Prompt effect of replacing the 7-valent pneumococcal conjugate vaccine with the 13-valent vaccine on the epidemiology of invasive pneumococcal disease in Norway.

The introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in the childhood immunisation programme in Norway in 2006 substantially decreased the incidence of vaccine-type (VT) invasive pneumococcal disease (IPD) in all age groups. Additionally, a slight increase in the non-vaccine (NVT) serotype IPD incidence (serotype replacement) was observed. After replacing PCV7 with PCV13 in 2011, a further decrease in IPD incidence is expected. However, the protection by the six additional serotypes opens new nasopharyngeal niches for colonisation, which favours conditions for serotype replacement. Close monitoring of IPD therefore remains important in order to quickly detect changes. In this observational retrospective population-based cohort study we used data notified nationally between 1 January 2004 and 31 December 2012 to determine the VT- and NVT-IPD incidences. The diversity in serotype distribution per year was analysed using the Simpson's index of diversity. Immunisation history of young children was obtained from the Norwegian Vaccination Registry to determine vaccine failure. The incidence of VT-IPD decreased in the targeted (<5 years) and non-targeted (≥5) age groups since PCV7 introduction and further decreased after the replacement with PCV13. Only two cases of vaccine failure were identified. This indicates very high effectiveness of the 2+1 schedules with PCV7 or PCV13 and suggests that non-vaccinated individuals profit through indirect protection. The decrease in incidence of PCV7-IPD in non-targeted age groups became larger in later years, indicating a lag phase for the indirect effects, and suggests that the indirect protection of PCV13 will increase in coming years. The incidence of some NVT, specifically serotypes 23B and 15A, increased after PCV13 introduction. This coincided with an increased Simpson's index of diversity in the targeted age group. As this suggests that serotype replacement is again occurring, continues monitoring of IPD is important so that adaptations to vaccine recommendations can be promptly issued.

Tracking parental attitudes on vaccination across European countries: The Vaccine Safety, Attitudes, Training and Communication Project (VACSATC).

The paper presents the first results from the European project VACSATC which aimed to track parental attitudes on vaccinations across several European countries. We compared five cross-sectional surveys of parents with children less than 3 years of age in England, Norway, Poland, Spain and Sweden carried out during 2008-2009. Data were collected from 6611 respondents. Two countries used face-to face interviews, one used telephone interviews, and two other countries used mail-in questionnaires. In all countries health professionals were indicated as the most important and trusted source of information on vaccination. The study results also show that parental attitudes on vaccinations in the childhood vaccination programs are generally positive. However, there were differences in attitudes on vaccination between the five countries, possibly reflecting different methods of sampling the respondents, context-specific differences (e.g. level of activity of governmental agencies), but also individual-level parental variation in demographic and socioeconomic status variables.

[Adverse events after vaccination]. / Uønskede hendelser etter vaksinering.

When the diseases we try to prevent through vaccination are rare, we tend to focus more on the associated risks. Vaccination has led to unfortunate consequences, mainly due to production failure and inadequate control in earlier years. The requirements for vaccine control are now so rigorous that the risk for such occurrences is close to zero. Local and mild systemic reactions to vaccines are rather common, and are usually well known and described in detail when a vaccine is licensed. Some vaccine reactions are however so rare that they only will be discovered through surveillance after the vaccine has become available for routine use. Suspicion of adverse events will now normally arise through the official notification systems for adverse events. Large epidemiological studies are often necessary to decide whether there is a causal relationship or only a coincidence. Recording of adverse events following vaccination and transparency about their existence, are important issues in the work to maintain the credibility of vaccines.

[Vaccination--value for money?]. / Vaksinering--er det verdt pengene?

Modern vaccines may be very costly, and society needs to consider vaccination against other preventive and curative interventions. An economic assessment of health care programmes implies to quantify costs and assess health consequences in order to set better priorities. The main challenge lies in obtaining valid estimates of health effects and side effects and the consequences of herd immunity and serotype shift. This article discusses the methods and challenges of economic evaluation of vaccination programs, with vaccination against whooping cough and pneumococcal disease as examples.

Cost effectiveness of adding 7-valent pneumococcal conjugate (PCV-7) vaccine to the Norwegian childhood vaccination program.

BACKGROUND: Streptococcus pneumoniae is a frequent bacterial cause of serious infections that may cause permanent sequelae and death. A 7-valent conjugate vaccine may reduce the incidence of pneumococcal disease, but some previous studies have questioned the cost-effectiveness of the vaccine. The aim of this study was to estimate costs and health consequences of adding this pneumococcal vaccine to the Norwegian childhood vaccination programme, taking the possibility of herd immunity into account. METHODS: We developed a simulation model (Markov-model) using data on the risk of pneumococcal disease in Norway, the efficacy of the vaccine as observed in clinical trials from other countries and adjusted for serotype differences, the cost of the vaccine and quality of life for patients with sequelae from pneumococcal disease. The results were expressed as incremental (additional) costs (in euros; euro1.00 approximately NOK8.37), incremental life years and incremental quality adjusted life years. Four different sets of main results are presented: costs and (quality adjusted) life years, with and without indirect costs (the value of lost production due to work absenteeism) and with and without potential herd immunity (i.e. childhood vaccination protects adults against pneumococcal disease). RESULTS: When indirect costs were disregarded, and four vaccine doses used, the incremental cost per life year gained was euro153,000 when herd immunity was included, and euro311,000 when it was not. When accounting for indirect costs as well, the cost per life year gained was euro58,000 and euro124,000, respectively. Assuming that three vaccine doses provide the same protection as four, the cost per life year gained with this regimen was euro90,000 with herd immunity and euro184,000 without (when indirect costs are disregarded). If indirect costs are also included, vaccination both saves costs and gains life years. INTERPRETATION/CONCLUSION: In Norway, governmental guidelines indicate that only interventions with cost per life year of less than euro54,000 should be implemented. This implies that four dose vaccination is not cost-effective even if decision makers includes both herd immunity and indirect costs in their decisions. If three doses offer the same protection as four doses, however, vaccination would be cost-saving when indirect costs are included, but not with only herd immunity. COMMENT: In the autumn of 2005, the Norwegian Government decided to include PCV-7 in the vaccination program. This analysis was used by the Ministry of Health and Ministry of Finance during the decision process.