Potato Consumption and All-Cause and Cardiovascular Disease Mortality - A Long-Term Follow-Up of a Norwegian Cohort.

BACKGROUND: Potatoes are a staple food in many traditional cuisines, yet their impact on long-term risk of cardiovascular disease (CVD) and mortality is unclear, hampering evidence-based dietary guidelines. OBJECTIVES: This study aimed to examine the association between potato consumption and all-cause and CVD-specific death over a substantial follow-up period within a cohort predominantly consuming boiled potatoes. METHODS: Adults from 3 Norwegian counties were invited to 3 health screenings in 1974-1988 (>80% attendance). Dietary data were collected using semiquantitative food frequency questionnaires at each screening to categorize weekly potato consumption (≤6, 7-13, or ≥14 potatoes/wk) and calculate daily cumulative mean intakes (grams/day). Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox regression to estimate HRs and 95% CIs for the association between potato consumption and risk of death from all causes, CVD, ischemic heart disease (IHD), and acute myocardial infarction (AMI). RESULTS: Among 77,297 participants with a mean baseline age of 41.1 y (range: 18.0-63.9 y), we observed 27,848 deaths, including 9072 deaths due to CVD, over a median follow-up of 33.5 y. Participants who consumed ≥14 potatoes/wk had a lower risk of all-cause death compared with those consuming ≤6 potatoes/wk (HR: 0.88; 95% CI: 0.84, 0.93). Potato consumption was associated with a minor, inverse risk of death due to CVD, IHD, and AMI. In continuous analyses of cumulative intakes, each 100 g/d increment was associated with 4% lower risk of death from all causes (HR: 0.96; 95% CI: 0.94, 0.98), CVD (HR: 0.96; 95% CI: 0.93, 0.99), IHD (HR: 0.96; 95% CI: 0.91, 1.00), and AMI (HR: 0.96, 95% CI: 0.91, 1.01). CONCLUSIONS: In this cohort with a generally high consumption of predominantly boiled potatoes, we find modest, inverse associations between potato consumption and death from all causes, CVD, and IHD.

Concurrent Infection With Multiple Human Papillomavirus Types Among Unvaccinated and Vaccinated 17-Year-Old Norwegian Girls.

BACKGROUND: Whether type-specific human papillomavirus (HPV) infection influences the risk of acquiring infections with other HPV types is unclear. We studied concurrent HPV infections in 17-year-old girls from 2 birth cohorts; the first vaccine-eligible cohort in Norway and a prevaccination cohort. METHODS: Urine samples were collected and tested for 37 HPV genotypes. This study was restricted to unvaccinated girls from the prevaccination cohort (n = 5245) and vaccinated girls from the vaccine-eligible cohort (n = 4904). Risk of HPV infection was modelled using mixed-effect logistic regression. Expected frequencies of concurrent infection with each pairwise combination of the vaccine types and high-risk types (6/11/16/18/31/33/35/39/45/51/52/56/58/59) were compared to observed frequencies. RESULTS: Infection with multiple HPV types was more common among unvaccinated girls than vaccinated girls (9.2% vs 3.7%). HPV33 and HPV51 was the only HPV pair that was detected together more often than expected among both unvaccinated (P = .002) and vaccinated girls (P < .001). No HPV pairs were observed significantly less often than expected. CONCLUSIONS: HPV33 and HPV51 tended to be involved in coinfection among both unvaccinated and vaccinated girls. The introduction of HPV vaccination does not seem to have had an effect on the tendency of specific HPV types to cluster together.

Effectiveness of mRNA Booster Vaccination Against Mild, Moderate, and Severe COVID-19 Caused by the Omicron Variant in a Large, Population-Based, Norwegian Cohort.

BACKGROUND: Understanding how booster vaccination can prevent moderate and severe illness without hospitalization is crucial to evaluate the full advantage of mRNA boosters. METHODS: We followed 85 801 participants (aged 31-81 years) in 2 large population-based cohorts during the Omicron BA.1/2 wave. Information on home testing, PCR testing, and symptoms of coronavirus disease 2019 (COVID-19) was extracted from biweekly questionnaires covering the period 12 January 2022 to 7 April 2022. Vaccination status and data on previous SARS-CoV-2 infection were obtained from national registries. Cox regression was used to estimate the effectiveness of booster vaccination compared to receipt of 2-dose primary series >130 days previously. RESULTS: The effectiveness of booster vaccination increased with increasing severity of COVID-19 and decreased with time since booster vaccination. The effectiveness against severe COVID-19 was reduced from 80.9% shortly after booster vaccination to 63.4% in the period >90 days after vaccination. There was hardly any effect against mild COVID-19. The effectiveness tended to be lower among subjects aged ≥60 years than those aged <50 years. CONCLUSIONS: This is the first population-based study to evaluate booster effectiveness against self-reported mild, moderate, and severe COVID-19. Our findings contribute valuable information on duration of protection and thus timing of additional booster vaccinations.

Influenza risk groups in Norway by education and employment status.

AIMS: This study aimed to estimate the size of the risk group for severe influenza and to describe the social patterning of the influenza risk group in Norway, defined as everyone ⩾65 years of age and individuals of any age with certain chronic conditions (medical risk group). METHODS: Study data came from a nationally representative survey among 10,923 individuals aged 16-79 years. The medical risk group was defined as individuals reporting one or more relevant chronic conditions. The associations between educational attainment, employment status, age and risk of belonging to the medical risk group were studied with logistic regression. RESULTS: Nearly a fifth (19.0%) of respondents reported at least one chronic condition, while 29.4% belonged to the influenza risk group due to either age or chronic conditions. Being older, having a low educational level (comparing compulsory education to higher education, odds ratio (OR)=1.4, 95% confidence interval (CI) 1.2-1.8 among women, and OR=1.3, 95% CI 1.1-1.7 among men) and a weaker connection to working life (comparing disability pension to working full-time, OR=6.8, 95% CI 5.3-8.7 among women, and OR=6.5, 95% CI 4.9-8.5 among men) was associated with a higher risk of belonging to the medical risk group for severe influenza. CONCLUSIONS: This study indicates that the prevalence of medical risk factors for severe influenza is disproportionally distributed across the socio-economic spectrum in Norway. These results should influence both public funding decisions regarding influenza vaccination and communication strategies towards the public and health professionals.

Impact and cost-effectiveness of strategies to accelerate cervical cancer elimination: A model-based analysis.

Following the global call for action by the World Health Organization to eliminate cervical cancer (CC), we evaluated how each CC policy decision in Norway influenced the timing of CC elimination, and whether introducing nonavalent human papillomavirus (HPV) vaccine would accelerate elimination timing and be cost-effective. We used a multi-modeling approach that captured HPV transmission and cervical carcinogenesis to estimate the CC incidence associated with six past and future CC prevention policy decisions compared with a pre-vaccination scenario involving 3-yearly cytology-based screening. Scenarios examined the introduction of routine HPV vaccination of 12-year-old girls with quadrivalent vaccine in 2009, a temporary catch-up program for females aged up to 26 years in 2016-2018 with bivalent vaccine, the universal switch to bivalent vaccine in 2017, expansion to include 12-year-old boys in 2018, the switch from cytology- to HPV-based screening for women aged 34-69 in 2020, and the potential switch to nonavalent vaccine in 2021. Introducing routine female vaccination in 2009 enabled elimination to be achieved by 2056 and prevented 17,300 cases. Cumulatively, subsequent policy decisions accelerated elimination to 2039. According to our modeling assumptions, switching to the nonavalent vaccine would not be considered 'good value for money' at relevant cost-effectiveness thresholds in Norway unless the incremental cost was $19 per dose or less (range: $17-24) compared to the bivalent vaccine. CC control policies implemented over the last decade in Norway may have accelerated the timeframe to elimination by more than 17 years and prevented over 23,800 cases by 2110.

Time trends in HPV vaccination according to country background: a nationwide register-based study among girls in Norway.

BACKGROUND: Since the human papillomavirus (HPV) vaccine was introduced in Norway in 2009, the vaccine uptake has increased. Whether this increase is similar regardless of the girls' country background is unknown. We examined changes in HPV vaccine uptake from 2009 to 2014 and studied the impact of parental education and income on HPV vaccine uptake according to country background. METHODS: Girls in the first six birth cohorts (1997-2002) eligible for HPV vaccination were identified through the National Registry. Information on HPV vaccination, country background and socioeconomic factors was extracted from the Norwegian Immunisation Registry and Statistics Norway. Risk differences (RDs) and confidence intervals (CIs) were estimated with linear binomial regression. A total of 177,387 girls were included in the study. RESULTS: The HPV vaccine uptake increased from 72.5% in 2009 to 87.3% in 2014. The uptake increased for girls in all country background categories. Highest vaccine uptake was observed in girls with East-/South-East Asian background, 88.9% versus 82.5% in the total population. Vaccine uptake decreased slightly with increasing parental education, RD = - 1.6% (95% CI: - 2.3% to - 0.8%) for highest compared with lowest education level. In contrast, the uptake increased with increasing household income, RD = 4.9% (95% CI, 4.3 to 5.5%) for highest compared with lowest quintile. Parental education had largest impact in girls with Asian background, RD = - 8.1% (95% CI - 10.5% to - 5.6%) for higher vs lower education. The largest impact of household income was observed in girls with background from Middle East/Africa, RD for a 200,000 NOK increase in income was 2.1% (95% CI 1.2 to 3.0%). CONCLUSIONS: The HPV vaccine uptake differed with country background but increased over time in all country background categories. Moreover, the impact of education and income on vaccine uptake differed with country background.

Milk drinking and risk of hip fracture: the Norwegian Epidemiologic Osteoporosis Studies (NOREPOS).

Milk provides energy and nutrients considered protective for bone. Meta-analyses of cohort studies have found no clear association between milk drinking and risk of hip fracture, and results of recent studies are contradictory. We studied the association between milk drinking and hip fracture in Norway, which has a population characterised by high fracture incidence and a high Ca intake. Baseline data from two population-based cohorts were used: the third wave of the Norwegian Counties Study (1985-1988) and the Five Counties Study (2000-2002). Diet and lifestyle variables were self-reported through questionnaires. Height and weight were measured. Hip fractures were identified by linkage to hospital data with follow-up through 2013. Of the 35 114 participants in the Norwegian Counties Study, 1865 suffered a hip fracture during 613 018 person-years of follow-up. In multivariable Cox regression, hazard ratios (HR) per daily glass of milk were 0·97 (95 % CI 0·92, 1·03) in men and 1·02 (95 % CI 0·96, 1·07) in women. Of 23 259 participants in the Five Counties Study, 1466 suffered a hip fracture during 252 996 person-years of follow-up. HR for hip fractures per daily glass of milk in multivariable Cox regression was 0·99 (95 % CI 0·92, 1·07) in men and 1·02 (95 % CI 0·97, 1·08) in women. In conclusion, there was no overall association between milk intake and risk of hip fracture in Norwegian men and women.

Substantial Decline in Prevalence of Vaccine-Type and Nonvaccine-Type Human Papillomavirus (HPV) in Vaccinated and Unvaccinated Girls 5 Years After Implementing HPV Vaccine in Norway.

Background: In 2009, quadrivalent human papillomavirus (HPV) vaccine was introduced in a school-based single-cohort program targeting 12-year-old girls in Norway. We estimated the impact of the Norwegian HPV immunization program. Methods: Three birth cohorts of 17-year-old girls, 2 nonvaccine-eligible cohorts (born 1994 or 1996) and 1 vaccine-eligible cohort (born 1997) were invited to deliver urine samples. The samples were analyzed for 37 HPV genotypes. HPV prevalence was compared between birth cohorts and between vaccinated and unvaccinated girls within and across birth cohorts after linkage to the Norwegian Immunisation Registry. Results: In total, 17749 urine samples were analyzed. A 42% (95% confidence interval [CI], 37%-47%) reduction in any HPV type and 81% (95% CI, 76%-85%) reduction in vaccine types (HPV-6/11/16/18) were observed in the vaccine-eligible cohort compared to the 1994 cohort. Vaccine types were reduced by 54% (95% CI, 39%-66%) and 90% (95% CI, 86%-92%) in unvaccinated and vaccinated girls, respectively, from the 1997 cohort, compared with unvaccinated girls born in 1994. A significant reduction was also observed for several nonvaccine types. Vaccine-type prevalence was reduced by 77% (95% CI, 65%-85%) in vaccinated compared with unvaccinated girls from the 1997 cohort. Conclusions: In this largely HPV-naive population, we observed a substantial reduction in vaccine and nonvaccine types in vaccinated and unvaccinated girls following introduction of HPV vaccination.

Risk of pregnancy complications and adverse birth outcomes after maternal A(H1N1)pdm09 influenza: a Norwegian population-based cohort study.

BACKGROUND: The effects of maternal influenza infection on the fetus remain unclear. We studied mild influenza and influenza antibodies in relation to birth weight and risks of pre-eclampsia, preterm birth (PTB), and small for gestational age (SGA) birth among the unvaccinated participants in the Norwegian Influenza Pregnancy Cohort. METHODS: Pregnant women attending a routine ultrasound were recruited from four hospitals in Norway shortly after the 2009 A(H1N1) pandemic. The present study was restricted to unvaccinated participants who were pregnant during the pandemic. Information on the participants was obtained through questionnaires and linkage with national registries. Maternal blood samples were collected at delivery. Women with laboratory-confirmed A(H1N1)pdm09 influenza, a clinical diagnosis of influenza, or self-reported influenza during the pandemic were classified as having had influenza. A(H1N1)pdm09-specific antibodies in serum were detected with the hemagglutination-inhibition assay. Detection of antibodies was considered an indicator of infection during the pandemic in the unvaccinated participants. Odds ratios were estimated with logistic regression. Quantile regression was used to estimate differences in the distribution of birth weight. RESULTS: Among the 1258 women included in this study, there were 37 cases of pre-eclampsia, 41 births were PTB, and 103 births were SGA. 226 women (18.0%) had influenza during the pandemic. The majority of cases did not receive medical care, and only a small proportion (1.3%) of the cases were hospitalized. Thus, the cases consisted primarily of women with mild illness. No significant associations between influenza and risk of pre-eclampsia, PTB, or SGA birth were observed. Detection of A(H1N1)pdm09-specific antibodies was associated with a lower 10th percentile of birth weight, ß = - 159 g (95% CI - 309, - 9). CONCLUSIONS: Mild influenza illness during pregnancy was not associated with increased risk of pre-eclampsia, PTB or SGA birth. However, influenza infection during pregnancy may reduce the birth weight of the smallest children.

Pre-diagnostic body mass index and weight change in relation to colorectal cancer survival among incident cases from a population-based cohort study.

BACKGROUND: Whether excess body weight influences colorectal cancer (CRC) survival is unclear. We studied pre-diagnostic body mass index (BMI) and weight change in relation to CRC-specific mortality among incident CRC cases within a large, Norwegian cohort. METHODS: Participants' weight was measured at health examinations up to three times between 1974 and 1988. CRC cases were identified through linkage with the Norwegian Cancer Registry. In total, 1336 men and 1180 women with a weight measurement >3 years prior to diagnosis were included in analyses. Hazard ratios (HRs) and confidence intervals (CIs) were estimated with Cox regression. RESULTS: During a mean follow-up of 5.8 years, 507 men and 432 women died from CRC. Obesity (BMI ≥30 kg/m(2)) was associated with higher CRC-specific mortality than normal weight (BMI 18.5-25 kg/m(2)) in men with proximal colon cancer, HR = 1.85 (95 % CI 1.08-3.16) and in women with rectal cancer, HR = 1.93 (95 % CI 1.13-3.30). Weight gain was associated with higher CRC-specific mortality in women with CRC, colon cancer, and distal colon cancer, HRs per 5 kg weight gain were 1.18 (95 % CI 1.01-1.37), 1.22 (95 % CI 1.02-1.45), and 1.40 (95 % CI 1.01-1.95), respectively. Weight gain was not significantly associated with survival in men. CONCLUSIONS: Maintaining a healthy weight may benefit CRC survival, at least in women.

Monitoring of timely and delayed vaccinations: a nation-wide registry-based study of Norwegian children aged < 2 years.

BACKGROUND: Delayed vaccinations increase the risk for vaccine preventable diseases (VPDs). Monitoring of delayed vaccinations by using a national immunisation registry has not been studied in countries recommending a two-dose (3 and 5 months of age) primary series of e.g., pertussis vaccine. Surveillance/monitoring of all vaccinations may improve vaccination programmes functioning. METHODS: We obtained information from the Norwegian immunisation registry (SYSVAK) on all programme vaccinations received at age up to 730 days in children born in 2010 (n = 63,382). Timely vaccinations were received up to 7 days after the recommended age. Vaccinations were considered delayed if they were received more than one month after the recommended age in the schedule. RESULTS: In vaccinated children, timely administration of the subsequent three doses of pertussis and one dose of measles occurred in 73.8, 47.6, 53.6 and 43.5 % respectively. Delay for one or more programme vaccinations (diphtheria, tetanus, pertussis, polio, Haemophilus influenza type B, invasive pneumococcal disease, measles, mumps or rubella) was present in 28,336 (44.7 %) children. Among those who were delayed the mean duration was 139 days. The proportion of children that had vaccinations delayed differed among counties (range 37.4 %-57.8 %). Immigrant children were more frequently delayed 52.3 % vs. 43.1 %, RR 1.21 (95 % CI 1.19, 1.24). Children scheduled for vaccines in the summer holiday month (July) were more frequently delayed than others (1(st) dose pertussis vaccine 6.5 % vs. 3.9 % RR 1.65 (95 % CI 1.48, 1.85). Priming against pertussis (2(nd) dose), pneumococcal (2(nd) dose) and measles (1(st) dose) was delayed in 16.8, 18.6 and 29.3 % respectively. CONCLUSION: Vaccinations were frequently delayed. Delayed vaccinations differed among counties and occurred more frequently during the summer vacation (July) and in the immigrant population. Monitoring improves programme surveillance and may be used on an annual basis.

Higher educational attainment associated with higher confidence in influenza vaccination in Norway.

AIMS: To explore public confidence in influenza vaccination through the use of attitudinal indicators, and study whether educational attainment is related to attitudes towards influenza vaccination. METHODS: Confidence in influenza vaccination was measured with three questions adapted from the Vaccine Confidence Project. These questions have been included in four study years of a Norwegian nationally representative telephone survey that cover influenza seasons 2016/17, 2019/20, 2020/21 and 2021/22. Over these four years, a total of 8 436 individuals aged 18-79 years responded to the survey and are included in the analysis. Risk differences (RDs) with 95 % confidence intervals were estimated using multivariable Poisson regression. RESULTS: Influenza vaccine confidence increased over time, with approximately 80 % of the general population expressing trust in the vaccine in the 2021/22 season. There was a tendency towards higher confidence in the oldest age group (65-79 years). Moreover, confidence increased with increasing educational attainment. The proportion of participants who agreed that influenza vaccine is compatible with their basic values was close to 20 percentage points lower among those with only compulsory education than among those with higher education at graduate level, RD = -18.4 % (95 % CI -21.4 % to -15.5 %). Educational attainment was consistently associated with influenza vaccine confidence in all seasons, among risk groups 18-64 years, and among health care workers. CONCLUSIONS: We observed an increase in confidence in influenza vaccination over the seasons examined in the study. However, the increase has not been equal in all groups and there is a clear educational gradient in influenza vaccine confidence. These findings indicate that despite efforts to increase influenza coverage over several years, the implemented measures have failed to reach all parts of the population.

Is vaccination against measles, mumps, and rubella associated with reduced rates of antibiotic treatments among children below the age of 2 years? Nationwide register-based study from Denmark, Finland, Norway, and Sweden.

OBJECTIVES: Previous studies have shown that vaccination against measles, mumps, and rubella (MMR) may have beneficial non-specific effects, reducing the risk of infections not targeted by the vaccine. We investigated if MMR vaccine given after the third dose of diphtheria-tetanus-acellular pertussis vaccine (DTaP3), was associated with reduced rates of antibiotic treatments. METHODS: Register-based cohort study following children from the age of recommended MMR vaccination until age 2 years. We included 831,287 children born in Denmark, Finland, Norway, and Sweden who had received DTaP3 but not yet MMR vaccine. Cox proportional hazards regression with age as the underlying timescale and vaccination status as a time-varying exposure was used to estimate covariate-adjusted Hazard Ratios (aHRs) and inverse probability of treatment weighted (IPTW) HRs of antibiotic treatments. Summary estimates were calculated using random-effects meta-analysis. RESULTS: Compared with only having received DTaP3, receipt of MMR vaccine after DTaP3 was associated with reduced rates of antibiotic treatments in all countries: the aHR was 0.92 (0.91-0.93) in Denmark, 0.92 (0.90-0.94) in Finland, 0.84 (0.82-0.85) in Norway, and 0.87 (0.85-0.90) in Sweden, yielding a summary estimate of 0.89 (0.85-0.93). A stronger beneficial association was seen in a negative control exposure analysis comparing children vaccinated with DTaP3 vs two doses of DTaP. CONCLUSIONS: Across the Nordic countries, receipt of MMR vaccine after DTaP3 was associated with an 11% lower rate of antibiotic treatments. The negative control analysis suggests that the findings are affected by residual confounding. Findings suggest that potential non-specific effects of MMR vaccine are of limited clinical and public health importance for the milder infections treated out-of-hospital in the Nordic setting.

Safety and effectiveness of a recombinant hepatitis E vaccine in women of childbearing age in rural Bangladesh: a phase 4, double-blind, cluster-randomised, controlled trial.

BACKGROUND: Hepatitis E virus (HEV) leads to high mortality in pregnant women in low-income countries. We aimed to evaluate the safety of a HEV vaccine and its effectiveness in preventing hepatitis E during pregnancy. METHODS: In this phase 4, double-blind, cluster-randomised trial, 67 villages in Matlab, Bangladesh, were randomised 1:1 to receive HEV239 (a recombinant HEV vaccine) or a control vaccine (Hepa-B, a hepatitis B vaccine), using block randomisation with random number tables and blocks of size eight, stratified by cluster population size. Eligible non-pregnant women (aged 16-39 years) were vaccinated intramuscularly on day 0, at 1 month, and at 6 months, and followed up for 2 years after the last immunisation. The primary endpoint was hepatitis E in the pregnant, per-protocol population (those who received all three doses within 2 days of the scheduled dates), while safety was a secondary endpoint, assessed in the intention-to-treat (ITT) population (participants who received at least one dose). Solicited adverse events were recorded for the first 7 days after each dose, and unsolicited events until 2 years after a participant's final dose. Pregnancy-related safety outcomes were assessed in the pregnant ITT population. This study is registered with ClinicalTrials.gov (NCT02759991). FINDINGS: Between Oct 2, 2017, and Feb 28, 2019, 19 460 participants were enrolled and received either HEV239 (9478 [48·7%] participants, 33 clusters) or Hepa-B (9982 [51·3%] participants, 34 clusters), of whom 17 937 (92·2%) participants received three doses and 17 613 (90·5%) were vaccinated according to protocol (8524 [48·4%] in the HEV239 group and 9089 [51·6%] in the control group). No pregnant participants were confirmed to have hepatitis E in either treatment group. HEV239 showed a mild safety profile, similar to Hepa-B, with no difference in the proportion of solicited adverse events between groups and no severe solicited events. Pain was the most common local symptom (1215 [12·8%] HEV239 recipients and 1218 [12·2%] Hepa-B recipients) and fever the most common systemic symptom (141 [1·5%] HEV239 recipients and 145 [1·5%] Hepa-B recipients). None of the serious adverse events or deaths were vaccine related. Among pregnant participants, the HEV239 group had a higher risk of miscarriage (136 [5·7%] of 2407 pregnant participants) compared with the control group (102 [3·9%] of 2604; adjusted odds ratio 1·54 [95% CI 1·15-2·08]). INTERPRETATION: The effectiveness of HEV239 in pregnant women remains uncertain. HEV239 was safe and well tolerated in non-pregnant women, but findings regarding miscarriage warrant further investigation. FUNDING: Research Council of Norway; Innovax.

Intake of trans fatty acids from partially hydrogenated vegetable and fish oils and ruminant fat in relation to cancer risk.

Intake of trans fatty acids (TFA) may influence systemic inflammation, insulin resistance and adiposity, but whether TFA intake influences cancer risk is insufficiently studied. We examined the association between TFA intake from partially hydrogenated vegetable oils (PHVO-TFA), partially hydrogenated fish oils (PHFO-TFA), and ruminant fat (rTFA) and cancer risk in the Norwegian counties study, a large cohort study with a participation rate >80%. TFA intake was assessed three times in 1974-1988 by questionnaire. A total of 77,568 men and women were followed up through 2007, during which time 12,004 cancer cases occurred. Hazard ratios (HRs) and confidence intervals (CIs) were estimated with Cox regression for cancer sites with ≥150 cases during follow-up. Significantly increased or decreased risks were found when comparing the highest and lowest intake categories (HRs, 95% CIs) for PHVO-TFA and pancreatic cancer in men (0.52, 0.31-0.87) and non-Hodgkin lymphoma (NHL) in both genders (0.70, 0.50-0.98); PHFO-TFA and rectal cancer (1.43, 1.09-1.88), prostate cancer (0.82, 0.69-0.96), and multiple myeloma (2.02, 1.24-3.28); and rTFA and all cancers (1.09, 1.02-1.16), cancer of the mouth/pharynx (1.59, 1.08-2.35), NHL (1.47, 1.06-2.04) and multiple myeloma (0.45, 0.24-0.84). Furthermore, positive trends were found for PHFO-TFA and stomach cancer (p(trend) = 0.01) and rTFA and postmenopausal breast cancer (p(trend) = 0.03). Inverse trends were found for PHVO-TFA and all cancers (p(trend) = 0.006) and cancer of the central nervous system in women (p(trend) = 0.005). PHFO-TFA, but not PHVO-TFA, seemed to increase cancer risk. The increased risks observed for rTFA may be linked to saturated fat.

Social and demographic patterns of influenza vaccination coverage in Norway, influenza seasons 2014/15 to 2020/21.

AIMS: To examine influenza vaccination coverage among risk groups (RG) and health care workers (HCW), and study social and demographic patterns of vaccination coverage over time. METHODS: Vaccination coverage was estimated by self-report in a nationally representative telephone survey among 14919 individuals aged 18-79 years over seven influenza seasons from 2014/15 to 2020/21. We explored whether belonging to an influenza RG (being >=65 years of age and/or having >=1 medical risk factor), being a HCW or educational attainment was associated with vaccination status using logistic regression. RESULTS: Vaccination coverage increased from 27 % to 66 % among individuals 65-79 years, from 13 % to 33 % among individuals 18-64 years with >=1 risk factor, and from 9 % to 51 % among HCWs during the study period. Being older, having a risk factor or being a HCW were significantly associated with higher coverage in all multivariable logistic regression analyses. Higher education was also consistently associated with higher coverage, but the difference did not reach significance in all influenza seasons. Educational attainment was not significantly associated with coverage while coverage was at its lowest (2014/15-2017/18), but as coverage increased, so did the differences. Individuals with intermediate or lower education were less likely to report vaccination than those with higher education in season 2018/19, OR = 0.61 (95 % CI 0.46-0.80) and OR = 0.58 (95 % CI 0.41-0.83), respectively, and in season 2019/20, OR = 0.69 (95 % CI 0.55-0.88) and OR = 0.71 (95 % CI 0.53-0.95), respectively. When the vaccine was funded in the COVID-19 pandemic winter of 2020/21, educational differences diminished again and were no longer significant. CONCLUSIONS: We observed widening educational differences in influenza vaccination coverage as coverage increased from 2014/15 to 2019/20. When influenza vaccination was funded in 2020/21, differences in coverage by educational attainment diminished. These findings indicate that economic barriers influence influenza vaccination decisions among risk groups in Norway.

Cohort Profile: Childhood morbidity and potential non-specific effects of the childhood vaccination programmes in the Nordic countries (NONSEnse): register-based cohort of children born 1990-2017/2018.

PURPOSE: The aim of the NONSEnse project is to investigate the non-specific effects of vaccines and immunisation programmes on the overall health of children by using information from the extensive nationwide registers on health and sociodemographic factors in Denmark, Finland, Norway and Sweden. PARTICIPANTS: The cohort covers 9 072 420 children aged 0-17 years, born 1990-2017/2018 and living in Denmark, Finland, Norway or Sweden. All countries use a unique identification number for its permanent residents, which makes it possible to link individual-level information from different registers. FINDINGS TO DATE: Data collection and harmonisation according to a common data model was completed in March 2022. As a prerequisite for comparing the effects of childhood vaccinations on the overall health of children across the Nordic countries, we have identified indicators measuring similar levels of infectious disease morbidity across these settings. So far, studies pertaining to non-specific effects of vaccines are limited to investigations that could be undertaken using aggregated data sets that were available before the NONSEnse cohort with individual-level information was completely set up. FUTURE PLANS: We are currently performing several studies of the effects on non-targeted infectious disease morbidity across the countries following vaccination against measles, mumps, rubella, diphtheria, tetanus, pertussis, human papillomavirus, rotavirus and influenza. Multiple studies are planned within the next years using different study designs to facilitate triangulation of results and enhance causal inference. REGISTRATION: No clinical trials will be conducted within the NONSEnse project.

Antibodies against Neisseria meningitidis serogroups A, C, W and Y in serum and saliva of Norwegian adolescents.

INTRODUCTION: The incidence of invasive meningococcal disease (IMD) among Norwegian 16-19-year-olds was 1-7/100,000 in the decade before the COVID-19 pandemic, with serogroup Y (MenY) dominance. In contrast to many other European countries, meningococcal vaccines are not part of the national immunisation program (NIP) in Norway. This cross-sectional study aimed to measure the degree of natural immunity against Neisseria meningitidis among adolescents in Norway to evaluate the need for introducing tetravalent meningococcal conjugate vaccine (MCV4) in the NIP. MATERIALS AND METHODS: Serum and saliva samples were collected from students in upper and lower secondary schools in Norway in 2018. Samples were analysed for meningococcal capsular polysaccharide (PS)-specific antibodies using a bead-based multiplex immunoassay. PS-specific antibody levels were linked to data on meningococcal carriage, vaccination status and risk factors for carriage (assessed with questionnaire) and analysed by linear regression of log transformed concentrations. A subset of samples from unvaccinated individuals was analysed for serum bactericidal antibodies (SBA). RESULTS: A total of 1344 participants, median age 16 years (range 12-24), were included in the study. Overall, 60.9% of the participants were female and 1137 (84.6%) were not vaccinated with MCV4. PS-specific antibody concentrations in serum and saliva were low among unvaccinated individuals for all serogroups and only 6.7-20.0% of the subpopulation with high PS-specific antibodies assessed with SBA had protective levels. Unvaccinated MenY carriers had higher levels of MenY anti-PS IgG in serum and IgA in saliva than those not carrying MenY. Use of Swedish snus was associated with lower anti-PS IgG levels in serum and waterpipe use with lower anti-PS IgG levels in saliva. CONCLUSION: Unvaccinated adolescents in Norway have a low degree of natural immunity against the serogroups of N. meningitidis predominating among cases of IMD in this age group. Therefore, introduction of MCV4 for adolescents in the NIP is recommended.

Heavy bleeding and other menstrual disturbances in young women after COVID-19 vaccination.

BACKGROUND: Many signals of menstrual disturbances as possible side effects of vaccination against COVID-19 have been reported. Our objective was to compare the risk of menstrual disturbances before and after vaccination among women aged 18-30 years in Oslo, Norway. METHODS: We used electronic questionnaires to collect reports of menstrual disturbances from 3972 women aged 18-30 years, participating in the population-based Norwegian Young Adult Cohort. We examined the occurrence of menstrual disturbances (heavier bleeding than usual, prolonged bleeding, shorter interval between menstruations, longer interval between menstruations, spot bleedings, stronger pain during menstruation, period pain without bleeding) before and after the first and second dose of COVID-19 vaccine. Relative risks (RR) according to vaccination were estimated using a self-controlled case-series design. We performed additional analyses stratified by vaccine brand, contraception/hormone use, and presence of gynecological condition(s). RESULTS: The prevalence of any menstrual disturbance was 36.7 % in the last menstrual cycle prior the first vaccine dose. The RR for heavier bleeding than usual was 1.90 (95 % CI: 1.69-2.13) after the first vaccine dose and 1.84 (95 % CI 1.66-2.03) after the second dose. Increased risks of prolonged bleeding, shorter interval between menstruations, and stronger pain during menstruation were also observed after both doses. The RRs did not differ with vaccine brand, contraception/hormone use, or presence of gynecological condition(s) for any of the menstrual disturbances. CONCLUSION: Menstrual disturbances were common regardless of vaccination. We found increased risk of menstrual disturbances after vaccination, particularly for heavier bleeding than usual, prolonged bleeding, shorter interval between menstruations, and stronger period pain. In the future, menstrual characteristics should be included in vaccine trials.