A novel measles outbreak control strategy in the Netherlands in 2013-2014 using a national electronic immunization register: A study of early MMR uptake and its determinants.

BACKGROUND: During a large measles outbreak in the Netherlands in 2013-2014, infants aged 6-14months living in municipalities with low (<90%) measles-mumps-rubella (MMR) coverage were individually invited for an early MMR using the national electronic immunization register, Præventis. We estimated uptake of early MMR prior to and during the 2013-2014 outbreak and assessed determinants for early MMR vaccination. METHODS: We obtained vaccination records from Præventis, and defined early MMR as vaccination before 415days (13months) of age. A multi-level multivariable logistic regression model, restricted to infants with three diphtheria-pertussis-tetanus-polio (DPTP) vaccinations was used to examine the association between early MMR uptake and sex, parents' country of birth, socioeconomic status (SES; at postcode level) and voting proportions for the Reformed Political Party (SGP; at municipal level), used as a proxy for religious objections towards vaccination. RESULTS: In the 29 municipalities with low MMR coverage, uptake of early MMR was 0.5-2.2% prior to the outbreak. Between July 2013 and March 2014, 5,800 (57%) invited infants received an early MMR. Among infants with three DPTP, 70% received an early MMR. Only 1% of infants without prior DPTP received an early MMR. Lower early MMR uptake was associated with a higher SGP voter-ship (OR 0.89 per 5% increase, 95%CI 0.83-0.96), parents' with unknown country of birth (OR 0.66 95%CI 0.47-0.93) and compared with very high SES, high SES had significantly lower early MMR uptake (OR 0.66 95%CI 0.50-0.87). DISCUSSION: This is the first study describing use of Præventis during an outbreak and to assess determinants of early MMR uptake. More than half of invited infants obtained an early MMR. SES, parents' with unknown country of birth and religious objections towards vaccination were found to be associated with lower early MMR uptake. In future outbreaks, these determinants could be used to tailor intervention strategies.

Scale-up for bulk production of vaccine against meningococcal disease.

At the Netherlands Vaccine Institute (NVI) a vaccine against Neisseria meningitidis serogroup B organisms based on different porA subtypes contained in outer membrane vesicles (OMVs) is in advanced stage of development and will be evaluated in clinical trial studies in the near future. In order to meet the expected demand for product, the current biopharmaceutical production process is being scaled-up. This study describes the scale-up approach for the upstream process and the resulting bioreactor design and operation strategy leading towards a feasible solution for bulk production of a vaccine against meningococcal disease. The technically realized 1.2 m(3) bioreactor, equipped with a turbine impeller for gas dispersion, was complemented with an upward pumping impeller and a rotary plate foam breaker to contain foam inside the bioreactor. Aeration and ventilation in the culture broth were controlled by increasing the stirrer speed and gas flow rate simultaneously at increasing oxygen demand. The scale-up was successful and comparable growth curves and nutrient consumption profiles were reached on 0.06 and 1.2 m(3).