for babies under one year old, but anyone can fall seriously ill. Infected people will initially have cold-like symptoms, and after about a week they may develop a persistent cough that makes it hard to breathe.
In Tuscany, an average of 28 children and adolescents were hospitalised for pertussis every year between 2016 and 2019, a level that surged to 259 in 2024. More than half of these cases were among children ages 10 to 16, with babies making up just seven per cent of cases.
The outbreak among older children and teenagers caught public health experts’ attention, given that most hospitalisations are typically among infants. Countries such as Denmark, Spain, and France also reported an unusually high number of cases among adolescents around this time.
For the study, researchers tracked the interval between Tuscan children’s eligibility for vaccination and when they were actually immunised. They could then compare this delay to the onset of disease for all pertussis-related hospitalisations between 2016 and 2024
Most adolescent patients had gotten their early childhood vaccinations, meaning their infections were probably tied to waning immunity rather than parents refusing to get their kids booster jabs, the researchers said.
They said the findings indicate parents should not only get their children vaccinated against whooping cough – they should do so at the “earliest eligible opportunity”.
They also suggested that Italy’s recommended window for adolescent booster jabs – anytime between 12 and 18 years of age – may be too wide.
“We consider this a missed opportunity for protection,” the researchers said.
Meanwhile, 20 of the hospitalised babies were too young to be immunised, and none of their mothers had been vaccinated while pregnant.
The ECDC recommended that Italy launch public awareness campaigns to combat vaccine hesitancy and vaccine fatigue, and issue reminders about upcoming vaccinations for parents and doctors alike.
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