Impact of the COVID-19 pandemic on children and adolescents: determinants and association with quality of life and mental health - A cross-sectional study

BackgroundThe medium-term impact of the COVID-19 pandemic on the wellbeing of children and adolescents remains unclear. More than two years into the pandemic, we aimed to quantify the frequency and determinants of having been severely impacted by the COVID-19 pandemic and estimate its impact on health-related quality of life (HRQoL) and mental health. MethodsData was drawn from a population-based cohort of children and adolescents, recruited between December 2021 and June 2022, in Geneva, Switzerland. We measured the impact of the pandemic via the Coronavirus impact scale, which assesses the multidimensional impact of the pandemic at the child and family level through parents report. A score higher than one standard deviation above the mean was deemed a severe impact. Parents additionally reported about their offspring HRQoL and mental health with validated scales. Determinants of having been severely impacted were assessed with logistic models, as were the associations between having experienced a severe impact and poor HRQoL or mental health. ResultsOut of 2101 participants aged 2-17, 12.7% had experienced a severe pandemic impact. Having a lasting health condition, a pandemic-related worsening of lifestyle habits or an unfavorable family environment were associated with having been severely impacted by the pandemic. Participants who had experienced a severe pandemic impact were more likely to present poor HRQoL (aOR=3.1; 95%CI: 2.3-4.4) and poor mental health (aOR=3.9; 95%CI: 2.5-6.2). ConclusionsThe COVID-19 pandemic may have persistent consequences on the wellbeing of children and adolescents, especially among those with health and family vulnerabilities.

Post-COVID syndrome prevalence and risk factors in children and adolescents: A population-based serological study

AO_SCPLOWBSTRACTC_SCPLOWO_ST_ABSObjectivesC_ST_ABSPost-COVID syndrome remain poorly studied in children and adolescents. In this study, we aimed to investigate the prevalence and risk factors of pediatric post-COVID in a population-based sample, stratifying by serological status. Study designWe used data from the SEROCoV-KIDS cohort study (State of Geneva, Switzerland), which included children (aged 6 months to 17 years) selected from random samples drawn from state registries or who had a household member participating in a COVID-19 seroprevalence study conducted by our group. Children were tested for anti-SARS-CoV-2 N antibodies. Parents filled in a questionnaire on persistent symptoms in their children (lasting over 12 weeks) compatible with post-COVID syndrome. ResultsFrom December 1st, 2021 to February 16th, 2022, 1034 children were included, among whom 570 (55.1%) were seropositive. The sex- and age-adjusted prevalence of persistent symptoms among seropositive children was 9.1% (95%CI: 6.7;11.8) and 5.0% (95%CI: 3.0;7.1) among seronegatives, with an adjusted prevalence difference ({Delta}aPrev) of 4.1% (95%CI: 1.1;7.3). After stratification by age group, the prevalence was higher among adolescents aged 12-17 years ({Delta}aPrev=8.3%, 95%CI: 3.5;13.5) than among younger children (0.0%, 95%CI: -5.2;5.2 among 6-11 years old and 4.2%; 95%CI: -4.4;13.3 among 0-5 years old). The most frequently declared persistent symptoms among seropositives were smell loss, trouble concentrating and abdominal pain. Older age, having a chronic condition and lower socioeconomic conditions were identified as risk factors. ConclusionA significant proportion of seropositive children, particularly adolescents, experienced persistent symptoms. While there is a need for further investigation, growing evidence of pediatric post-COVID syndrome urges early screening and primary care management.

Seroprevalence of anti-SARS-CoV-2 antibodies and cross-variant neutralization capacity after the Omicron BA.2 wave in Geneva, Switzerland

BackgroundMore than two years into the COVID-19 pandemic, it is generally assumed that most of the population has developed anti-SARS-CoV-2 antibodies from infection and/or vaccination. However, public health decision-making is hindered by the lack of up-to-date and precise characterization of the immune landscape in the population. We thus aimed to estimate anti-SARS-CoV-2 antibodies seroprevalence and cross-variant neutralization capacity after Omicron became dominant in Geneva, Switzerland. MethodsWe conducted a population-based serosurvey between April 29th and June 9th, 2022, recruiting children and adults of all ages from age-stratified random samples of the Geneva general population. Anti-SARS-CoV-2 antibody presence was assessed using commercial immunoassays targeting either the spike (S) or nucleocapsid (N) protein. Antibodies neutralization capacity against different SARS-CoV-2 variants was evaluated using a cell-free Spike trimer-ACE2 binding-based surrogate neutralization assay. Seroprevalence of anti-SARS-CoV-2 antibodies and neutralization capacity were estimated using Bayesian modeling frameworks accounting for the demographics, vaccination, and infection statuses of the Geneva population. ResultsAmong the 2521 individuals included in the analysis (55.2% women; 21.4% aged <18 years and 14.2% aged [≥] 65 years), overall seroprevalence of antibodies was 93.8% (95% credible interval: 93.1-94.5), including 72.4% (70.0-74.7) for infection-induced antibodies. Estimates of neutralizing antibodies based on a representative subsample of 1160 participants ranged from 79.5% (77.1-81.8) against the Alpha variant to 46.7% (43.0-50.4) against the Omicron BA.4/BA.5 subvariants. Despite having high seroprevalence of infection-induced antibodies (76.7% [69.7-83.0] for ages 0-5 years, 90.5% [86.5-94.1] for ages 6-11 years), children aged <12 years had substantially lower neutralizing activity than older participants, particularly against Omicron subvariants. In general, higher levels of neutralization activity against pre-Omicron variants were associated with vaccination, particularly having received a booster dose. Higher levels of neutralization activity against Omicron subvariants were associated with booster vaccination alongside recent infection. ConclusionMore than nine in ten individuals in the Geneva population have developed anti-SARS-CoV-2 antibodies through vaccination and/or infection, but less than half of the population has antibodies with neutralizing activity against the currently circulating Omicron BA.5 subvariant. Hybrid immunity obtained through booster vaccination and infection appears to confer the greatest neutralization capacity, including against Omicron.

Socio-economic determinants of SARS-CoV-2 infection: results from a population-based serosurvey in Geneva, Switzerland

BackgroundSARS-CoV-2 infection and its health consequences have disproportionally affected disadvantaged socio-economic groups globally. This study aimed to analyze the association between socio-economic conditions and having developed anti-SARS-CoV-2 antibodies in a population-based sample in the canton of Geneva, Switzerland. MethodsData was obtained from a population-based serosurvey of adults in Geneva and their household members, between November and December, 2020, towards the end of the second pandemic wave in the canton. Participants were tested for anti-SARS-CoV-2 antibodies. Socio-economic conditions representing different dimensions were self-reported. Mixed effects logistic regressions were conducted for each predictor to test its association with seropositive status as the main outcome. Results2,889 adults completed the study questionnaire and were included in the final analysis. Retired participants and those living in suburban areas had lower odds of a seropositive result when compared to employed participants (OR 0.42, 95% CI - 0.20 - 0.87) and those living in urban areas (OR 0.67, 95% CI - 0.46 - 0.97), respectively. People facing financial hardship for less than a year had higher odds of a seropositive result compared to those who had never faced them (OR 2.23, 95% CI - 1.01 - 4.95). Educational level, occupational position and household income were not associated with being seropositive, nor were ethnicity or country of birth. DiscussionWhile traditional measures of socio-economic position did not seem to be related to the risk of being infected in this sample, this study sheds lights on the importance of examining the broader social determinants of health when evaluating the differential impact of the pandemic within the population.

Persistent symptoms among children and adolescents with and without anti-SARS-CoV-2 antibodies: a population-based serological study in Geneva, Switzerland

AO_SCPLOWBSTRACTC_SCPLOWO_ST_ABSBackgroundC_ST_ABSIt is now established that a significant proportion of adults experience persistent symptoms after SARS-CoV-2 infection. However, evidence for children and adolescents is still inconclusive. In this population-based study, we examine the proportion of children and adolescents reporting persistent symptoms after SARS-CoV-2 infection, as assessed by serological status, and compare this to a seronegative control group. MethodsWe conducted a serosurvey in June-July 2021, recruiting 660 children and adolescents from 391 households selected randomly from the Geneva population. We tested participants for anti-SARS-CoV-2 antibodies targeting the nucleocapsid (N) protein to determine previous infection. A parent filled a questionnaire including questions on COVID-19-related symptoms lasting at least 2 weeks. FindingsAmong children seropositive for anti-SARS-CoV-2 antibodies, the sex- and age-adjusted prevalence of symptoms lasting longer than two weeks was 18.3%, compared to 11.1% among seronegative children (prevalence difference ({Delta}aPrev)=7.2%, 95%CI:1.5-13.0). Main symptoms declared among seropositive children were fatigue (11.5%) and headache (11.1%). For 8.6% (aPrev, 95%CI: 4.7-12.5) of seropositives, these symptoms were declared to be highly limiting of daily activities. Adolescents aged 12-17 years had a higher adjusted prevalence of persistent symptoms (aPrev=29.1%, 95%CI:19.4-38.7) than younger children. Comparing seropositive and seronegative adolescents, the estimated prevalence of symptoms lasting over four weeks is 4.4% ({Delta}aPrev, 95%CI:-3.8-13.6). InterpretationA significant proportion of children aged 12 to 17 years had symptoms lasting over two weeks after SARS-CoV-2 infection, with an estimated prevalence of symptoms lasting over 4 weeks of 4.4% in this age group. This represents a large number of adolescents in absolute terms, and should raise concern in the context of unknown long-term evolution of symptoms. Younger children appear to experience long-lasting symptoms less frequently, as no difference was observed between the seropositive and seronegative sample. Further studies with larger samples sizes are needed. FundingSwiss Federal Office of Public Health, Geneva General Directorate of Health, HUG Private Foundation, SSPH+, Fondation des Grangettes.

Epidemiological, virological and serological investigation into a SARS-CoV-2 outbreak (Alpha variant) in a primary school in Geneva, Switzerland: a prospective longitudinal study

We report a prospective epidemiological, virological and serological investigation of a SARS-CoV-2 outbreak in a primary school, as part of a longitudinal, prospective, primary school-based surveillance study. It involved repeated testing of pupils and teachers and household members of participants who tested positive, with rapid antigen tests and/or RT-PCR (Day 0-2 and Day 5-7), serologies on dried capillary blood samples (Day 0-2 and Day 30), contact tracing interviews and SARS-CoV-2 whole genome sequencing. This SARS-CoV-2 outbreak caused by the Alpha variant involved 20 children aged 4 to 6 years from 4 classes, 2 teachers and a total of 4 household members. Infection attack rates were between 11.8 and 62.0% among pupils from the 4 classes, 22.2% among teachers and 0% among non-teaching staff. Secondary attack rate among household members was 15.4%. Symptoms were reported by 63% of infected children, 100% of teachers and 50% of household members. All analysed sequences but one showed 100% identity. Serological tests detected 8 seroconversions unidentified by SARS-CoV-2 virological tests. This study confirmed child-to-child and child-to-adult transmission of the infection. Effective measures to limit transmission in schools have the potential to reduce the overall community circulation.

Seroprevalence of anti-SARS-CoV-2 antibodies six months into the vaccination campaign in Geneva, Switzerland

BackgroundUp-to-date seroprevalence estimates are critical to describe the SARS-CoV-2 immune landscape in the population and guide public health measures. We aimed to estimate the seroprevalence of anti-SARS-CoV-2 antibodies 15 months into the COVID-19 pandemic and six months into the vaccination campaign. MethodsWe conducted a population-based cross-sectional serosurvey between June 1 and July 7, 2021, recruiting participants from age- and sex-stratified random samples of the general population. We tested participants for anti-SARS-CoV-2 antibodies targeting the spike (S) or nucleocapsid (N) proteins (Roche Elecsys immunoassays). We estimated the anti-SARS-CoV-2 antibodies seroprevalence following vaccination and/or infection (anti-S antibodies), or infection only (anti-N antibodies). ResultsWe included 3355 individuals, of which 1814 (54.1%) were women, 697 (20.8%) were aged <18 years and 449 (13.4%) were aged [≥]65 years, 2161 (64.4%) tested positive for anti-S antibodies, and 906 (27.0%) tested positive for anti-N antibodies. The total seroprevalence of anti-SARS-CoV-2 antibodies was 66.1% (95% credible interval, 64.1-68.0). We estimated that 29.9% (28.0-31.9) of the population developed antibodies after infection; the rest having developed antibodies only via vaccination. Seroprevalence estimates were similar across sexes, but differed markedly across age groups, being lowest among children aged 0-5 years (20.8% [15.5-26.7]) and highest among older adults aged [≥]75 years (93.1% [89.6-96.0]). Seroprevalence of antibodies developed via infection and/or vaccination was higher among participants with a higher educational level. ConclusionsMost adults have developed anti-SARS-CoV-2 antibodies, while most teenagers and children remain vulnerable to infection. As the SARS-CoV-2 Delta variant spreads and vaccination rates stagnate, efforts are needed to address vaccine hesitancy, particularly among younger individuals and socioeconomically disadvantaged groups, and to minimize spread among children.

Applying mixture model methods to SARS-CoV-2 serosurvey data from the SEROCoV-POP study

Serosurveys are an important tool to estimate the true extent of the current SARS-CoV-2 pandemic. So far, most serosurvey data have been analysed with cut-off based methods, which dichotomize individual measurements into sero-positives or negatives based on a predefined cutoff. However, mixture model methods can gain additional information from the same serosurvey data. Such methods refrain from dichotomizing individual values and instead use the full distribution of the serological measurements from pre-pandemic and COVID-19 controls to estimate the cumulative incidence. This study presents an application of mixture model methods to SARS-CoV-2 serosurvey data from the SEROCoV-POP study from April and May 2020 in Geneva (2766 individuals). Besides estimating the total cumulative incidence in these data (8.1% (95% CI: 6.8% - 9.8%)), we applied extended mixture model methods to estimate an indirect indicator of disease severity, which is the fraction of cases with a distribution of antibody levels similar to hospitalised COVID-19 patients. This fraction is 51.2% (95% CI: 15.2% - 79.5%) across the full serosurvey, but differs between three age classes: 21.4% (95% CI: 0% - 59.6%) for individuals between 5 and 40 years old, 60.2% (95% CI: 21.5% - 100%) for individuals between 41 and 65 years old and 100% (95% CI: 20.1% - 100%) for individuals between 66 and 90 years old. Additionally, we find a mismatch between the inferred negative distribution of the serosurvey and the validation data of pre-pandemic controls. Overall, this study illustrates that mixture model methods can provide additional insights from serosurvey data.

COVID-19 Vaccination acceptance in the canton of Geneva: A Cross-Sectional Population-Based Study

ObjectiveThis study aimed to assess acceptance of COVID-19 vaccination as well as its sociodemographic and clinical determinants in a general population sample three months after the launch of the vaccination program in Switzerland. MethodsIn March 2021, an online questionnaire on vaccination acceptance was proposed to adults included in a longitudinal cohort study of previous population-based serosurveys carried out in the canton of Geneva. Questions were asked about COVID-19 vaccination acceptance, reasons of acceptance or refusal, and attitudes about vaccination in general. Data on demographic (age, sex, education, income, professional status, living conditions) and health-related characteristics (having a chronic disease, COVID-19 diagnosis, smoking status) were assessed at inclusion in the cohort (December 2020). ResultsOverall, 4067 participants (completion rate of 77.4%) responded to the survey between March 17 and April 1, 2021. The mean age of respondents was 53.3 years and 56.0% were women. Most had completed tertiary education (64.7%) and over 60% were currently professionally active. At the time of the survey, 17.2% of respondents had already been vaccinated with at least one dose or had made an appointment to get vaccinated, and an additional 58.5% intended or rather intended to get vaccinated. The overall acceptance of COVID-19 vaccination was 75.7%, with a higher acceptance among men compared to women, older adults compared to younger adults, high-income individuals compared to those with a low income, participants living in urban and semi-urban areas compared to rural, and retirees and students compared to employed individuals. Acceptance was lower among individuals having completed apprenticeships and secondary education compared to those with tertiary education. The most common reasons reported by participants intending to get vaccinated were the desire to get back to normal, to protect themselves, their community and/or society, and their relatives or friends against the risk of infection by SARS-CoV-2, as well as the desire to travel. Less than half (45.6%) of participants having children were willing or rather willing to have their children vaccinated against COVID-19 if it were recommended by public health authorities. ConclusionAlthough our study found a 75.7% acceptance of COVID-19 vaccination, there were noticeable socio-demographic disparities in vaccination acceptance. These data will be useful for public health measures targeting hesitant populations when developing health communication strategies. These results will be updated over time with a new release of the survey in autumn 2021.

Seroprevalence of anti-SARS-CoV-2 IgG antibodies, risk factors for infection and associated symptoms in Geneva, Switzerland: a population-based study

BackgroundPopulation-based serological surveys provide a means for assessing the immunologic landscape of a community, without the biases related to health-seeking behaviors and testing practices typically associated with rt-PCR testing. This study assesses SARS-CoV-2 seroprevalence over the first epidemic wave in Canton Geneva, Switzerland, as well as biological and socio-economic risk factors for infection and symptoms associated with IgG seropositivity. Methods and findingsBetween April 6 and June 30, 2020, former participants of a yearly representative cross-sectional survey of the 20-75-year-old population of the canton of Geneva were invited to participate in a seroprevalence study, along with household members five years and older. We collected blood and tested it for anti-SARS-CoV-2 immunoglobulins G (IgG). Questionnaires were self-administered. We estimated seroprevalence with a Bayesian model accounting for test performance and sampling design. We included 8344 participants (53.5% women, mean age 46.9 years). The population-level seroprevalence over the 12-week study period was 7.8 % (95% Credible Interval (CrI) 6.8-8.9), accounting for sex, age and household random effects. Seroprevalence was highest among 18-49 year olds (9.5%, 95%CrI 8.1-10.9), with young children (5-9 years) and those >65 years having significantly lower seroprevalence (4.3% and 4.7-5.4% respectively). Men were more likely to be seropositive than women (relative risk 1.2, 95%CrI 1.1-1.4). Odds of seropositivity were reduced for female retirees (0.46, 95%CI 0.23-0.93) and unemployed men (0.35, 95%CI 0.13-1.0) compared to employed individuals, and for current smokers (0.36, 95%CI 0.23-0.55) compared to never-smokers. We found no significant association between occupation, level of education, neighborhood income and the risk of being seropositive. Symptoms most strongly associated with seropositivity were anosmia/dysgeusia, loss of appetite, fever, fatigue and myalgia and/or arthralgia. Thirteen percent of seropositive participants reported no symptoms. ConclusionsOur results confirm a low population seroprevalence of anti-SARS-CoV-2 antibodies after the first wave in Geneva, a region hard hit by the COVID-19 pandemic. Socioeconomic factors were not associated with seropositivity in this sample. The elderly and young children were less frequently seropositive, though it is not clear how biology and behaviors shape these differences. These specificities should be considered when assessing the need for targeted public health measures.