Introduction: Rotavirus vaccine was introduced in Nicaragua in 2006 and was recommended with upper age limits for completing the first dose (by age 105 days) and the final dose (by age 223 days) for the three dose series to minimize age specific risk of intussusception following rotavirus vaccination. Several years after introduction, estimated coverage with rotavirus vaccine was lower compared to coverage for other recommended childhood immunizations. Methods: This was a retrospective cohort study which analyzed data from a previously conducted vaccine effectiveness study in Nicaragua from 2006 to 2010. It examined trends in adherence to the upper age limit restriction (of 105 and 223 days) for administration of rotavirus vaccine in children under 5 years of age in Nicaragua. Logistic regression was used to estimate an odds ratio (OR) of receiving rotavirus vaccine after the age limit, among children presenting to the clinic after the age limit. Multivariate models were constructed to identify other factors (apart from the age restriction) that are associated with the receipt of rotavirus vaccine after each age limit. Results: Among children receiving their 1st dose of pentavalent vaccine after the age limit of 105 days, the likelihood of simultaneously receiving rotavirus vaccine was decreased by 90 % (O.R = 0.1 (95%CI: 0.08, 0.16)) compared to children receiving their rotavirus vaccine before the age limit, as shown in Table 4. This pattern for dose 1 remained consistent over time. Among children receiving their 3rd dose of pentavalent vaccine after the age limit of 223 days, the likelihood of simultaneously receiving rotavirus vaccine was decreased by 40% (O.R = 0.6 (95%CI: 0.2, 0.8)) in 2006, 30 % (O.R = 0.7 (95% CI: 0.3, 0.4)) in 2007, 10 % (O.R = 0.9 (95% CI: 0.7, 1.2) in 2008 and (O.R = 3.8 (95%CI: 1.9, 7.2)) in 2009 compared to children receiving pentavalent vaccine before the age limit as shown in Table 4. For doses 1 and 3, among children receiving pentavalent vaccine after the respective age limits, the odds of receiving rotavirus vaccine was higher in other cities when compared to Managua. For dose 3 alone, maternal education was found to be positively associated with receiving rotavirus vaccine after the age limit of 223 days of age, and children diagnosed with pneumonia had a reduced likelihood of receiving this vaccine. Conclusions: This study found that age restrictions was associated with limited rotavirus coverage. The adherence to such restrictions, especially the third dose, waned over time, suggesting that physicians may have shown increased interest in assuring full rotavirus immunization, as experience with using the vaccine progressed over time.
Table of Contents
1. INTRODUCTION 1 1.1 Discovery 1 1.2 Epidemiology 1 1.3 Transmission 2 1.4 Clinical disease and treatment 2 1.5 Immunization recommendations 4 2. BACKGROUND 5 2.1 Vaccine effectiveness 5 2.2 Risk of intussusception 6 2.3 Upper age limit restrictions 6 3. METHODS 8 3.1 Aims 8 3.2 Data sources 8 3.3 Subject selection and Inclusion criteria 9 3.4 Exclusion criteria 9 3.5 Study Variables 11 4. RESULTS 12 5. DISCUSSION 15 6. REFERENCES 18 7. TABLES / FIGURES 21
About this Master's Thesis
|Committee Chair / Thesis Advisor|
|Trends in rotavirus vaccine administration ()||2018-08-28||