Vaccination coverage among adolescents in certain provinces of Greece

Vaccine coverage in children, adolescents and adults with type 1 diabetes and their close contacts in Crete

BACKGROUND

Individuals with type 1 diabetes (T1D) are at increased risk of infections from vaccine-preventable diseases. This study focuses on compliance of T1D patients to the recommended vaccination schedule, vaccination of their close contacts for influenza and on factors potentially contributing to vaccination program deviations.

METHODS

The study population comprised children, adolescents and adults with T1D under follow-up at the Department of Pediatrics University Hospital and the Diabetic Center General Hospital, Heraklion, Crete-Greece. Data were extracted, following informed consent, from individual's vaccination booklet, medical files and telephone interview. Vaccination records, demographic parameters, glycemic control and influenza vaccination of close contacts were assessed.

RESULTS

The study included 258 participants (111 children/adolescents, 147 adults). Vaccination coverage for influenza was 76.7% for children, 64.4% for adults, for PCV 90.9% for children, but only 10.8% for the 23-valent, for hepatitis B 99% for children and 78.2% for adults. Youngsters were vaccinated against Hib 91.9%, meningococcus C 98.2%, measles-mumps-rubella 90.3%, chickenpox 86.4%, hepatitis A 76.5% and HPV 42.5%. Less than 65% of all individuals were fully vaccinated for diphtheria-tetanus-pertussis and meningococcus ACWY. Approximately 50% of the 605 close contacts were not vaccinated against influenza. Individuals with better glycemic status seemed to adhere to the recommended schedule and had a better vaccinated family environment.

CONCLUSIONS

Vaccination coverage for T1D individuals was sufficient regarding the majority of routine childhood vaccines, but less for adolescence and group-specific vaccines. Their family contacts were not sufficiently vaccinated for influenza. Targeted interventions are required in order to increase vaccination rates.

Vaccination coverage among adolescents and risk factors associated with incomplete immunization

The compliance with vaccination recommendations in adolescence has not been well documented in Greece. The aims of the present study were to estimate the vaccination coverage in a sample of adolescents and to identify risk factors associated with incomplete immunization. Α total of 1,005 adolescents aged 11 to 19 years who were outpatient visitors at an Adolescent Health Unit were included in this study. Participation required parental presence and consent and presentation of the official Child Health Booklet, from which immunizations were transcribed. The highest coverage rates were observed for childhood immunizations: poliomyelitis and hepatitis B (both 96%), measles/mumps/rubella (MMR; 93.1%), and meningitidis C (MenC; 83.4%). By contrast, lower rates were shown for the booster dose of tetanus/diphtheria/pertussis (39.6%), for hepatitis A (HAV; 59.1%), for the varicella vaccine (13.8% among adolescents without disease history), and among girls for the human papillomavirus vaccine (11.9%). We found a significant association between age and series completion for MMR, MenC, and HAV, with lower uptake among older adolescents . Overall, 22.7% of study participants were fully vaccinated according to criteria employed. In particular, non-urban residents, non-nationals, and females had lower likelihood of being fully vaccinated. In conclusion, our findings suggest suboptimal vaccination coverage among our sample's adolescents, mandating that every effort should be made to increase uptake, particularly among the geographically dispersed and the culturally diverse and female adolescents.

Vaccination coverage in 14-year-old adolescents: documentation, timeliness, and sociodemographic determinants

OBJECTIVE

The objective of this study was to measure the coverage and influencing determinants of hepatitis B virus, measles-mumps-rubella, and Meningococcus serogroup C vaccination in 14-year-old adolescents in Flanders, Belgium, in 2005.

METHODS

A total of 1500 adolescents who were born in 1991 and were living in Flanders were selected with a 2-stage cluster sampling technique. Home visits to copy vaccination documents and complete a questionnaire on sociodemographic and other related factors were conducted by trained interviewers. Only documented vaccination dates were accepted. Missing data were, when possible, retrieved through medical charts of the School Health System.

RESULTS

For 1344 (89.6%) adolescents, a home visit was performed. Vaccination coverage was 75.7% for the third dose of hepatitis B virus, 80.6% for the first dose and 83.6% for the second dose of measles-mumps-rubella, and 79.8% for Meningococcus serogroup C. Only 74.6% of the adolescents had proof of 2 measles-mumps-rubella vaccines. Although 1006 (74.8%) adolescents had vaccination data available at home at the time of the interview, only 427 (31.8%) were able to show written proof of all studied vaccines. The probably underestimated coverage rates are well below World Health Organization recommendations, but timeliness of vaccinations was respected. Univariate logistic regression showed that unemployment of the father as proxy measure of socioeconomic status was detrimental for vaccination status, in contrast to partial employment of the mother, which was a favorable factor. Previously unreported determinants of lower coverage rates inferred from this study are single divorced parents, larger families (> or = 4 children), lower adolescent educational level, enrollment in special education, and repeating a grade.

CONCLUSIONS

Insufficient documentation is a major barrier in this vaccination coverage study. More attention should go to those with the lowest coverage rates, such as adolescents from large families, with separated parents, and with a lower socioeconomic background.