Post-vaccination infection rates and modification of COVID-19 symptoms in vaccinated UK school-aged children and adolescents: A prospective longitudinal cohort study

Understanding global research trends in the control and prevention of infectious diseases for children: Insights from text mining and topic modeling

INTRODUCTION

The emergence of novel infectious diseases has amplified the urgent need for effective prevention strategies, especially ones targeting vulnerable populations such as children. Factors such as the high incidence of both emerging and existing infectious diseases, delays in vaccinations, and routine exposure in communal settings heighten children's susceptibility to infections. Despite this pressing need, a comprehensive exploration of research trends in this domain remains lacking. This study aims to address this gap by employing text mining and modeling techniques to conduct a comprehensive analysis of the existing literature, thereby identifying emerging research trends in infectious disease prevention among children.

METHODS

A cross-sectional text mining approach was adopted, focusing on journal articles published between January 1, 2003, and August 31, 2022. These articles, related to infectious disease prevention in children, were sourced from databases such as PubMed, CINAHL, MEDLINE (Ovid), Scopus, and Korean RISS. The data underwent preprocessing using the Natural Language Toolkit (NLTK) in Python, with a semantic network analysis and topic modeling conducted using R software.

RESULTS

The final dataset comprised 509 journal articles extracted from multiple databases. The study began with a word frequency analysis to pinpoint relevant themes, subsequently visualized through a word cloud. Dominant terms encompassed "vaccination," "adolescent," "infant," "parent," "family," "school," "country," "household," "community," "HIV," "HPV," "COVID-19," "influenza," and "diarrhea." The semantic analysis identified "age" as a key term across infection, control, and intervention discussions. Notably, the relationship between "hand" and "handwashing" was prominent, especially in educational contexts linked with "school" and "absence." Latent Dirichlet Allocation (LDA) topic modeling further delineated seven topics related to infectious disease prevention for children, encompassing (1) educational programs, (2) vaccination efforts, (3) family-level responses, (4) care for immunocompromised individuals, (5) country-specific responses, (6) school-based strategies, and (7) persistent threats from established infectious diseases.

CONCLUSION

The study emphasizes the indispensable role of personalized interventions tailored for various child demographics, highlighting the pivotal contributions of both parental guidance and school participation.

CLINICAL RELEVANCE

The study provides insights into the complex public health challenges associated with preventing and managing infectious diseases in children. The insights derived could inform the formulation of evidence-based public health policies, steering practical interventions and fostering interdisciplinary synergy for holistic prevention strategies.

COVID-19 vaccination hesitancy among Italian parents: A systematic review and meta-analysis

In May 2021, the Italian government extended the COVID-19 vaccination campaign to 12- to 18-year-old subjects and, starting December 2021, vaccines were also offered to children between 5 and 11 years-old. Despite these efforts, suboptimal vaccination coverages are reported. The purpose of this review is to estimate the proportion of parents/caregivers of children and adolescents expressing COVID-19 vaccine hesitancy in Italy. The vaccine hesitation rate among parents of minors was 55.1% (95%CI: 43.8-66.1%). A higher value was evidenced in studies focusing on children (59.9%; 95%CI = 43.7-75.1%) compared to the ones focusing on adolescents (51.3%; 95%CI = 34.5-68.0%). The main reasons for unwillingness were the belief that the vaccine was unsafe or ineffective, fear of adverse events, and considering COVID-19 a non-threatening disease. The implementation of effective communication campaigns and health educational programs on safe pediatric vaccinations is essential to support strategies to bolster vaccination confidence.

Effectiveness of the BNT162b2 vaccine in preventing morbidity and mortality associated with COVID-19 in children aged 5 to 11 years: A systematic review and meta-analysis

A rapid systematic review, based on Cochrane rapid review methodology was conducted to assess the effectiveness of two 10μg doses of BNT162b2 vaccine in preventing morbidity and mortality associated with COVID-19 in children aged 5 to 11 years. We searched the Cochrane Library COVID-19 study register, the COVID-NMA living review database and the McMaster University Living Evidence Synthesis for pre-appraised trials and observational studies up to 7 December 2022. Records were screened independently in duplicate. Where appraisal was not available, these were done in duplicate. Meta-analysis was conducted using RevMan 5.3 presenting risk ratios/odds ratios/inverse vaccine efficacy with 95% confidence intervals (CI). GRADE for assessing the overall certainty of the evidence was done in Gradepro. We screened 403 records and assessed 52 full-text articles for eligibility. One randomised controlled trial (RCT) and 24 observational studies were included. The RCT reported that BNT162b2 was likely safe and 91% efficacious, RR 0.09 (95% CI 0.03 to 0.32) against incident COVID-19 infection (moderate certainty evidence). In absolute terms, this is 19 fewer cases per 1,000 vaccines delivered (ranging from 15 to 21 fewer cases). Observational studies reported vaccine effectiveness (VE) against incident COVID-19 infection of 65% (OR 0.35, 95% CI 0.26 to 0.47) and 76% against hospitalisation (OR 0.24, 95% CI 0.13 to 0.42) (moderate certainty evidence). The absolute effect is 167 fewer cases per 1,000 vaccines given (ranging from 130 fewer to 196 fewer cases) and 4 fewer hospitalisations per 10,000 children (from 3 fewer to 5 fewer hospitalisations). Adverse events following vaccination with BNT162b2 were mild or moderate and transient. The evidence demonstrated a reduction in incident COVID-19 cases and small absolute reduction in hospitalisation if a two-dose BNT162b2 vaccine regimen is offered to children aged 5 to 11 years, compared to placebo. PROSPERO registration: CRD42021286710.

Assessment of the detection accuracy of SARS-CoV-2 rapid antigen test in children and adolescents: An updated meta-analysis

BACKGROUND

Real-time and appropriate antigen tests play a pivotal role in preventing severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, a previous meta-analysis reported that the antigen test had lower sensitivity for the detection of SARS-CoV-2 in children. To provide a comprehensive evaluation of diagnostic efficiency, we performed an updated meta-analysis to assess the detection accuracy of SARS-CoV-2 antigen tests stratified by days after symptom onset and specimen type in children and adolescents.

METHODS

We comprehensively searched for appropriate studies in the PubMed, Embase, and Cochrane Library databases. Studies on the diagnostic accuracy of antigen tests for SARS-CoV-2 in children and adolescents were included. The relevant data of the included studies were extracted to construct a 2 × 2 table on a per-patient basis. The overall sensitivity and specificity of the SARS-CoV-2 antigen tests were estimated using a bivariate random-effects model.

RESULTS

Seventeen studies enrolling 10 912 patients were included in the present meta-analysis. For the detection accuracy of SARS-CoV-2 antigen tests, the meta-analysis generated a pooled sensitivity of 77.9% (95% confidence interval [CI]: 67.3%-85.8%) and a pooled specificity of 99.6% (95% CI: 98.9%-99.8%). The subgroup analysis of studies that examined antigen tests in symptomatic participants ≦7 days after symptom onset generated a pooled sensitivity of 79.4% (95% CI: 47.6%-94.2%) and a pooled specificity of 99.4% (95% CI: 98.2%-99.8%). Another subgroup analysis of studies that evaluated nasal swab specimens demonstrated a pooled sensitivity of 80.1% (95% CI: 65.0%-89.7%) and a pooled specificity of 98.5% (95% CI: 97.3%-9.2%).

CONCLUSION

Our findings demonstrated that the antigen test performed using nasal swab specimens exhibited high sensitivity for the detection of SARS-CoV-2 within 7 days after symptom onset. Therefore, antigen testing using nasal swabs may be effective in blocking SARS-CoV-2 transmission in children.

Anti-SARS-CoV-2 vaccination in adolescent and adult patients with juvenile-onset systemic lupus erythematosus: tolerability and impact on disease activity

OBJECTIVES

JSLE has a severe presentation and a remitting course. Patients with JSLE carry an increased vulnerability to infections, which also act as triggers of disease flare. Thus, vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an important tool in JSLE. The objective of this study is to evaluate the tolerability and the safety of anti-SARS-CoV-2 vaccination, including the booster, in a monocentric cohort of JSLE patients.

METHODS

Clinical records of JSLE patients who received at least one dose of any anti-SARS-CoV-2 vaccine were retrospectively reviewed. Data about disease activity, treatment, anti-SARS-CoV-2 vaccination and COVID-19 infection were collected.

RESULTS

Sixty-five JSLE patients received at least one dose of anti-SARS-CoV-2 vaccination, while 46 patients completed the schedule with the booster. The rate of mild-moderate adverse events was 66%, mainly comprising fever, fatigue, arthromyalgias and pain at injection site. The rate of adverse events after the booster was similar to that registered after the first two doses. No significant changes after SARS-CoV-2 vaccination in BILAG and SLEDAI were observed. Disease flare rate (mainly LN) after immunization was 10.8%. Flares occurred predominantly in patients with moderate disease activity before immunization; accordingly, SLEDAI ≥4 identified patients at risk of flare while Lupus Low Disease Activity State (LLDAS) plays a protective role against post-vaccination flare.

CONCLUSIONS

This study confirms that anti-SARS-CoV-2 vaccination in JSLE is well tolerated; a strict clinical monitoring and a thoughtful choice of vaccination timing should be devoted to patients not in LLDAS due to the risk of post-vaccine flare.

Factors associated with the formation of SARS-CoV-2 case-clusters in Danish schools: a nationwide register-based observational study

A register-based retrospective observational study was conducted to describe SARS-CoV-2 cases and case-clusters in schoolchildren of Danish primary and lower secondary schools and identify which factors were associated with the occurrence of case-clusters in schools. The study period was the autumn school semester 2021. Clusters were defined as three or more cases in a school-class level within 14 days. Descriptive analysis was carried out and multivariable logistic regression analysis was performed to determine which factors were associated with case introductions (i.e., primary case) being linked to a cluster. More cases and clusters were identified in lower than in higher class levels. Out of 21,497 cases introduced into a school, 41.6% started a cluster. A higher assumed immunity level in a class level was significantly reducing the odds of a case introduction being linked to a cluster (e.g., assumed immunity of ≥80% vs <20%: OR: 0.28; 95%CI: 0.17-0.44). A previous infection (in the primary case) had a protective effect (OR: 0.58; 95%CI: 0.33-0.99). This study suggests that most cases appearing in schools did not induce clusters, but that once cluster occur sizes can be large. It further indicates that vaccination of children markedly reduces the risk of secondary infections.

A Methodological Framework for Assessing the Benefit of SARS-CoV-2 Vaccination following Previous Infection: Case Study of Five- to Eleven-Year-Olds

Vaccination rates against SARS-CoV-2 in children aged five to eleven years remain low in many countries. The current benefit of vaccination in this age group has been questioned given that the large majority of children have now experienced at least one SARS-CoV-2 infection. However, protection from infection, vaccination or both wanes over time. National decisions on offering vaccines to this age group have tended to be made without considering time since infection. There is an urgent need to evaluate the additional benefits of vaccination in previously infected children and under what circumstances those benefits accrue. We present a novel methodological framework for estimating the potential benefits of COVID-19 vaccination in previously infected children aged five to eleven, accounting for waning. We apply this framework to the UK context and for two adverse outcomes: hospitalisation related to SARS-CoV-2 infection and Long Covid. We show that the most important drivers of benefit are: the degree of protection provided by previous infection; the protection provided by vaccination; the time since previous infection; and future attack rates. Vaccination can be very beneficial for previously infected children if future attack rates are high and several months have elapsed since the previous major wave in this group. Benefits are generally larger for Long Covid than hospitalisation, because Long Covid is both more common than hospitalisation and previous infection offers less protection against it. Our framework provides a structure for policy makers to explore the additional benefit of vaccination across a range of adverse outcomes and different parameter assumptions. It can be easily updated as new evidence emerges.

A snapshot of pediatric inpatients and outpatients with COVID-19: a point prevalence study from Turkey

This multi-center point prevalence study evaluated children who were diagnosed as having coronavirus disease 2019 (COVID-19). On February 2nd, 2022, inpatients and outpatients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were included in the study from 12 cities and 24 centers in Turkey. Of 8605 patients on February 2nd, 2022, in participating centers, 706 (8.2%) had COVID-19. The median age of the 706 patients was 92.50 months, 53.4% were female, and 76.7% were inpatients. The three most common symptoms of the patients with COVID-19 were fever (56.6%), cough (41.3%), and fatigue (27.5%). The three most common underlying chronic diseases (UCDs) were asthma (3.4%), neurologic disorders (3.3%), and obesity (2.6%). The SARS-CoV-2-related pneumoniae rate was 10.7%. The COVID-19 vaccination rate was 12.5% in all patients. Among patients aged over 12 years with access to the vaccine given by the Republic of Turkey Ministry of Health, the vaccination rate was 38.7%. Patients with UCDs presented with dyspnea and pneumoniae more frequently than those without UCDs (p < 0.001 for both). The rates of fever, diarrhea, and pneumoniae were higher in patients without COVID-19 vaccinations (p = 0.001, p = 0.012, and p = 0.027).  Conclusion: To lessen the effects of the disease, all eligible children should receive the COVID-19 vaccine. The illness may specifically endanger children with UCDs. What is Known: • Children with COVID-19 mainly present with fever and cough, as in adults. • COVID-19 may specifically threaten children with underlying chronic diseases. What is New: • Children with obesity have a higher vaccination rate against COVID-19 than children without obesity. • Among unvaccinated children, fever and pneumoniae might be seen at a higher ratio than among vaccinated children.

Parental COVID-19 Vaccine Hesitancy for Children and Its Influencing Factors: A Riyadh-Based Cross-Sectional Study

It is well known that vaccination is the best clinical approach for successfully controlling COVID-19 infection. Understanding the disparities in COVID-19 vaccination apprehension among parents in different societies is crucial for effectively implementing COVID-19 vaccination programs. This observational cross-sectional study was carried out in the Riyadh region of Saudi Arabia between February and April 2022. The validated questionnaire was shared with parents who had children between the ages of five and eleven years. The collected data were analyzed using descriptive and inferential statistical methods. Multinomial regression analysis was conducted to determine the factors significantly affecting vaccine-use decisions. Of the 699 participants, 83% of the mothers were between the ages of 35 and 44 years, 67% were university educated, and only 14% were healthcare workers. A large proportion of parents, with an age range of 18–34 years (p = 0.001), and those with a higher income group (p = 0.014), demonstrated significant vaccine hesitancy. Further, parents who received one or two vaccination doses were significantly (p = 0.02) more hesitant than those who received more than two doses of the vaccine. Furthermore, a significantly (p = 0.002) high percentage of parents who follow the Ministry of Health (MOH) guidelines for personal preventive measures were hesitant about their children’s vaccination. Concerns about side effects (31.4%) and a lack of safety data (31.2%) on the COVID-19 vaccines were the two most significant reasons for parents to develop vaccine hesitancy. Social media (24.3%), poor perceived immunity (16.3 %), and news articles (15.5%) were the top three contributors to this hesitancy. Vaccinated parents were 8.21 times more likely to be vaccination-hesitant than non-vaccinated parents. Additionally, parents with less education and a COVID-19-positive child at home increased the odds of vaccine hesitancy by 1.66 and 1.48 times, respectively. Overall, one-third of the parents were not prepared to vaccinate their children, and one-quarter of the respondents had not decided about vaccination. This study shows that parents in Riyadh are generally reluctant to vaccinate their children against COVID-19. As social media is a primary source of information for parents, public health professionals should utilize the platform to encourage parents to support vaccine acceptance.

210-Day Kinetics of Total, IgG, and Neutralizing Spike Antibodies across a Course of 3 Doses of BNT162b2 mRNA Vaccine

Introduction: We tested the total spike antibody (S-Ab), IgG/IgM S-Ab, and neutralizing antibody (N-Ab) responses of COVID-19-naïve subjects from before their first BNT162b2 vaccination up to 210 days after boosting. Methods: We studied 136 COVID-19-naïve subjects who received three doses of the Pfizer mRNA vaccine (39 males, 97 females, mean age 43.8 ± 13.5 years) from January 2021 to May 2022. Serum was assessed for total S-Ab (Roche), IgG/M (Abbott), and N-Ab (Snibe). Results: Peak antibody levels were measured 20-30 days after each dose, with booster dosing eliciting significantly higher peak antibodies than the second dose: total S-Ab 2219 vs. 19,551 BAU/mL (difference 16,667 BAU/mL, p < 0.0001); IgG 2270 vs. 2932 BAU/mL (difference 660 BAU/mL, p = 0.04); and N-Ab 3.52 vs. 26.4 µg/mL (difference 21.4 µg/mL, p < 0.0001). Only IgM showed a lower peak post-booster antibody titer (COI 2.11 vs. 0.23, difference 1.63, 95% CI 1.05 to 2.38, p < 0.0001). By 180−210 days after the second or third vaccination, total S-Ab/IgG/N-Ab had decreased by 68.7/93.8/73.6% vs. 82.8/86.3/79.5%. The half-lives of IgG and N-Ab antibodies were longer after the third vaccination (IgG: 65 vs. 34 days, N-Ab: 99 vs. 78 days). Conclusion: Total S-Ab/IgG/N-Ab showed a greater increase post-booster, with IgG/N-Ab having a longer half-life.

COVID-19 Vaccine Effectiveness against Omicron Variant among Underage Subjects: The Veneto Region's Experience

Even if most of the complications due to COVID-19 are observed in the elderly, in Italy the impact of COVID-19 among young people has not been negligible. Furthermore, their contribution to SARS-CoV-2 circulation is still unclear. These reasons have driven policy makers to involve subjects aged 5 to 17 years in the COVID-19 vaccination campaign. However, the trade-off of vaccinating this age-group should be further investigated, especially in view of the rise of new immunologically evasive variants of concern (VOCs). We used regional databases to retrospectively estimate vaccine effectiveness over time of each approved vaccination schedule among children (5–11) and adolescents (12–17). Our findings suggest that COVID-19 vaccines were highly effective and their protection levels lasted longer during a period of Delta variant predominance, whereas they offered just mild to moderate levels of protection—apparently affected by a rapid waning effect—in a period of Omicron variant predominance. Considering these results, it is plausible to evaluate a reformulation of possible future COVID-19 vaccination campaigns among underage subjects. However, effectiveness against serious complications due to COVID-19, as well as indirect benefits of underage vaccinations, should first be addressed. Furthermore, vaccine effectiveness should be kept monitored, as new VOCs may arise, but also new adapted vaccines may start being administered.