Impact and effectiveness of a conjugate vaccine against invasive pneumococcal disease in Finland-a modelling approach

The evaluation of the public health impact of a vaccination program is essential in monitoring its policy relevance. Vaccine impact (VI) is usually assessed in a before-after design, in which data on disease burden without vaccination program is required from a historical reference period. It takes into account the indirect effects and therefore aims to describe the public health performance of the vaccination program in the population. Vaccine effectiveness (VE), measured in parallel settings, quantifies the benefit for an individual of being vaccinated but does not address the indirect effects of a vaccination program. The motivation of this paper is to gain insight into patterns of how VI and VE have manifested under large-scale use of a ten-valent pneumococcal conjugate vaccine in Finnish children. We construct a simple pseudo-dynamic model that mimics typical post-vaccination trends in the incidences of pneumococcal carriage and invasive disease in children when the proportion of vaccine-type carriage decreases. In the context of the model, we define the parameters of interest for VI and VE and explore how their expected values evolve over time. For comparison, we demonstrate the application of VI and VE estimation by using register data

Social Distancing and SARS-CoV-2 Transmission Potential Early in the Epidemic in Finland

Background:Information about social mixing patterns under heavy social distancing is needed to model the impact of nonpharmaceutical interventions on SARS-CoV-2 transmission.Methods:We conducted a survey on daily person-to-person contacts during the early phase of the SARS-CoV-2 epidemic in Finland, one month after strong social distancing measures had been introduced nationwide. We defined a contact as exchange of at least a few words in proximity of another person. We also considered physical (“skin-to-skin”) contacts separately. Based on 3,171 reported contacts by 1,320 participants of 1–79 years of age, we estimated age-stratified contact matrices essential in modeling virus transmission.Results:Compared with contacts during prepandemic conditions, as learned from the Finnish part of the Polymod study, there was a 72% (95% credible interval, CI = 71, 74) reduction in the daily number of all contacts and a 69% (95% CI = 66, 73) reduction in the daily number of physical contacts in April 2020. The largest reduction, of almost 90%, occurred in physical contacts by individuals more than 70 years of age. The estimated reduction in the transmission potential of the virus attributable solely to reduced contact frequencies varied between 59% (whole population; physical contacts; 95% CI = 52, 68) and 77% (over 20-year olds; physical contacts; 95% CI = 70, 89).Conclusions:We surmise that the large reduction in the daily numbers of social contacts in the early part of the SARS-CoV-2 epidemic in Finland was likely a major contributor to the steady decline of the epidemic in the country since early April.</p

Lääkärin syntymäpäiviä vietetään useammin alkuvuodesta

Teema : syntymäPeer reviewe

Sustained reduction in vaccine-type invasive pneumococcal disease despite waning effects of a catch-up campaign in Kilifi, Kenya: A mathematical model based on pre-vaccination data.

BACKGROUND: In 2011, Kenya introduced the 10-valent pneumococcal conjugate vaccine together with a catch-up campaign for children aged <5years in Kilifi County. In a post-vaccination surveillance study based in Kilifi, there was a substantial decline in invasive pneumococcal disease (IPD). However, given the continued circulation of the vaccine serotypes it is possible that vaccine-serotype disease may re-emerge once the effects of the catch-up campaign wear off. METHODS: We developed a compartmental, age-structured dynamic model of pneumococcal carriage and invasive disease for three serotype groups: the 10-valent vaccine serotypes and two groups of non-vaccine serotypes based on their susceptibility to mutual competition. The model was calibrated to age- and serotype-specific data on carriage and IPD in the pre-vaccination era and used to predict carriage prevalence and IPD up to ten years post-vaccination in Kilifi. The model was validated against the observed carriage prevalence after vaccine introduction. RESULTS: The model predicts a sustained reduction in vaccine-type pneumococcal carriage prevalence from 33% to 8% in infants and from 30% to 8% in 1-5year olds over the 10-year period following vaccine introduction. The incidence of IPD is predicted to decline across all age groups resulting in an overall reduction of 56% in the population, corresponding to 10.4 cases per 100,000 per year. The vaccine-type IPD incidence is estimated to decline by 83% while non-vaccine-type IPD incidence is predicted to increase by 52%. The model's predictions of carriage prevalence agrees well with the observed data in the first five years post-vaccination. CONCLUSION: We predict a sustained and substantial decline in IPD through PCV vaccination and that the current regimen is insufficient to fully eliminate vaccine-serotype circulation in the model. We show that the observed impact is likely to be sustained despite waning effects of the catch-up campaign

Preterm birth and subsequent timing of pubertal growth, menarche, and voice break

Background We evaluated pubertal growth and pubertal timing of participants born preterm compared to those born at term. Methods In the ESTER Preterm Birth Study, we collected growth data and measured final height of men/women born very or moderately preterm (= 37 weeks, 131/151), resulting in median 9 measurements at >= 6 years. Timing of menarche or voice break was self-reported. Peak height velocity (PHV, cm/year) and age at PHV (years) were compared with SuperImposition by Translation And Rotation (SITAR) model (sexes separately). Results Age at PHV (years) and PHV (cm/year) were similar in all gestational age groups. Compared to term controls, insignificant differences in age at PHV were 0.1 (95% CI: -0.2 to 0.4) years/0.2 (-0.1 to 0.4) for very or moderately/late preterm born men and -0.0 (-0.3 to 0.3)/-0.0 (-0.3 to 0.2) for women, respectively. Being born small for gestational age was not associated with pubertal growth. Age at menarche or voice break was similar in all the gestational age groups. Conclusions Timing of pubertal growth and age at menarche or voice break were similar in participants born preterm and at term. Impact Pubertal growth and pubertal timing were similar in preterm and term participants in a relatively large cohort with a wide range of gestational ages. Previous literature indicates that small for gestational age is a risk for early puberty in term born children. This was not shown in preterm children. While our study had limited power for children born very preterm, all children born preterm were not at increased risk for early puberty.Peer reviewe

Migraine in children and adults born preterm : A nationwide register linkage study

Objective Being born preterm is related to adverse health effects later in life. We studied whether preterm birth predicts the risk of migraine. Methods In this nationwide register study, we linked data from six administrative registers for all 235,624 children live-born in Finland (January 1987 to September 1990) and recorded in the Finnish Medical Birth Register. n = 228,610 (97.0%) had adequate data and were included. Migraine served as primary outcome variable and was stringently defined as a diagnosis from specialised health care and/or >= 2 reimbursed purchases of triptans. We applied sex- and birth year-stratified Cox proportional hazard regression models to compute hazard ratios and confidence intervals (95% confidence intervals) for the association between preterm categories and migraine. The cohort was followed up until an average age of 25.1 years (range: 23.3-27.0). Results Among individuals born extremely preterm (23-27 completed weeks of gestation), the adjusted hazard ratios for migraine was 0.55 (0.25-1.24) when compared with the full-term reference group (39-41 weeks). The corresponding adjusted hazard ratios and 95% confidence intervals for the other preterm categories were: Very preterm (28-31 weeks); 0.95 (0.68-1.31), moderately preterm (32-33 weeks); 0.96 (0.73-1.27), late preterm (34-36 weeks); 1.01 (0.91-1.11), early term (37-38 weeks); 0.98 (0.93-1.03), and post term (42 weeks); 0.98 (0.89-1.08). Migraine was predicted by parental migraine, lower socioeconomic position, maternal hypertensive disorder and maternal smoking during pregnancy. Conclusion We found no evidence for a higher risk of migraine among individuals born preterm.Peer reviewe

Author Correction: School grades and educational attainments of adolescents and young adults born preterm

The original version of this Article contained an error in Figures 2, 3, 4 and 5, where the legend for the visual cues incorrectly states ‘Model 2’ for the black square. The correct legends now read: (Figure presented.) The original Figures 2, 3, 4 and 5 and their respective accompanying legend appear below. The original Article has been corrected

Risk-taking Behavior of Adolescents and Young Adults Born Preterm

Peer reviewe

School Grades and Educational Attainments of Adolescents and Young Adults Born Preterm

Attendance in special education (SE) is more common among individuals born preterm than among those born at term. Less is known about school grades of those born preterm in mainstream education (ME), and how these grades predict later educational attainment. This population-based register-linkage study assessed (1) attendance in SE, and then focused on those in ME by assessing (2) school grades at 16 year, (3) completed educational level at 25 year, and (4) school grades as predictors for completed education by gestational age (GA) with full-term birth (39-41 completed weeks) as reference. The sample comprised 223,744 individuals (10,521 preterm, 4.7%) born in Finland (1/1987-9/1990). Of the sample, 4.9% attended SE. Those born preterm had up to 5.5-fold rates for SE. In ME, those born extremely preterm (EPT) had marginally lower mathematics grades compared with full-term counterparts, whilst those born late preterm or early term had slightly higher grades. Those born EPT or very preterm had lower physical education grades in ME. However, the minor differences in school grades according to GA appear not to translate into educational differences in young adulthood. The associations between school grades at 16 year and completed education at 25 year did not vary by GA.Peer reviewe

Preterm birth and subsequent timing of pubertal growth, menarche, and voice break

Background: We evaluated pubertal growth and pubertal timing of participants born preterm compared to those born at term.Methods: In the ESTER Preterm Birth Study, we collected growth data and measured final height of men/women born very or moderately preterm (= 37 weeks, 131/151), resulting in median 9 measurements at >= 6 years. Timing of menarche or voice break was self-reported. Peak height velocity (PHV, cm/year) and age at PHV (years) were compared with SuperImposition by Translation And Rotation (SITAR) model (sexes separately).Results: Age at PHV (years) and PHV (cm/year) were similar in all gestational age groups. Compared to term controls, insignificant differences in age at PHV were 0.1 (95% CI: -0.2 to 0.4) years/0.2 (-0.1 to 0.4) for very or moderately/late preterm born men and -0.0 (-0.3 to 0.3)/-0.0 (-0.3 to 0.2) for women, respectively. Being born small for gestational age was not associated with pubertal growth. Age at menarche or voice break was similar in all the gestational age groups.Conclusions: Timing of pubertal growth and age at menarche or voice break were similar in participants born preterm and at term. Impact Pubertal growth and pubertal timing were similar in preterm and term participants in a relatively large cohort with a wide range of gestational ages. Previous literature indicates that small for gestational age is a risk for early puberty in term born children. This was not shown in preterm children. While our study had limited power for children born very preterm, all children born preterm were not at increased risk for early puberty.</p