The "Let's Talk about Children" intervention in a Finnish school context: fidelity, parents' experiences, and perceived benefits.

The Let's Talk about Children intervention is a tool for parents and professionals to work together to promote children's positive development, resilience, and psychosocial well-being in social and healthcare services, at school, and in day care. The aim of this study was to evaluate the fidelity, parents' experiences, and perceived benefits of using the Let's Talk about Children intervention in a school context. Participants (N = 65 first-grader parents) completed an online questionnaire after the intervention. The results show that the intervention was delivered as designed and conducted with high fidelity. Parents' experiences of the Let's Talk about Children discussions were positive, parents felt that the atmosphere was good during the discussion, and the participants reported benefits from the intervention. Clinical trial registration:ClinicalTrials.gov, identifier NCT05038280.

Birth order and pediatric traumatic brain injury.

Pediatric traumatic brain injury (TBI) is a significant problem of public health importance worldwide. Large population-based studies on the effect of birth order on health phenomena are exceedingly rare. This study examines the relationship between birth order and risk for pediatric TBI among sibling groups. We performed a retrospective cohort study following 59,469 Finnish newborns from 1987 until age 18 years. Data on first diagnosis of TBI was recorded within the 1987 Finnish Birth Cohort (FBC). Compared with first born siblings, later born siblings had an increased risk of TBI during the follow-up period (hazard ratio [HR] 1.02; 95% confidence interval [CI] 0.91-1.14 for second born, HR 1.09; 95% CI 0.95 1.26 for third born, HR 1.28; 95% CI 1.08-1.53 for fourth or higher). When adjusted for sex and maternal age at child's birth, HRs (95% CIs) for TBI during the follow-up period were 1.12 (0.99-1.26) for second born, 1.31 (1.12-1.53) for third born and 1.61 (1.33-1.95) for fourth born or higher children, respectively. Within this large register-based population-wide study, order of birth modified risk for pediatric TBI among sibling groups. Taken together, these study findings may serve to stimulate further inquiry into genetic, psychological, or psychosocial factors which underlie differences in risk and depth of effect within and between sibling groups.

The effect of birth order on length of hospitalization for pediatric traumatic brain injury: an analysis of the 1987 Finnish birth cohort.

PURPOSE: This study examines the relationship between birth order and length of hospitalization due to pediatric traumatic brain injury (TBI). METHODS: We prospectively followed 59,469 Finnish newborns from 1987 until age 18 years. Data on first diagnosis of TBI was recorded within the 1987 Finnish Birth Cohort (FBC). Hospitalization period was divided into two categories: 2 days or less and more than 2 days. The latter was considered in this study as longer hospitalization. RESULTS: Compared with first born siblings, later born siblings had an increased risk of a longer hospitalization for TBI (12.7% of fourth or higher born birth children diagnosed with TBI were hospitalized for 2 or more days, 11.3% of first born, 10.4% of third born and 9.0% of second born). Fourth or higher born children were more likely to experience a repeat TBI; 13.4% of fourth or higher born children diagnosed with TBI had 2-3 TBIs during the study period compared to 9% of third born, 7.8% of second born and 8.8% of the first born. Injuries in the traffic environment and falls were the most common contributors to pediatric TBI and occurred most frequently in the fourth or higher birth category; 29.3% of TBIs among fourth or higher birth order were due to transport accidents and 21% were due to falls. CONCLUSIONS: This study revealed a significant increase in risk for longer hospitalization due to TBI among later born children within the same sibling group. The study provides epidemiological evidence on birth order as it relates to TBI, and its potential to help to explain some of the statistical variability in pediatric TBI hospitalization over time in this population.

Parent Support Programmes for Families Who are Immigrants: A Scoping Review.

Parental support is of paramount importance in the promotion of positive parenting, strengthening parenthood and protecting children from disadvantages due to immigration experiences. The aim was to describe what is known about parent support programmes targeted to families who are immigrants. Electronic databases and the grey literature were systematically and comprehensively searched with no time/language restrictions. JBI approach and PRISMA-ScR were used to guide the review. N = 88 articles were sourced. Interventions were targeted to improve parental practices, skills and family wellbeing, usually through group-based methods. Most interventions included components of positive parenting and family communication. Identifying the needs of the target group and cultural tailoring were reported to be highly important in gaining acceptability, promoting engagement and producing benefits. Parent support programmes for families who are immigrants potentially improve positive parental practices and families' wellbeing. There are many applicable and effective interventions to be exploited.

Predicting the stability of early employment with its timing and childhood social and health-related predictors: a mixture Markov model approach.

To extend work careers, it is important to focus on all working-aged people including young adults. The aim of this study was to identify typical patterns of work participation among young adults after their first entry into the labour market and to examine whether the timing of entry together with parental and own socio-economic position and health predict early work participation. More in-depth understanding of early careers and their early determinants is important to plan targeted interventions and to promote more stable work participation among young adults. We used the Finnish Birth Cohort 1987 including data from several registers from all 59,476 children born in 1987 as well as their parents, followed until 2015. We estimated a mixture Markov model that allowed for joint identification of latent classes of labour-market attachment, estimation of labour-market transitions within classes, and prediction of class membership using childhood social and health-related determinants. We observed that the first entry into the labour market as measured by six months in continuous employment was not a permanent entry for many, not only due to negative reasons such as unemployment and ill health but also due to more voluntary reasons such as studies. Individuals entering the labour market at a later age were more likely to be in continuous employment thereafter. More advantaged background predicted exits due to studies or - when following a late entry - stable employment, while disadvantaged background factors predicted more unstable work and long-term exits from the labour market.

Intergenerational transmission of psychiatric disorders: the 1987 Finnish Birth Cohort study.

The causes of mental disorders are multifactorial including genetic and environmental exposures, parental psychopathology being the greatest risk factor for their offspring. We set out to quantify the risk of parental psychiatric morbidity with the incidence of mental disorders among their offspring before the age of 22 years and study the sex- and age-specific associations. The present study utilises the 1987 Finnish Birth Cohort (FBC) data, which is a register-based follow-up of all 60,069 children born in Finland 1987 and followed-up until 2008. Data on psychiatric morbidity are based on inpatient care episodes of parents and both inpatient and outpatient visits of offspring and were collected from the Finnish Hospital Discharge Register which covers all Finnish citizens accessing specialized care. Altogether 7.6% of the cohort members had a parent or both parents treated at psychiatric inpatient care during the follow-up. Parental psychiatric morbidity increased the offspring's risk for psychiatric diagnoses two to threefold versus those children without parental psychiatric hospitalization, mother's morbidity comprising a greater risk than that of father's. The risk was prominent for both sexes of the offspring throughout childhood and adolescence. Psychiatric disorders possess significant intergenerational continuum. It is essential to target preventive efforts on the high-risk population that comprises families with a parent or both having mental disorders. It also implies developing appropriate social and health care interventions to support the whole family.

Association between parental hospital-treated somatic illnesses in childhood and later mental disorders among offspring up to early adulthood: An explorative study in the 1987 Finnish Birth Cohort.

Aims: Earlier studies on the associations between parental somatic illnesses and children's psychological wellbeing have focused on the most common somatic illnesses or on specific groups of illnesses. In this study, we aimed to systematically examine whether parental somatic illnesses, diagnosed during an offspring's childhood, are associated with later mental disorders of the offspring and, if so, identify which parental somatic illnesses in particular increase the likelihood for later mental disorders among the offspring. Methods: The 1987 Finnish Birth Cohort study yields longitudinal nationwide follow-up data that include a complete census of children born in a single year. Children have been followed over time through to the year 2012 using official registers maintained by the Finnish authorities. Parental diagnoses of specialised hospital inpatient care were identified from the Hospital Discharge Register after children's birth and followed up until the end of 1995. Children's psychiatric diagnoses from specialised hospital care were identified from the same register for the periods 1996/1998-2012. Logistic regression analyses were used to calculate sex-specific odds ratios for associations of mental disorders with maternal and paternal somatic illnesses using parental death, education, social assistance and psychiatric inpatient care as covariates. Results: Parental somatic illnesses during an offspring's childhood seem to increase the risk for later mental disorders. Several previously unreported somatic parental illnesses were found to be significantly associated with offspring's later mental health. Conclusions: Parental somatic illnesses should be considered as a significant adverse childhood life event, calling for preventive actions and child-centred support in adult healthcare.

Determinants of long-term unemployment in early adulthood: A Finnish birth cohort study.

Cumulative contributions of social and health-related determinants to long-term unemployment during early working life among young adults are poorly understood. Therefore, we used four cumulative indices of both parental and own social and health-related determinants of such unemployment among a cohort which comprised a complete census of children born in Finland in 1987. The cohort participants were registered in the Medical Birth Register, and they were followed-up through 2015 (N = 46 521). We calculated predicted probabilities for long-term unemployment (> 12 months) when participants were 25-28 years. Moreover, we examined whether the associations differed by unemployment at the municipal level. During the follow-up, 4.5% of women and 7.1% of men experienced long-term unemployment. All cumulative indices of parental and own social and health-related determinants predicted the probability of long-term unemployment. The greatest probabilities were observed for own social determinants, both in municipalities with high and low unemployment although the probabilities were higher in the high-unemployment municipalities. Of the individual determinants, poor school performance showed the strongest association with long-term unemployment among women (OR 6.65, 95% CI 5.21-8.55) and men (OR 3.70, 95% CI 2.96-4.67), after adjusting for other own social determinants. The results highlight the importance of life course social equality in the prevention of long-term unemployment in early adulthood.

Pathways from parental mental disorders to offspring's work disability due to depressive or anxiety disorders in early adulthood-The 1987 Finnish Birth Cohort.

BACKGROUND: Parental mental disorders have been shown to predict offspring's mental health problems. We examined whether pathways from parental mental disorders to offspring's psychiatric work disability in early adulthood are mediated through offspring's mental disorders and social disadvantage in adolescence. METHODS: Study population consisted of the 1987 Finnish Birth Cohort. Data on parents' psychiatric care or work disability due to mental diagnosis between 1987 and 2000 and the cohort participants' health and social factors between 2001 and 2005 were derived from administrative national registers. From 2006 through 2015, 52,182 cohort participants were followed for admittance of psychiatric work disability due to depressive or anxiety disorders. First, we applied a pathway analysis to examine the occurrence of each path. We then used mediation analysis to assess the proportion of association between parental mental disorders and work disability mediated by offspring's health and social disadvantage. RESULTS: The pathway model indicated that the association from parental mental disorders to offspring's work disability due to depressive or anxiety disorder is through mental disorders and social disadvantage in adolescence. Odds Ratio for the total effect of parental mental disorders on offspring's psychiatric work disability was 1.85 (95% confidence interval [CI] 1.46-2.34) in the model including offspring's mental disorders that mediated this association by 35%. Corresponding results were 1.86 (95% CI 1.47-2.35) and 28% for social disadvantage in adolescence. CONCLUSIONS: These findings suggest that intergenerational determination of work disability due to mental disorders could be addressed by actions supporting mental health and social circumstances in adolescence.

Childhood determinants for early psychiatric disability pension: A 10-year follow-up study of the 1987 Finnish Birth Cohort.

BACKGROUND: Mental disorders can affect work ability and lead to early exit from the labour market through disability pension. AIMS: This study aimed to identify childhood determinants of psychiatric disability pension in early adulthood. METHODS: The 1987 Finnish Birth Cohort includes a complete census of children born in a single year. The children were followed up from birth until 31 December 2012 using official registers maintained by the Finnish authorities. Risk factors for disability pension were examined in the full 1987 cohort (N = 58,739) and among children who had received mental health care (N = 9,599). Odds ratios were calculated for disability pension due to all mental disorders and separately for schizophrenia, depressive and anxiety and other mental and behavioural disorders in association with childhood determinants. RESULTS: Altogether, 1.4% of cohort members had retired due to mental disorders in 2003-2012. In the full 1987 cohort, female sex, parental divorce and social assistance, both mother's and father's psychiatric care and mother's psychiatric disability pension increased the risk for disability pension due to mental disorders. Among children who had received mental health care, risk factors for psychiatric disability pension were father's psychiatric care and mother's psychiatric disability pension. CONCLUSION: Childhood determinants were related to the risk of psychiatric disability pension before the age of 25. The risk factors varied by the diagnosis of the disability pension. Using knowledge of this study's risk factors should enable the identification of adolescents and young adults in general population and especially in the mental health care population who are at greatest risk of receipt of psychiatric disability pension.

Psychiatric diagnoses of children affected by their parents' traumatic brain injury: the 1987 Finnish Birth Cohort study.

OBJECTIVE: To investigate whether parental TBI increases the overall risk for psychiatric disorders and the risk for specific psychiatric diagnoses in the children affected by parental TBI. METHODS: The 1987 Finnish Birth Cohort (n = 59 476) were followed up through national registers from birth to the end of 2008. The diagnoses of cohort members and their parents were obtained from the Care Register of Health Care, provided by the National Institute of Health and Welfare. RESULTS: During the 21-year follow-up, the likelihood for psychiatric diagnoses being assessed in psychiatric care was significantly increased in males with any mental disorder (odds ratio (OR) = 1.43), substance-use-related disorders (OR = 1.71) and behavioural and emotional disorders (OR = 1.75), and in females with disorders of psychological development (OR = 1.85). CONCLUSIONS: Children affected by parental TBI are at increased risk for psychiatric disorders: males for externalizing disorders and females for developmental disorders. Observed gender interactions in the association between parental TBI and the psychiatric disorders of children warrant further study.

Parental hospital-treated somatic illnesses during offspring's childhood associated with later offspring use of psychotropic medication during childhood to young adult - The 1987 Finnish Birth Cohort study.

This study aimed to systematically examine whether parental hospital-treated somatic illnesses, diagnosed during an offspring's childhood (1987-1995), are associated with later use of psychotropic medication (1996-2012) by the offspring. If so, which parental somatic illnesses, in particular, increase the likelihood for later use of psychotropic medication among the offspring. The 1987 Finnish Birth Cohort study yields longitudinal nationwide follow-up data that include a complete census of children born in a single year. A total 58,551 offspring are included in this study and, of these 57,752 had a known father. Offspring who had used psychotropic medication between the ages of 9 and 24 years, more often had parents who had experienced a greater number of somatic illnesses when their child was aged under 9, compared to offspring without any use of psychotropic medication. The specific parental somatic illnesses early in life, for example disorders of female tract (OR 1.12, 95%CI 1.01-1.23), pregnancy with abortive outcome (1.18, 1.09-1.28), paternal acute infections (1.20, 1.05-1.38), and paternal symptoms, signs, and ill-defined conditions (1.21, 1.03-1.42), were found to be associated with psychotropic medication treatment using parental-related determinants; death, education, receipt of social assistance and psychiatric inpatient care as covariates. This suggests that these specific parental somatic illnesses can affect psychological well-being of the offspring. Preventive actions and support for the child, should be provided in situations where a parent with a somatic illness has limited ability to care for and rear their child.

Evaluation of HPV type-replacement in unvaccinated and vaccinated adolescent females-Post-hoc analysis of a community-randomized clinical trial (II).

Efficacy of human papillomavirus (HPV) vaccines promises to control HPV infections. However, HPV vaccination programs may lay bare an ecological niche for non-vaccine HPV types. We evaluated type-replacement by HPV type and vaccination strategy in a community-randomized trial executed in HPV vaccination naïve population. Thirty-three communities were randomized to gender-neutral vaccination with AS04-adjuvanted HPV16/18 vaccine (Arm A), HPV vaccination of girls and hepatitis B-virus (HBV) vaccination of boys (Arm B) and gender-neutral HBV vaccination (Arm C). Resident 1992-95 born boys (40,852) and girls (39,420) were invited. 11,662 boys and 20,513 girls were vaccinated with 20-30% and 45-48% coverage, respectively. HPV typing of 11,396 cervicovaginal samples was performed by high throughput PCR. Prevalence ratios (PR) between arms and ranked order of HPV types and odds ratio (OR) for having multiple HPV types in HPV16 or 18/45 positive individuals were calculated. The ranked order of HPV types did not significantly differ between arms or birth cohorts. For the non-HPV vaccinated 1992-1993 birth cohorts increased PR, between the gender-neutral intervention versus control arms for HPV39 (PRA 1.84, 95% CI 1.12-3.02) and HPV51 (PRA 1.56, 95% CI 1.11-2.19) were observed. In the gender-neutral arm, increased clustering between HPV39 and the vaccine-covered HPV types 16 or 18/45 (ORA16 = 5.1, ORA18/45 = 11.4) was observed in the non-HPV vaccinated 1994-1995 birth cohorts. Comparable clustering was seen between HPV51 and HPV16 or HPV18/45 (ORB16 = 4.7, ORB18/45 = 4.3), in the girls-only arm. In conclusion, definitively consistent postvaccination patterns of HPV type-replacement were not observed. Future occurrence of HPV39 and HPV51 warrant investigation.

Evaluation of Type Replacement Following HPV16/18 Vaccination: Pooled Analysis of Two Randomized Trials.

Background: Current HPV vaccines do not protect against all oncogenic HPV types. Following vaccination, type replacement may occur, especially if different HPV types competitively interact during natural infection. Because of their common route of transmission, it is difficult to assess type interactions in observational studies. Our aim was to evaluate type replacement in the setting of HPV vaccine randomized controlled trials (RCTs). Methods: Data were pooled from the Costa Rica Vaccine Trial (CVT; NCT00128661) and PATRICIA trial (NCT001226810)-two large-scale, double-blind RCTs of the HPV-16/18 AS04-adjuvanted vaccine-to compare cumulative incidence of nonprotected HPV infections across trial arms after four years. Negative rate difference estimates (rate in control minus vaccine arm) were interpreted as evidence of replacement if the associated 95% confidence interval excluded zero. All statistical tests were two-sided. Results: After applying relevant exclusion criteria, 21 596 women were included in our analysis (HPV arm = 10 750; control arm = 10 846). Incidence rates (per 1000 infection-years) were lower in the HPV arm than in the control arm for grouped nonprotected oncogenic types (rate difference = 1.6, 95% confidence interval [CI] = 0.9 to 2.3) and oncogenic/nononcogenic types (rate difference = 0.2, 95% CI = -0.3 to 0.7). Focusing on individual HPV types separately, no deleterious effect was observed. In contrast, a statistically significant protective effect (positive rate difference and 95% CI excluded zero) was observed against oncogenic HPV types 35, 52, 58, and 68/73, as well as nononcogenic types 6 and 70. Conclusion: HPV type replacement does not occur among vaccinated individuals within four years and is unlikely to occur in vaccinated populations.

Antidepressant use and violent crimes among young people: a longitudinal examination of the Finnish 1987 birth cohort.

BACKGROUND: The use of antidepressants, especially selective serotonin reuptake inhibitors (SSRIs), has been questioned due to poor efficacy and safety. We examined whether young violent offenders were more likely antidepressant users prior to their first violent offence than other young persons. METHODS: The study is a follow-up of children born in Finland in 1987 (n=59 120), linking national registers to each other using personal identity codes. Data on psychotropic drug use came from a register of reimbursed drugs and data on crimes from a register on court convictions (after the age of 14 years). Participants were followed until the age of 18 years, and for some analyses until the end of the follow-up (mean 21 years). To adjust for differences in background characteristics, regression analyses for antidepressant use were made, using the no-conviction group as the reference. RESULTS: Proportions of young people convicted by the age of 18 years were: 5% of boys (1.7% for violent crimes) and 1% (0.5%) of girls. Antidepressant use (both overall and for SSRIs) prior to violent crime was more common among those convicted than among those without convictions. Among boys with repeated violent crimes, it was also more common than among boys with non-violent crimes. Adjustment for differences in background characteristics decreased the associations between antidepressant use and violent crime, but did not eliminate them. CONCLUSIONS: The results add further evidence for caution in prescribing antidepressants among young persons. It also calls for a reanalysis of violence measures in the original trial data.

Determinants of underage induced abortion--the 1987 Finnish Birth Cohort study.

INTRODUCTION: Although underage pregnancies often end in induced abortion, data on girls who undergo termination of pregnancy are lacking. Our aim was to identify determinants of underage induced abortion and compare them with those of childbirth. MATERIAL AND METHODS: All girls born in 1987 in Finland surviving the perinatal period (n = 29 041) were included in the study and divided into three study groups: Girls undergoing induced abortion (n = 1041, 3.6%) or childbirth (n = 395, 1.4%) at <18 years of age and girls with no underage pregnancies (n = 27 605, 95.0%). RESULTS: Shared risk factors of underage induced abortion and childbirth included early onset behavioral and emotional disorders [adjusted OR 1.9 (1.4-2.5) and 2.7 (95% CI 1.8-3.9)], a history of foster care [1.5 [1.1-1.9] and 3.0 [2.3-4.1)], and socioeconomic factors, including living in a family receiving income support [1.8 (1.5-2.1) and 3.4 (2.7-4.4)], respectively. Specific risk factors of underage induced abortion were psychoactive substance use disorders [2.2 (1.3-3.5)], having a mother who smoked during pregnancy [1.5 (1.3-1.8)] or had undergone induced abortion [1.8 (1.5-2.2)]. Coping with a chronic physical illness [0.7 (0.5-0.9)], and perinatal problems [0.6 (0.4-0.7)] were inversely associated with underage induced abortion. CONCLUSIONS: The traditionally acknowledged determinants of underage childbirth played a less prominent role in induced abortion. Novel risk factors of underage induced abortion were found, including severe substance abuse and adverse maternal reproductive history, and should be addressed at all levels offering youth healthcare and social welfare services.

Mental disorder diagnoses of offspring affected by parental cancer before early adulthood: the 1987 Finnish Birth Cohort study.

OBJECTIVE: The purpose of this study is to investigate psychiatric diagnoses given to children affected by parental cancer in psychiatric and somatic specialized health care settings. METHODS: The 1987 Finnish Birth Cohort data (n = 59 476) were followed up through national registers from birth of cohort members up to the end of 2008. The health-related data of cohort members and their parents were obtained from the Care Register of Health Care provided by the National Institute of Health and Wellbeing. RESULTS: By the age of 21 years 7711 of the cohort members had used specialized psychiatric outpatient care and, of them, 549 (7.1%) were affected by parental cancer. Of affected offspring a mental disorder diagnosis was made in 424 (77.2%), while 125 (22.8%) children had not been given any specific mental disorder diagnosis. In females the likelihood for a mental disorder diagnosis assessed in outpatient care was significantly increased by up to 1.2 fold in cases of parental cancer. In males with a father having cancer, psychological development disorders were significantly increased whether assessed in outpatient (OR 1.5) or inpatient (OR1.9) settings. CONCLUSIONS: The prevalence of psychiatric diagnoses in children with parental cancer does not seem to differ from those of children with parents without cancer. However, evidence was found that children affected by parental cancer are at increased risk for some specific psychiatric disorders. Quarter of affected offspring who were referred to specialized psychiatric outpatient care only received diagnoses related to use of health care services or crises or received no psychiatric diagnosis at all. Copyright © 2016 John Wiley & Sons, Ltd.

Impact of smoking on the quantity and quality of antibodies induced by human papillomavirus type 16 and 18 AS04-adjuvanted virus-like-particle vaccine - a pilot study.

BACKGROUND: The AS04-adjuvanted bivalent L1 virus-like-particle (VLP) vaccine (Cervarix™) against infection with human papillomavirus (HPV) types 16/18 holds great promise to prevent HPV16/18 infections and associated neoplasias, but it is important to rule out significant co-factors of the neoplasias like smoking. METHODS: We conducted a pilot study to compare the quantity and quality of HPV16/18 antibody response at baseline and 7 months post vaccination in 104 non-smoking and 112 smoking female participants vaccinated at 0, 1 and 6 months with Cervarix™ (55 and 48 study participants) or with Hepatitis A vaccine (HAVRIX™) (48 and 64 participants, respectively). These 216 women were a sub-sample of 4808 baseline 16- to 17-year old Finnish women initially enrolled in the double-blind, randomized controlled phase III PATRICIA trial. Following end-of-study unblinding in 2009 they were randomly chosen out of all the participants of the three major Finnish PATRICIA study sites in the Helsinki metropolitan area (University of Helsinki, N = 535, and Family Federation Finland, N = 432) and Tampere (University of Tampere, N = 428). Following enrolment, serum samples were collected at month 0 and month 7 post 1st vaccination shot, and were analysed for levels and avidity of IgG antibodies to HPV16 and HPV18 using standard and modified (4 M urea elution) VLP ELISAs. RESULTS: We found that at month 7 post vaccination women who smoked (cotinine level > 20 ng/ml) had levels of anti-HPV16/18 antibodies comparable to those of non-smoking women. Low-avidity HPV16/18 IgG antibodies were observed in 16% of the vaccinated women, and active smoking conferred a three-fold increased risk (95% CI 1.0-9.3) of having the low-avidity antibodies. CONCLUSION: Our data suggest that while smoking does not interfere with the quantity of vaccine-induced peak IgG levels, it may affect the avidity of IgG induced by HPV16/18 vaccination.