Herd immunity and vaccination of children for COVID-19

Immunogenicity and Safety of SARS-CoV-2 Protein Subunit Recombinant Vaccine (IndoVac®) as a Heterologous Booster Dose against COVID-19 in Indonesian Adolescents

Adolescents are vulnerable to Coronavirus disease 2019 (COVID-19) infections; thus, their antibodies should be maintained above the protective value. This study aimed to evaluate the immune response and safety to the SARS-CoV-2 protein subunit recombinant vaccine (IndoVac®) as a heterologous booster dose against COVID-19 in Indonesian adolescents. This open-label prospective intervention study enrolled 150 clinically healthy adolescents aged 12-17 years who had received complete primary doses of the CoronaVac® vaccine from Garuda Primary Care Centres in Bandung City. The result of immunogenicity was presented with a 95% confidence interval (CI) and analyzed with t-tests from 14 days and 3, 6, and 12 months. The neutralizing antibody geometric mean titers (GMTs) (IU/mL) at baseline and 14 days after booster dose were 303.26 and 2661.2, respectively. The geometric mean fold rises (GMFR) at 3, 6, and 12 months after booster dose were 6.67 (5.217-8.536), 3.87 (3.068-4.886), and 2.87 (2.232-3.685), respectively. Both the neutralizing antibody and IgG antibody were markedly higher in the adolescents than in the adults at every timepoint. The incidence rate of adverse effects (AEs) until 28 days after booster dose was 82.7%, with a higher number of local events reported. Most reported solicited AEs were local pain followed by myalgia with mild intensity. Unsolicited AEs varied with each of the incidence rates < 10%, mostly with mild intensity. Adverse events of special interest (AESI) were not observed. At the 12-month follow-up after the booster dose, four serious adverse events (SAEs) not related to investigational products and research procedures were noted. This study showed that IndoVac® has a favorable immunogenicity and safety profile as a booster in adolescents and that the antibody titer decreases over time.

Advancing the treatment of anxiety disorders in transition-age youth: a review of the therapeutic effects of unconscious exposure

BACKGROUND

The real-world effectiveness of exposure-based therapies for youth depends on the willingness and ability of young people to tolerate confronting their fears, which can be experienced as highly aversive and create problems with treatment engagement and acceptance. Recently, neuroscientific research on the nonconscious basis of fear has been translated into novel exposure interventions that bypass conscious processing of feared stimuli and that thus do not cause phobic youth to experience distress. We present a review of these unconscious exposure interventions.

METHODS

A PRISMA-based search yielded 20 controlled experiments based on three paradigms that tested if fear-related responses could be reduced without conscious awareness in highly phobic, transition-age youth: 14 randomized controlled trials (RCTs), 5 fMRI studies (1 was also an RCT), 4 psychophysiological studies (3 were also RCTs), and 1 ERP study. We conducted meta-analyses of outcomes where feasible.

RESULTS

Unconscious exposure interventions significantly (1) reduced avoidance behavior (range of Cohen's d = 0.51-0.95) and self-reported fear (d = 0.45-1.25) during in vivo exposure to the feared situation; (2) reduced neurobiological indicators of fear (d = 0.54-0.62) and concomitant physiological arousal (d = 0.55-0.64); (3) activated neural systems supporting fear regulation more strongly than visible exposure to the same stimuli (d = 1.2-1.5); (4) activated regions supporting fear regulation that mediated the reduction of avoidance behavior (d = 0.70); (5) evoked ERPs suggesting encoding of extinction memories (d = 2.13); and (6) had these effects without inducing autonomic arousal or subjective fear.

CONCLUSIONS

Unconscious exposure interventions significantly reduce a variety of symptomatic behaviors with mostly moderate effect sizes in transition-age youth with specific phobias. fMRI and physiological findings establish a neurophysiological basis for this efficacy, and suggest it occurs through extinction learning. Unconscious exposure was well tolerated, entirely unassociated with drop out, and is highly scalable for clinical practice. However, a number of limitations must be addressed to assess potential clinical impacts, including combining unconscious exposure with exposure therapy to boost treatment acceptance and efficacy.

Pneumococcal Vaccination Strategies in 50-Year-Olds to Decrease Racial Disparities: A US Societal Perspective Cost-Effectiveness Analysis

OBJECTIVES

This study assesses the impact of expanding pneumococcal vaccination to all 50-year-olds to decrease racial disparities by estimating from the societal perspective, the cost-effectiveness of 20-valent pneumococcal conjugate vaccine (PCV20) and 15-valent conjugate vaccine followed by 23-valent polysaccharide vaccine (PCV15/PPSV23) for 50-year-olds.

METHODS

A Markov model compared the cost-effectiveness of PCV20 or PCV15/PPSV23 in all general population 50- and 65-years-olds compared with current US recommendations and with no vaccination in US Black and non-Black cohorts. US data informed model parameters. Pneumococcal disease societal costs were estimated using direct and indirect costs of acute illness and of pneumococcal-related long-term disability and mortality. Hypothetical 50-year-old cohorts were followed over their lifetimes with costs and effectiveness discounted 3% per year. Deterministic and probabilistic sensitivity analyses assessed model uncertainty.

RESULTS

In Black cohorts, PCV20 for all at ages 50 and 65 was the least costly strategy and had greater effectiveness than no vaccination and current recommendation strategies, whereas PCV15/PPSV23 at 50 and 65 cost more than $1 million per quality-adjusted life year (QALY) gained compared with PCV20 at 50 and 65. In non-Black cohorts, PCV20 at 50 and 65 cost $62 083/QALY and PCV15/PPSV23 at 50 and 65 cost more than $1 million/QALY with current recommendations, again being more costly and less effective. In probabilistic sensitivity analyses, PCV20 at 50 and 65 was favored in 85.7% (Black) and 61.8% (non-Black) of model iterations at a $100 000/QALY gained willingness-to-pay threshold.

CONCLUSIONS

When considering the societal costs of pneumococcal disease, PCV20 at ages 50 and 65 years in the general US population is a potentially economically viable strategy, particularly in Black cohorts.

Effectiveness of Adapted COVID-19 Vaccines and Ability to Establish Herd Immunity against Omicron BA.1 and BA4-5 Variants of SARS-CoV-2

The emergence of novel SARS-CoV-2 variants has raised concerns about the ability of COVID-19 vaccination programs to establish adequate herd immunity levels in the population. This study assessed the effectiveness of adapted vaccines in preventing SARS-CoV-2 infection and the ability of the adapted vaccines to establish herd immunity against emerging Omicron variants. A systematic literature review was conducted to estimate the absolute vaccine effectiveness (aVE) in preventing SARS-CoV-2 infection using adapted vaccines targeting Omicron variants. The ability of the adapted vaccines to establish herd immunity was assessed by taking into account the following factors: aVE, Ro values of SARS-CoV-2 and the use of non-pharmacological interventions (NPIs). This study found meta-analysis-based aVEs in preventing severe disease and SARS-CoV-2 infection of 56-60% and 36-39%, respectively. Adapted vaccines could not establish herd immunity against the Omicron BA.1 and BA.4-5 variants without using non-pharmacological interventions (NPIs). The adapted vaccines could establish herd immunity only by achieving >80% vaccination coverage, using NPIs with greater effectiveness and when 20-30% of individuals were already protected against SARS-CoV-2 in the population. New adapted COVID-19 vaccines with greater effectiveness in preventing SARS-CoV-2 infection must be developed to increase herd immunity levels against emerging SARS-CoV-2 variants in the population.

A panoramic view of hospitalized young children in the metropolitan area of the valley of Mexico during COVID-19

Objectives

This work provides an overview of young children's (aged 0-9) infectious diseases epidemiology, by exploring the link between various comorbid conditions, COVID-19, and death rate.

Methods

Public data on hospitalized young children was obtained from national databases of the Mexican health care system from 2020-2022. Data included age, year of entry, gender, the time between admission to death (hospitalization time), date of death, comorbidities, and admissions to the intensive care unit. Children were separated into age groups and frequencies were calculated. Binary regression models were developed to determine the correlation of comorbidities and COVID-19 to death as calculated by odds ratios (OR).

Results

From 2020-2022, there were 11,815 hospitalizations among young children, of which 15.98% were due to COVID-19, 2.55% of hospitalizations resulted in fatalities from which 32.45% of deaths were COVID-19 related. The highest case-calculated fatality ratio of COVID-19 infected young children was estimated at 7.04% by early 2020, but dropped to 2.11% by the end of the second semester of 2022. The most frequent comorbidities associated with their hospitalization and death for the general population were intubation (OR: 17.967), pneumonia (OR: 2.263), diabetes (OR: 7.301), cardiovascular diseases (OR: 1.528) and COVID-19 (OR: 261). For the COVID-19-positive group, the most impactful comorbidities were intubation (OR: 20.232), pneumonia (OR: 3.057), and diabetes (OR: 12.824).

Conclusion

Children's hospitalizations and deaths were common during the pandemic; wherein major comorbidities played an important role. Therefore, effective comorbidity management and vaccination programs are essential to reduce hospitalizations and deaths among young children.

Tübingen model study: large-scale introduction of rapid antigen testing in the population and the viral dynamics of SARS-CoV-2

Despite of contact restrictions, population mobility remains the main reason for the spread of SARS-CoV-2. The state of Baden-Württemberg (BW), Germany, approved a model study in Tübingen (TÜMOD) to evaluate how mandatory rapid diagnostic tests (RDT) could reduce transmission. Between 16 March and 24 April 2021, approximately 165,000 residents and visitors to the city were screened for SARS CoV-2 infection using Abbott Panbio™ COVID-19 Antigen rapid test device. We assessed incidences and recorded epidemiological characteristics in a subset of 4,118 participants recruited at three of the nine testing stations. PCR tests were performed in RDT-positives to determine the positive predictive value (PPV), and circulating variants of SARS-CoV-2 were identified by whole-genome sequencing. 2,282 RDT-negative samples were tested by pooled PCR to calculate the false negative rate (FNR). Viral load was compared between variants. 116 (3%) participants were positive by RDT, and of these, 57 (49%) were positive by PCR, 55 (47%) were negative. This resulted in a PPV of 51%. Of the 57 positives, 52 SARS-CoV-2 genomes were successfully sequenced. Of these, 50 belonged to the B.1.1.7 lineage, which had a high viral load (average Ct = 19). Of the 2,282 RDT negatives tested, all were PCR negative (FNR 0%). At the end of TÜMOD, the incidence in Tübingen, which was initially lower, had reached the incidence in the state of BW. While it is difficult to assess the impact of TÜMOD on incidence independent of confounding factors, further studies are needed to identify the effect of close-meshed testing on infection rates.

A simulation approach for COVID-19 pandemic assessment based on vaccine logistics, SARS-CoV-2 variants, and spread rate

Despite advances in clinical care for the coronavirus (COVID-19) pandemic, population-wide interventions are vital to effectively manage the pandemic due to its rapid spread and the emergence of different variants. One of the most important interventions to control the spread of the disease is vaccination. In this study, an extended Susceptible-Infected Healed (SIR) model based on System Dynamics was designed, considering the factors affecting the rate of spread of the COVID-19 pandemic. The model predicts how long it will take to reach 70% herd immunity based on the number of vaccines administered. The designed simulation model is modeled in AnyLogic 8.7.2 program. The model was performed for three different vaccine supply scenarios and for Turkey with ~83 million population. The results show that, with a monthly supply of 15 million vaccines, social immunity reached the target value of 70% in 161 days, while this number was 117 days for 30 million vaccines and 98 days for 40 million vaccines.

Humoral and cellular immunity of two-dose inactivated COVID-19 vaccination in Chinese children: A prospective cohort study

Children are the high-risk group for COVID-19, and in need of vaccination. However, humoral and cellular immune responses of COVID-19 vaccine remain unclear in vaccinated children. To establish the rational immunization strategy of inactivated COVID-19 vaccine for children, the immunogenicity of either one dose or two doses of the vaccine in children was evaluated. A prospective cohort study of 322 children receiving inactivated COVID-19 vaccine was established in China. The baseline was conducted after 28 days of the first dose, and the follow-up was conducted after 28 days of the second dose. The median titers of receptor binding domain (RBD)-IgG, and neutralizing antibody (NAb) against prototype strain and Omicron variant after the second dose increased significantly compared to those after the first dose (first dose: 70.0, [interquartile range, 30.0-151.0] vs. second dose: 1261.0 [636.0-2060.0] for RBD-IgG; 2.5 [2.5-18.6] vs. 252.0 [138.6-462.1] for NAb against prototype strain; 2.5 [2.5-2.5] vs. 15.0 [7.8-26.5] for NAb against Omicron variant, all p < 0.05). The flow cytometry results showed that the first dose elicited SARS-CoV-2 specific cellular immunity, while the second dose strengthened SARS-CoV-2 specific IL-2⁺ or TNF-α⁺  monofunctional, IFN-γ⁺ TNF-α⁺  bifunctional, and IFN-γ^- IL-2⁺ TNF-α⁺ multifunctional CD4⁺ T cell responses (p < 0.05). Moreover, SARS-CoV-2 specific memory T cells were generated after the first vaccination, including the central memory T cells and effector memory T cells. The present findings provide scientific evidence for the vaccination strategy of the inactive vaccines among children against COVID-19 pandemic.

Comparison of the Onset and End of Specific and Major Side Effects in Iranian Teenage Participants Vaccinated With COVID-19 Vaccine: Sinopharm and Soberana

Background

Clinical trials were conducted on children on side effects after vaccination. We tried to assess the frequency and onset of the main symptoms in children who were vaccinated. We aimed to evaluate early and delayed adverse effects after coronavirus disease 2019 (COVID-19) vaccine among Iranian pediatrics and adolescents in a national survey.

Methods

This cross-sectional study included people <18 years who received the Soberana (PastoCoVac) and Sinopharm vaccines since 2021. The basic information was gender, age, type of vaccine, and reaction after vaccination besides the main events that occurred for them. The required data were collected via a predetermined checklist by trained interviewers through phone calls by their parents or legal guardians. The independent t test and Fisher exact test were used. P values less than 0.05 were considered significant.

Results

A total of 11,042 participants (age range, 10-18 years) consisting of 5374 boys (47.8%) and 5768 girls (52.2%) were studied and 88.1% of the children (n = 9727) were vaccinated by Sinopharm and 11.9% (n = 1315) by Soberana. The data of kidney-related side effects had delayed improvement of side effects after the Sinopharm compared with the Soberana vaccines (P = 0.012). Cardiovascular and hematological side effects showed early-onset (P = 0.006) and delayed improvement of side effects (P = 0.002) after the Soberana vaccine compared with the Sinopharm vaccine. Neurological side effects showed delayed improvement of side effects after the Soberana vaccine compared with the Sinopharm vaccine (P = 0.027). Joint-related side effects showed early-onset (P = 0.004) and delayed improvement of side effects (P = 0.023) after the Soberana vaccine compared with the Sinopharm vaccine. Respiratory side effects showed delayed improvement of side effects after the Soberana vaccine compared with the Sinopharm vaccine (P = 0.013), and dermatological side effects showed early-onset (P = 0.050) and delayed improvement of side effects (P = 0.035) after the Soberana vaccine compared with the Sinopharm vaccine. There was not any statistically significant difference regarding gastrointestinal side effects between the 2 vaccines (P > 0.05).

Conclusion

The cardiovascular and hematological, joint-related (non-neurologic musculoskeletal) and dermatological side effects after the Soberana vaccine appear earlier and end later compared with the Sinopharm vaccine. Improvement of renal side effects in the Sinopharm vaccine group and improvement of neurological and respiratory side effects in the Soberana vaccine group occurred with delay compared with other vaccines.

Parental Perceptions and Barriers towards Childhood COVID-19 Vaccination in Saudi Arabia: A Cross-Sectional Analysis

Introduction: The vaccination of children against Coronavirus disease (COVID-19) is a prime area of focus around the globe and is considered a pivotal challenge during the ongoing pandemic. This study aimed to assess parents′ intentions to vaccinate their children and the barriers related to pediatric COVID-19 vaccination. Methodology: An online web-based survey was conducted to recruit parents with at least one child under the age of 12 years from Saudi Arabia’s Al-Jouf region. The parental intentions to vaccinate children were assessed via six items, while barriers against vaccination were assessed through seven items in validated study instrument. A 5-point Likert scale was used to record the responses of parents regarding both their intentions and barriers. Results: In total, 444 parents (28.41 ± 7.4 years, 65% females) participated in this study. Almost 90% of parents were vaccinated against COVID-19 but only 42% of parents intended to vaccinate their children. The mean intention score was 2.9 ± 1.36. More than one-third of study participants had no plan to vaccinate their children against COVID-19. The majority of the respondents agreed to vaccinate their children if vaccination was made compulsory by the government (relative index: 0.76, 73%). Out of seven potential barriers analyzed, concerns over vaccine safety and side effects were ranked highest (RII: 0.754), reported by 290 (65%) participants. In multivariate logistic regression, significant predictors of parental intention to vaccinate children were the increased education level of the parents (secondary education: OR = 3.617, p = 0.010; tertiary education: OR = 2.775, p = 0.042), COVID-19 vaccination status (vaccinated: OR = 7.062, p = 0.003), mother’s involvement in decisions regarding the child’s healthcare (mother: OR 4.353, p < 0.001; both father and mother: OR 3.195, p < 0.001) and parents’ trust in the vaccine’s safety (OR = 2.483, p = 0.022). Conclusions: This study underscored the low intention among parents to vaccinate their children against COVID-19. Vaccination intention was found to be associated with education, parents’ vaccination status, the mother’s involvement in healthcare decisions, and parents’ trust in the vaccine’s safety. On the other hand, parents’ concerns over the safety and efficacy of the COVID-19 vaccine were widely reported as barriers to childhood vaccination. The health authorities should focus on addressing parental concerns about vaccines to improve their COVID-19 vaccination coverage.

I have decided about my COVID-19 vaccine, what about my child?

Vaccination has been instrumental in controlling the COVID-19 pandemic, with numbers of new cases decreasing rapidly even as restrictions to control the spread of the virus were removed. The first stage of the vaccination campaign in Israel covered individuals aged 16 and older, following the U.S. Food and Drug Administration's approval of the vaccine. While the campaign was later extended to those aged 12 and older, some parents continue to have doubts and concerns about the vaccine. Data were collected via an online questionnaire during April 2021; 516 parents participated. This research adopted a holistic approach that combines factors relating to vaccine acceptance previously reported in the literature. The acceptance of pediatric COVID-19 vaccination among parents varied by their children's age groups, at 44.7%, 53.2%, and 66.4% among parents with children aged 0-6, 6-12, and 12-16, respectively. The results of this study indicate that different sets of variables affect the willingness of parents to vaccinate their children, depending on their child's age. Moreover, a holistic approach is necessary in order to correctly verify the significant variables. Parents who evaluate the vaccine as more beneficial have a higher probability of being willing to vaccinate. In addition, for ages 12-16, parental willingness to vaccinate is associated with access to information, trust, and neighborhood norms. Those evaluating information about the vaccine as more fake news show higher probability to vaccinate their children. The timing of the survey is highly relevant, especially considering the uncertainty about the effectiveness and side effects of the vaccine.

Determinants of the willingness of medical staff to vaccinate their children with a booster dose of the COVID-19 vaccine in Taizhou, China

The study aimed to determine the willingness of medical staff to have their children vaccinated with a COVID-19 booster in Taizhou, China. From March 21 to April 19, 2022, an online questionnaire survey was conducted to assess the willingness of medical staff to vaccinate their children with a booster dose of the COVID-19 vaccine. Of the 1,252 medical staff in a tertiary grade hospital in Taizhou who were invited to answer the structured questionnaire, 514 (41.1%) samples had valid information for further data analysis. Four hundred thirty-seven medical staff (85.0%) were willing to have their children receive vaccine boosters. After adjustments for confounding factors, the opinion ('Do you think your child needs a booster vaccination against COVID-19?') (yes vs. no, OR = 6.91, 95% CI: 3.29-14.54), the viewpoint ('What are your thoughts the effectiveness of COVID-19 vaccine boosters for children?' (≥12 vs. <12, OR = 13.81, 95% CI: 4.03-), and the attitude ('Your attitude to whether your child is boosting the Covid-19 vaccine?') (yes vs. no, OR = 4.66, 95% CI: 2.30-9.44) were significantly associated with their willingness to have their children receive a COVID-19 vaccine booster. A moderate percentage of the respondents expressed willingness to have their children receive booster vaccines. The findings implied that factors affecting medical staffs' willingness to vaccinate their children with a COVID-19 vaccine booster included viewpoint, opinion, and attitudes.

Do we need to vaccinate every child against COVID-19: What evidence suggests-A systematic review of opinions

It is still debatable whether all children should receive the COVID-19 vaccine. The comparatively mild cases and low risk of COVID-19 in children compared to adults, as well as the lack of clarity on the relative effects of the disease and vaccine, indicate that the risk-benefit ratio of vaccination in children is more nuanced. To consider and highlight the complexity of policy decisions regarding COVID-19 vaccination in children, we outlined the points regarding for and against vaccination of children against COVID-19 in this systemic review. Using Medical Search Headings (MeSH) terms and keywords, we searched PubMed, PubMed Central, Scopus, and Google Scholar. The primary search term was COVID-19 vaccination (all synonyms), factors (all synonyms), and among children (all synonyms). A total of 367 articles were searched. Finally, 64 articles met the inclusion criteria and were included in the review. The major theme/tone of 28 (43.75%) articles was in favor of children's COVID vaccination, and they were highlighting the positive factors, whereas the major theme/tone of 20 (31.25%) articles was against it. Approximately 16 (25.0%) articles were in a neutral position. Major factors highlighted by articles in favor of childhood COVID vaccination were as follows: the increasing rate of disease burden (29 articles), prevention of interruption of academic activities of children or school reopening (24 articles), and a role in defense against COVID infection (21 articles). Major factors against childhood vaccination were as follows: mild infection among children (27 articles), ethical concerns and legal problems regarding the consent of minors (17 articles), and vaccine hesitancy among parents for childhood vaccination (11 articles). Whereas, factors of uncertainty were the role in the reduction of community transmission (19 articles), protection against MIS-C (10 articles), and defense against long COVID (7 articles). Considering all the factors of COVID-19 disease progression among children, a cautious approach will be essential before proceeding with COVID-19 vaccination in children.

Parental Attitudes Towards Vaccination Against COVID-19 in China During Pandemic

Purpose

The Chinese government has authorized the emergency use of an inactivated vaccine for COVID-19 in children and adolescents aged 3 to 17 years. This study aimed to investigate parents' attitudes towards vaccinating their children against COVID-19 and influencing factors.

Patients and Methods

Through an online questionnaire survey, we collected self-reported children's demographic characteristics, physical conditions and parents' attitudes towards COVID-19 vaccination for children. The parents in the unwilling group received online consultation about the benefits and risks of COVID-19 vaccine and were asked to complete the questionnaire again.

Results

A total of 868 participants were recruited from July 2021 to August 2021 in Nanjing, China. Overall, 76.0% of parents were willing to accept vaccination for children. Parents' willingness increased with children's age (P=0.018) and height (P=0.034), but decreased if the children fell sick within previous one month (P=0.030). Most of the unwilling parents gave a higher score to the risk of vaccination (53.76 VS 40.18). Unsafety (63.8%) and unfamiliarity (24.0%) were their major concerns. After consultation with a health worker, 24% of the unwilling parents turned willing.

Conclusion

Children's age and recent physical condition are related to parents' attitudes towards vaccination for children against COVID-19. The major concerns of parents are unsafety and unfamiliarity. Parents view health workers as a reliable source of vaccine information. A successful consultation with health workers to understand the benefits and risks of vaccination can increase parents' willingness. This study provides insight into parents' attitudes towards vaccination for children against COVID-19 in China and related influencing factors. Our findings could be referenced in establishing policies for vaccinating children against COVID-19 in China.

Immunologic response, Efficacy, and Safety of Vaccines against COVID-19 Infection in Healthy and immunosuppressed Children and Adolescents Aged 2 - 21 years old: A Systematic Review and Meta-analysis

Children and adolescents form a large proportion of societies and play an important role in the transmission of COVID-19. On the other hand, their education, mental and physical wellness, and safety are compromised which makes vaccination a crucial step to return to normal life. In the current systematic review, the COVID-19 vaccination was evaluated in a total of 50,148 children and adolescents in 22 published studies and 5,279 participants in two ongoing clinical trials. The study was registered in the PROSPERO with the ID# CRD42022303615. Data were collected about multiple vaccines including BNT162b2 (Pfizer), mRNA-1273 (Moderna), JNJ-78436735 (Johnson and Johnson), CoronaVac (Sinovac), BBIBP-CorV (Sinopharm), adenovirus type-5-vectored vaccine, ZyCov-D, and BBV152 (COVAXIN). The immune response and efficacy of such vaccines were 96% - 100% in healthy children and adolescents and were also acceptable in those with underlying diseases and suppressed immune systems. The current systematic review revealed favorable safety profiles of employed vaccines in children and adolescents; however, adverse reactions such as myocarditis and myopericarditis were reported which were transient and resolved entirely. Consequently, vaccinating children and adolescents aged 2 - 21 years old is beneficial to abort the COVID-19 pandemic. Moreover, the risk-benefit assessments revealed favorable results for vaccinating children and adolescents, especially those with underlying diseases and immunosuppressed conditions, alongside adults to prevent transmission, severe infection, negative outcomes, and new variants formation. Also, according to the meta-analysis, the efficacy and immune response of vaccines after the first and second doses were 91% and 92%, respectively. Meanwhile, overall immune response for all vaccines was 95% and 91% for Pfizer vaccine.

COVID-19 Vaccination in Pediatric Population: A Necessity or Obstruction to the Protection of the Right to Health? Biojuridical Perspective

One of the most recently debated topics worldwide is the mass vaccination of children against coronavirus disease 2019 (COVID-19). Next, the risk/benefit ratio of COVID-19 vaccination and infection in children are compared. Nonetheless, the real question in this debate is as follows: Does the vaccine represent a necessary tool or is it an obstacle in protecting the right to health? From a public health point of view, the Supreme Court of Nova Scotia, in Canada, recommends COVID-19 vaccination in the pediatric population. Based on Article 25 of the Draft Articles on State responsibility, vaccination can be considered a social act necessary for protecting the individual's right to health. The 1989 New York Convention on the Rights of the Child and the European Regulation number 219/1111 state that the opinion of a minor aged >12 years is considerable. However, this validity of opinion is related to age and degree of discernment. The onset of adverse events following the administration of the COVID-19 vaccine may lead to compensation in the near future. Recent studies have identified a new COVID-19-related pediatric pathology, known as multisystem inflammatory syndrome. Other studies have demonstrated that myocarditis in the pediatric population might occur following COVID-19 vaccine administration. In June 2021 in the USA, the Center for Control and Prevention of Infectious Diseases Advisory Committee on Immunization Practices declared that the benefits of vaccination against COVID-19 in the pediatric population outweighed the risks. In the meantime, whereas the bioethical debate remains open, monitoring the real risk/benefit ratio of vaccination in the pediatric population is crucial.

Caregivers' Intention to Vaccinate Their Children Under 12 Years of Age Against COVID-19: A Cross-Sectional Multi-Center Study in Milan, Italy

The impact of Coronavirus disease 2019 (COVID-19) on the pediatric population is increasingly recognized. A widespread vaccination in childhood would provide benefits for children and might help ending the pandemic by enhancing community protection. Following recent approval by the European Medicines Agency (EMA) of Comirnaty (Pfizer-BioNTech) for children aged 5-11 years, we aimed to investigate caregivers' intention to vaccinate their children <12 years of age against COVID-19. A structured questionnaire was administered to caregivers of children aged <12 years visiting the Emergency Department or the outpatient clinics in three major hospitals of Milan, Italy, from 20 September to 17 October 2021. A total of 612 caregivers were invited to participate and 604 accepted (response rate >98%). Three questionnaires were excluded due to compiling errors and 601 were included in the analysis. A total of 311 (51.7%) caregivers stated they would have their child vaccinated, 138 (23%) would refuse to vaccinate their child and 152 (25.3%) were unsure. The intention to vaccinate the child was higher in caregivers vaccinated against COVID-19, in those with a bachelor's degree or higher level of education, and in those with friends/acquaintances who became ill or died due to COVID-19. This study shows that increasing efforts are necessary to provide evidence-based tailored information to caregivers and to promote vaccination in this pediatric age group.

Parents' Hesitancy to Vaccinate Their Children Against COVID-19, a Country-Wide Survey

Objective

Parents' hesitancy (PH) toward childhood vaccination, including the vaccine of coronavirus disease (COVID-19), is one of the top public health threats. We aim to assess the PH toward children COVID-19 vaccination as compared to PH toward children routine vaccination among the residents of Saudi Arabia.

Method

Before the official approval of children's COVID-19 vaccination in the country, a cross-sectional study using an electronically distributed survey was performed. Responses from parents of children younger than 18 years of age were accepted. The Oxford COVID-19 vaccine hesitancy scale (OC19-VHS) and the routine vaccination hesitancy scale (R-VHS) were used. Parents were classified as hesitant, non-hesitant, and unsure.

Results

Between June 18th-30th, 2021, we included 1,052 parents. More than half of the parents were positive toward the childhood COVID-19 vaccination (63%) while 10% were unsure. Higher parental hesitancy toward children COVID-19 vaccination among mothers, parents younger than 40 years, did not receive COVID-19 nor influenza vaccines, had higher educational levels, and parents who recovered from COVID-19 infection. Hesitancy was mainly driven by the novelty of the vaccines and the fear of serious adverse effects. Compared to the routine vaccination, parents were more hesitant toward COVID-19 vaccination (6 vs. 27%).

Conclusion

Generally, parents in Saudi Arabia were positive toward children's COVID-19 vaccination. Focused education to reassure hesitant parents on the safety of the vaccine is essential to achieve larger vaccination coverage.

Percentages of Vaccination Coverage Required to Establish Herd Immunity against SARS-CoV-2

The pandemic associated with SARS-CoV-2 is a worldwide public health challenge. The WHO has proposed to achieve 70% COVID-19 vaccination coverage in all countries by mid-2022. Nevertheless, the prevention strategy based on COVID-19 vaccination and other applied prevention measures has not been sufficient to prevent SARS-CoV-2 epidemic waves. This study assessed the vaccination coverage that would be required to establish herd immunity against SARS-CoV-2, taking into account virus transmissibility (Ro values from 1.1 to 10) and COVID-19 vaccination effectiveness. The study found that high percentages of vaccination coverage and high levels of vaccination effectiveness are necessary to block the transmission of Omicron and other SARS-CoV-2 variants with greater infectious capacity. COVID-19 vaccination programs could establish herd immunity against SARS-CoV-2, with Ro values ranging from 3 to 10 and levels of COVID-19 vaccination effectiveness of 70-100%. Factors reducing COVID-19 vaccination effectiveness (emergent variants, infections among vaccinated individuals, high risk individuals) and factors increasing SARS-CoV-2 transmissibility (close settings) increased the percentages of vaccination coverage that would be required to establish herd immunity. Two measures should be implemented to establish herd immunity against SARS-CoV-2: (1) achieve ≥ 90% COVID-19 vaccination coverage in all countries worldwide, and (2) increase the effectiveness of COVID-19 vaccines in preventing Omicron infection to at least 88%.

Influence of Perceived Adolescent Vaccination Desire on Parent Decision for Adolescent COVID-19 Vaccination

PURPOSE

The purpose of this study was to assess the influence of adolescents' desire for COVID-19 vaccination on their parents' vaccination decision for their adolescent.

METHODS

We surveyed an internet-based panel of 1,051 parents of 1,519 adolescents aged 11-18 years from February to March 2021 about their adolescent's desire for COVID-19 vaccination and whether they consider this desire in their vaccination decision for the adolescent. We used multivariable Poisson regression to assess associations with parent-stated likelihood of adolescent vaccination.

RESULTS

A total of 58.3% of parents reported that they and their adolescents had the same vaccination desire; similarly, 58.3% considered their adolescent's desire in their vaccination decision. These latter parents were more likely to vaccinate their adolescent than parents who did not consider their adolescent's desire (adjusted risk ratio = 1.25 [95% confidence interval = 1.05-1.50]).

DISCUSSION

Most parents considered their adolescent's desire for COVID-19 vaccination. These parents were more likely to state that they will have their adolescent receive a COVID-19 vaccine.

COVID-19 vaccines for children and adolescents in Africa: aligning our priorities to situational realities

The evolving COVID-19 pandemic is an unprecedented global public health crisis that continues to have a major impact on the African continent. Most countries within Africa are facing significant challenges vaccinating their populations for COVID-19. Inadequate COVID-19 vaccine supply, weaknesses in health system infrastructure, COVID-19 misinformation and disinformation, and ineffective health risk communication are contributing to low adult vaccination rates on the continent. Without sufficient COVID-19 vaccine coverage on the African continent, the prolonged social, economic and health impacts of this public health crisis are likely to exacerbate pre-existing social-structural issues in this part of the world. In this paper, we highlight trends in SARS-CoV-2 infections among children and adolescents (CA), compare COVID-19 vaccination patterns in Africa to those in high-income countries, and discuss some of the benefits, challenges and unknowns associated with vaccinating CA for COVID-19. In light of ongoing COVID-19 vaccine supply challenges and the slow progress that the African continent is making towards vaccinating the adult population, we suggest that the immediate priority for Africa is to accelerate COVID-19 vaccinations among adults (particularly high-risk populations) and vulnerable CA (ie, those who are immunocompromised and/or living with certain medical conditions). Accelerating the roll-out of COVID-19 vaccines and rapidly achieving high levels of vaccination coverage in the adult population will free up capacity to vaccinate CA sooner rather than later. While we hope that COVID-19 vaccines will soon become available to CA throughout Africa, countries must continue to prioritise non-pharmaceutical interventions.

The role of childrens' vaccination for COVID-19-Pareto-optimal allocations of vaccines

COVID-19 vaccines have been approved for children of age five and older in many countries. However, there is an ongoing debate as to whether children should be vaccinated and at what priority. In this work, we use mathematical modeling and optimization to study how vaccine allocations to different age groups effect epidemic outcomes. In particular, we consider the effect of extending vaccination campaigns to include the vaccination of children. When vaccine availability is limited, we consider Pareto-optimal allocations with respect to competing measures of the number of infections and mortality and systematically study the trade-offs among them. In the scenarios considered, when some weight is given to the number of infections, we find that it is optimal to allocate vaccines to adolescents in the age group 10-19, even when they are assumed to be less susceptible than adults. We further find that age group 0-9 is included in the optimal allocation for sufficiently high values of the basic reproduction number.

Parents’ and Guardians’ Willingness to Vaccinate Their Children against COVID-19: A Systematic Review and Meta-Analysis

COVID-19 vaccination for children is crucial to achieve herd immunity. This is the first systematic review and meta-analysis to estimate parents’ and guardians’ willingness to vaccinate their children against COVID-19 and identify the determinants of vaccination intention. Systematic research was performed on the two databases (PubMed and EMBASE) from inception to 6 November 2021. Acceptance rates were pooled by use of a random-effects model and all predictors of vaccine acceptance were identified according to the health belief model (HBM) framework. This analysis was registered with PROSPERO (CRD42021292326) and reported in compliance with the PRISMA guidelines. Of 452 identified records, 29 eligible studies were included (N = 68,327 participants). The estimated worldwide vaccination acceptance rate was 61.40% (95% CI: 53.56–68.69%, I² = 99.3%), ranging from 21.6% to 91.4% across countries and regions. In the determinant assessment, the age of parents and guardians, access to scientific information and recommendations, routine and influenza vaccination behavior, and the willingness of parents and guardians to vaccinate themselves were potentially significant predictors of the vaccination willingness. Given the limited quality and quantity of included articles, future studies with a rigorous design will be necessary for the confirmation of our findings.

Recent Insights into COVID-19 in Children and Clinical Recommendations

Pediatric coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C) have been recognized in multiple countries globally. In this review, we provide recent insights into SARS-CoV-2 infection in children from epidemiological, clinical, and laboratory perspectives, including reports on the disease course and therapy. We highlight key features of SARS-CoV-2 infection in children, the relationship between MIS-C and Kawasaki disease, and summarize treatment guidelines for COVID-19 in children from institutional protocols from Colombia, case reports, recommendations based on expert consensus, and official statements from organizations such as the World Health Organization (WHO), United States Center for Disease Control (CDC), Colombian Association of Infectious Diseases, and the Colombian Society of Pediatrics. Finally, we discuss gaps in research with suggestions for future research on the pathogenesis underlying pediatric COVID-19.

COVID-19 prevention behaviors, trust, and intent to vaccinate among youth at risk for HIV

The current study examines COVID-19 prevention behaviors and vaccine intentions among 83 youth at high risk for HIV. Most youth self-identified as Latinx (52%), cisgender men (84%), and homosexual (66%). Youth self-reported COVID-19 prevention behaviors and intentions to vaccinate. Participants reported wearing face masks, washing hands, and staying six feet apart, but fewer reported leaving home only for essential needs. About one-third reported that they would not get a vaccine, and lack of trust in their doctors and the government were significantly associated with non-intention. To improve efforts towards herd immunity, interventions to improve health messaging from trusted sources for at-risk youth may be necessary to achieve higher vaccine uptake.

Students' age and parental level of education influence COVID-19 vaccination hesitancy

Widespread vaccination in pursuit of herd immunity has been recognized as the most promising approach to ending the global pandemic of coronavirus disease 19 (COVID-19). The vaccination of children and adolescents has been extensively debated and the first COVID-19 vaccine is now approved in European countries for children aged > 12 years of age. Our study investigates vaccination hesitancy in a cohort of German secondary school students. We assessed 903 students between age 9 and 20 in the period between 17 May 2021 and 30 June 2021. 68.3% (n = 617) reported intention to undergo COVID-19 vaccination, while 7% (n = 62) did not want to receive the vaccine and 15% (n = 135) were not yet certain. Age and parental level of education influenced COVID-19 vaccine hesitancy. Children under the age of 16 as well as students whose parents had lower education levels showed significantly higher vaccine hesitancy.  Conclusion: Identifying subsets with higher vaccination hesitancy is important for targeting public information campaigns in support of immunization. What is Known: • The willingness to receive COVID-19 vaccination among adults in Europe is about 70%, but data for children and adolescents is lacking. • The lack of immunization in younger cohorts represents a significant barrier to achieving herd immunity, and also leaves children and adolescents vulnerable to acute and long-term morbidity from natural COVID-19 infections. What is New: • Intention-to-vaccinate among children and adolescents is high (~ 70%); conversely, vaccination hesitancy is low. • Age and parental level of education influenced COVID-19 vaccine hesitancy among children and adolescents.

Management of pleural empyema in a 12-year-old obese patient with COVID-19: a pediatric case report

BACKGROUND

With the ongoing coronavirus disease (COVID-19) pandemic, along with the development of new mutations of the virus and an increase in the number of cases among pediatrics, physicians should be aware and alerted on the atypical presentations of the disease, especially in less expected individuals.

CASE PRESENTATION

Here we present a 12-year-old obese boy (BMI = 37.5 kg/m2) who presented with empyema, which was following SARS-CoV-2 infection. The patient had no history of fever. Due to the onset of dyspnea, a chest tube was inserted for him which was later altered to a pleural drainage needle catheter.

CONCLUSION

Our case is the first report of COVID-19 presenting as empyema among pediatrics. Pleural empyema should be considered as a rare complication of COVID-19. Since there is still no guideline in the management of empyema in the context of COVID-19, delay in diagnosis and intervention may cause morbidity and mortality in children.

An ethical analysis of vaccinating children against COVID-19: benefits, risks, and issues of global health equity

COVID-19 vaccination of children has begun in various high-income countries with regulatory approval and general public support, but largely without careful ethical consideration. This trend is expected to extend to other COVID-19 vaccines and lower ages as clinical trials progress. This paper provides an ethical analysis of COVID-19 vaccination of healthy children. Specifically, we argue that it is currently unclear whether routine COVID-19 vaccination of healthy children is ethically justified in most contexts, given the minimal direct benefit that COVID-19 vaccination provides to children, the potential for rare risks to outweigh these benefits and undermine vaccine confidence, and substantial evidence that COVID-19 vaccination confers adequate protection to risk groups, such as older adults, without the need to vaccinate healthy children. We conclude that child COVID-19 vaccination in wealthy communities before adults in poor communities worldwide is ethically unacceptable and consider how policy deliberations might evolve in light of future developments.

Socio-demographic, psychological, and experiential predictors of COVID-19 vaccine hesitancy in South Korea, October-December 2020

Vaccine hesitancy is the primary barrier to controlling the COVID-19 pandemic in South Korea. We used logistic multivariate regression modeling to investigate (1) the prevalence and reasons for COVID-19 vaccine hesitancy, (2) sub-groups that had higher rates of vaccine hesitancy, and (3) vaccine hesitancy predictors. We used a national survey of representatively sampled households (n = 13,021 adults) from October to December 2020. A self-report questionnaire asked about vaccination intention and reasons for hesitancy and gathered data on socio-demographic, demographic, psychological, and experiential factors. Our study indicated that 39.8% of the participants answered that they hesitated or refused to be vaccinated. The most common reason for vaccine hesitancy was a lack of confidence in the COVID-19 vaccine (77.9%). Less or no fear of COVID-19 (OR = 2.08, 95% CI = 1.92–2.26; OR = 1.79, 95% CI = 1.54–2.08), unstable job status (OR = 1.42, 95% CI = 1.18–1.70), decreased family income (OR = 1.40, 95% CI = 1.21–1.61), and worsening health status (OR = 1.38, 95% CI = 1.13–1.68) were predictors of vaccine hesitancy. Younger age, no religious affiliation, political conservatism, and lower family income were also significantly associated with vaccine hesitancy. Effective health communication and policies need to consider the target subgroup population and predictors of vaccine hesitancy to attain herd immunity at an early stage.

Interaction between age and health conditions in the intention to be vaccinated against COVID-19 in Thailand

To study the sociodemographic factors as well as the interaction between age groups and health conditions in relation to the intention of being vaccinated against coronavirus disease 2019 (COVID-19) in Thailand. A cross-sectional survey was conducted during the "third wave" of the COVID-19 pandemic in Thailand (March to April 2021). The survey was uploaded and administered via the online survey platform of Google™. Thai citizens aged >18 years completed the survey. All factors that predicted the vaccine intention (VI) among participants were measured and analyzed using logistics regression and cross-tabulation. Among 862 participants, 55.6% said they were likely to get a COVID-19 vaccine. From the finding of the logistic regression, men were more likely to be vaccinated than women. Respondents with more than three health conditions were less likely to get vaccinated compared with those without any health conditions. People at a higher risk of health conditions had the lowest VI in any age group. Among the older age group, the number of health conditions affected the VI. The potential harmful side effects of a COVID-19 vaccine was the main reason for vaccine hesitancy. Overall, ~56% of respondents to an online questionnaire intended to become vaccinated against COVID-19. The older age group with a high risk of health conditions had the lowest VI even though this group should get the vaccine first. Therefore, there is an urgent need to design an education strategy to overcome such vaccine hesitancy.

An ethical analysis of vaccinating children against COVID-19: benefits, risks, and issues of global health equity

COVID-19 vaccination of children over 12 has begun in various high-income countries with regulatory approval and general public support, but largely without careful ethical consideration. This trend is expected to extend to other COVID-19 vaccines and lower ages as clinical trials progress. This paper provides an ethical analysis of COVID-19 vaccination of healthy children. Specifically, we argue that it is currently unclear whether routine COVID-19 vaccination of healthy children is ethically justified in most contexts, given the minimal direct benefit that COVID-19 vaccination provides to children, the potential for rare risks to outweigh these benefits and undermine vaccine confidence, and substantial evidence that COVID-19 vaccination confers adequate protection to risk groups, such as older adults, without the need to vaccinate children. We conclude that child COVID-19 vaccination in wealthy communities before adults in poor communities worldwide is ethically unacceptable and consider how policy deliberations might evolve in light of future developments.

Plans to Vaccinate Children for Coronavirus Disease 2019: A Survey of United States Parents

In a national survey of 2074 US parents of children ≤12 years of age conducted in March 2021, 49.4% reported plans to vaccinate their child for coronavirus disease 2019 when available. Lower income and less education were associated with greater parental vaccine hesitancy/resistance; safety and lack of need were primary reasons for vaccine hesitancy/resistance.

COVID-19 vaccine-taking hesitancy among Bangladeshi people: knowledge, perceptions and attitude perspective

Several novel efforts have been put forth to make a readily available vaccine against the global pandemic of COVID-19. However, there seems to appear vaccine-taking hesitancy among the general people. Against this backdrop, this current study sets to assess the vaccine-taking intention, ways to overcome the vaccine-taking reluctance among Bangladeshi people and explore their knowledge, perceptions, and attitude toward the COVID-19 vaccine. To this end, this study leveraged on a cross-sectional survey, which was consisted of 1377 respondents covering the eight divisions of Bangladesh. The descriptive statistical method and ordinal logistics regression were employed to explore and rationalize our study outlined objectives. Empirical findings revealed that approximately 71% of the respondents had adequate knowledge about the COVID-19 vaccine, whereas 46% of the respondents were willing to be vaccinated against COVID-19 while the rest of the respondents were hesitant to take the vaccine. However, concern about the potential side effects was one of the core reasons for vaccine-taking hesitancy. Assuring the common people about vaccine safety and efficacy, along with easing the registration procedure, can ameliorate people's confidence to get vaccinated. Meanwhile, about 60% of the respondents believed that a vaccine could help Bangladesh win the battle against COVID-19 and will allow back to normal life. Although the government has taken some pragmatic action steps to promote the vaccination rate, it is recommended that the mass vaccination program should be extended to the grassroots level with proper extension community support and easing the registration process.

Vaccine hesitancy towards childhood immunizations as a predictor of mothers' intention to vaccinate their children against COVID-19 in Saudi Arabia

Background

Despite the success of childhood immunization in reducing vaccine-preventable diseases, vaccine hesitancy is now a global health threat to this achievement. The current COVID-19 pandemic may change the picture of vaccine hesitancy toward childhood immunizations, which could influence the mothers’ intention to vaccinate their children against COVID-19.

Aim

To measure the prevalence and related factors of vaccine hesitancy towards childhood immunization during the era of COVID-19 along with the prevalence of mothers’ intention to vaccinate their children the future COVID-19 and its association with childhood vaccine hesitancy.

Methods

Cross sectional study was conducted among 270 Saudi mothers attending outpatient clinics at King Abdullah University Hospital (KAAUH) in Riyadh by purposive sampling technique. Data were collected from January to February 2021 using SAGE Group standardized questionnaire.

Results

Although most mothers strongly agree on the importance of the vaccine (79%), almost one-fourth of mothers were hesitant towards childhood immunization (24.31%). Similar percentage of mothers’ intended to vaccinate their children against COVID-19 in the next 6 months was reported (24%). Vaccine hesitancy was found to be a significant predictor of mothers’ intention. Mothers’ education level was significantly associated with being hesitant towards childhood immunization as well as the intention to accept the future COVID-19 vaccine (p < 0.05). Main reason that was highly significantly associated with being hesitant is the concerns about the side effect (50%).

Conclusion

The present study reported a considerable percentage of mothers who are hesitant towards childhood immunization which predicts their intension to vaccinate towards COVID19 and is associated with the level of education.

Parents' willingness and attitudes concerning the COVID-19 vaccine: A cross-sectional study

INTRODUCTION

This study aimed to evaluate the parents' willingness and attitudes concerning the COVID-19 vaccine.

METHOD

This cross-sectional study was performed using a self-administered online survey, covering parents' and their children's characteristics, parents' willingness and attitudes towards the COVID-19 vaccine. A total of 1035 parents participated.

RESULTS

Analysis showed that 36.3% of parents were willing to have their children receive the COVID-19 vaccine and that 59.9% were willing to receive it themselves. In addition, 83.9% were willing to have their children vaccinated with the COVID-19 vaccine if the mortality rates associated with COVID-19 in children increased following a mutation. After adjusting for significant variables, willingness to receive the COVID-19 vaccine (AOR = 24.91; 95% CI = 10.93-56.76), willingness for their children to participate in a COVID-19 vaccine trial (AOR = 11​.87; 95% CI = 2.41-58.40] and advising others to receive the COVID-19 vaccine [AOR = 7.82; 95% CI = 2.50-24.49] were associated with greater parents' willingness for their children to receive the COVID-19 vaccine.

CONCLUSIONS

Parents' willingness for their children to receive the COVID-19 vaccine was low. The only characteristics of either parents or children found to affect the parents' willingness for children to receive the COVID-19 vaccine was the parents being healthcare workers. Parents' willingness and positive attitudes towards the COVID-19 vaccine are factors that increase acceptance of the COVID-19 vaccine for their children.

Vaccines for COVID-19: learning from ten phase II trials to inform clinical and public health vaccination programmes

Public health professionals and clinicians, in many countries, are immersed in the ongoing and upcoming vaccination programmes for COVID-19. Published information from vaccine trials is complex. There are important and helpful insights about the nature of the available and forthcoming vaccines, immune responses and side-effects from phase II trials. We have systematically summarised information from 10 such trials on the nature of the vaccines, exclusions from the trials, immunological effects and side-effects. Some important information within these trial reports is not available in the phase III trial articles, so a complete picture requires examination of phase II and phase III trials for each vaccine. We recommend our systematic approach for the examination of other upcoming COVID-19 vaccine phase II and III trials.

What defines an efficacious COVID-19 vaccine? A review of the challenges assessing the clinical efficacy of vaccines against SARS-CoV-2

The novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused more than 1 million deaths in the first 6 months of the pandemic and huge economic and social upheaval internationally. An efficacious vaccine is essential to prevent further morbidity and mortality. Although some countries might deploy COVID-19 vaccines on the strength of safety and immunogenicity data alone, the goal of vaccine development is to gain direct evidence of vaccine efficacy in protecting humans against SARS-CoV-2 infection and COVID-19 so that manufacture of efficacious vaccines can be selectively upscaled. A candidate vaccine against SARS-CoV-2 might act against infection, disease, or transmission, and a vaccine capable of reducing any of these elements could contribute to disease control. However, the most important efficacy endpoint, protection against severe disease and death, is difficult to assess in phase 3 clinical trials. In this Review, we explore the challenges in assessing the efficacy of candidate SARS-CoV-2 vaccines, discuss the caveats needed to interpret reported efficacy endpoints, and provide insight into answering the seemingly simple question, "Does this COVID-19 vaccine work?"

COVID-19 and Pediatric Asthma: Clinical and Management Challenges

Asthma is the most frequent chronic condition in childhood and a current concern exists about asthma in the pediatric population and its risk for severe SARS-CoV-2 infection. Although all ages can be affected, SARS-CoV-2 infection has lower clinical impact on children and adolescents than on adults. Fever, cough and shortness of breath are the most common symptoms and signs in children; wheezing has not been frequently reported. Published studies suggest that children with asthma do not appear to be disproportionately more affected by COVID-19. This hypothesis raises two issues: is asthma (and/or atopy) an independent protective factor for COVID-19? If yes, why? Explanations for this could include the lower IFN-α production, protective role of eosinophils in the airway, and antiviral and immunomodulatory proprieties of inhaled steroids. Additionally, recent evidence supports that allergic sensitization is inversely related to ACE2 expression. Obesity is a known risk factor for COVID-19 in adults. However, in the childhood asthma–obesity phenotype, the classic atopic Th2 pattern seems to predominate, which could hypothetically be a protective factor for severe SARS-CoV-2 infection in children with both conditions. Finally, the return to school activities raises concerns, as asymptomatic children could act as vectors for the spread of the disease. Although this is still a controversial topic, the identification and management of asymptomatic children is an important approach during the SARS-CoV-2 epidemic. Focus on asthma control, risk stratification, and medication adherence will be essential to allow children with asthma to return safely to school.

Retrospective study identifies infection related risk factors in close contacts during COVID-19 epidemic

OBJECTIVES

This study aimed to compare the risk of infection of children with that of adults and to explore risk factors of infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) by following up close contacts of COVID-19 patients.

METHOD

The retrospective cohort study was performed among close contacts of index cases diagnosed with COVID-19 in Guangzhou, China. Demographic characteristics, clinical symptoms and exposure information were extracted. Logistic regression analysis was employed to explore the risk factors. The restricted cubic spline was conducted to examine to the dose-response relationship between age and SARS-CoV-2 infection.

RESULTS

The secondary attack rate (SAR) was 4.4% in 1,344 close contacts. The group of household contacts (17.2%) had the highest SAR. The rare-frequency contact (p < 0.001) and moderate-frequency contact (p < 0.001) were associated with lower risk of infection. Exposure to index cases with dry cough symptoms was associated with infection in close contacts (p = 0.004). Compared with children, adults had a significantly increased risk of infection (p = 0.014). There is a linear positive correlation between age and infection (p = 0.001).

CONCLUSIONS

Children are probably less susceptible to COVID-19. Close contacts with frequent contact with patients and those exposed to patients with cough symptoms are associated with an increased risk of infection.

Asymptomatic SARS Coronavirus 2 infection: Invisible yet invincible

While successful containment measures of COVID-19 in China and many European countries have led to flattened curves, case numbers are rising dramatically in other countries, with the emergence of a second wave expected. Asymptomatic individuals carrying SARS-CoV-2 are hidden drivers of the pandemic, and infectivity studies confirm the existence of transmission by asymptomatic individuals. The data addressed here show that characteristics of asymptomatic and presymptomatic infection are not identical. Younger age correlates strongly with asymptomatic and mild infections and children as hidden drivers. The estimated proportion of asymptomatic infections ranges from 18% to 81%. The current perception of asymptomatic infections does not provide clear guidance for public-health measures. Asymptomatic infections will be a key contributor in the spread of COVID-19. Asymptomatic cases should be reported in official COVID-19 statistics.