Study population characteristics
A total of 680 subjects, aged over 19 years, were surveyed among all patients who attended 6 laboratories during the study period. Median age was 60 years (min: 20, max: 91), and the gender ratio (M/F) was 0.68. Pensioners (56.9%) were the most commonly-represented occupational group, followed by business executive and managers (11.6%), the unemployed, disabled or students (8.0%), healthcare professionals (9.3%), labourers (3.1%), artisans-shopkeepers-business people (0.9%) and farmers (0.4%). Master’s degree (20.6%) was the most frequently-found educational level. Healthcare professionals who administered vaccinations were, in the great majority of cases, family physicians (77%), vaccination centres (9.6%), occupational physicians (8.8%), hospital centres and nurses (0.8%).
In the specific case of pertussis, 15.6% of subjects intended to become parents shortly after the survey, 8.2% were pregnant (or their partner was), and 19.1% had frequent contact with children under 6 months of age. On interview, a third of people who intended to become parents, a third of pregnant women (or their partners) and a third of people in contact with children under 6 months of age thought about getting vaccinated against pertussis. Twenty-nine percent were aware of the value of pertussis vaccination, and 21% of them knew how serious pertussis infection was in adults.
Finally, a total of 33.1% (225/680) of those surveyed reported having vaccination documentation. This documentary evidence assumed different forms: vaccination record (52.9%), vaccination card or certificate (34.2%), and personal health record (12.9%). Table
describes the characteristics of study subjects and the Lyon city population.
Characteristics of individuals with documentation and of the Lyon city population for dTPaP VC evaluation, October 2010-February 2011
Concerning self-reported vaccination, those who produced documentation, as opposed to those who did not, were predominantly women (64.4% vs 56.7%, p=0.05), older people (mean age: 60.7 vs 55.5 years, p=0.001) and people who thought they were up to date with their vaccinations apart from pertussis vaccination (Table
Self-reported vaccination of Lyon city subjects producing documentation or not, October 2010-February 2011
Vaccine coverage by age
Verification of vaccinations confirmed by documentary evidence (n=225) showed VC of 57.8% for diphtheria, 78.7% for tetanus, 63.6% for poliomyelitis and 10.7% for pertussis (Table
). VC for each of the 4 valences studied did not vary with gender. VC for diphtheria and poliomyelitis, but not for tetanus or pertussis, decreased significantly with age (Table
). For confirmed vaccinations, 128 people received combined dT-IPV vaccination (vaccines injected on the same day and in a single dose: dT-IPV and dTaP-IPV are the most commonlyadministered vaccines in France). VC with combined vaccination did not differ significantly with gender, but decreased with age. Some people received a single valence (tetanus), for which a VC gradient with age was observed (Table
Vaccination coverage and vaccine combination by age, Lyon city, October 2010-February 2011
Since the publication of pertussis recommendations in March 2008, VC rates appear to have increased (data not reported) but no pregnant women (0/11) in our study were up to date with their pertussis vaccination. No significant difference for pertussis vaccination appeared between men and women (p: 0.50). Moreover, 4% (1/26) of subjects intending to become parents were vaccinated, and 16% (6/36) of those in contact with infants under 6 months of age were vaccinated.
Vaccine status according to documentation reported or not
Subjects who thought the most that they were up to date with vaccination, compared to those were not, provided documentation (81%/60%, p<0.001). In total, people with documentation believed that they were up to date with their vaccinations, 70.2% for diphtheria, 95.6% for tetanus, 76.0% for poliomyelitis, and 22.2% for pertussis.
Comparison of confirmed and reported vaccinations by subject revealed that some who thought they were vaccinated for diphtheria; tetanus; poliomyelitis and pertussis were actually not (Table
). Conversely, some subjects who thought they were not vaccinated were up to date with their vaccinations.
Reported vaccinations (RV) versus confirmed vaccinations (CV), Lyon city, October 2010-February 2011