Considering Mandatory Vaccination of Children for COVID-19

The impact of COVID-19 childhood and adolescent vaccination on mortality in Argentina

INTRODUCTION

Argentina authorized COVID-19 vaccination for adolescents 12 years and older in August 2021, and then for children three years and older in October 2021. Children aged 6 months-2 years received a two-dose regimen beginning July 2022.

OBJECTIVE

This study aims to analyze the impact of COVID-19 vaccination among children aged 0-17, considering vaccination status and mortality for the 2020-2022 period.

METHODS

We conducted a population-level analysis examining all-cause mortality, COVID-19 cases, deaths, and vaccination records. We compared outcomes with child mortality for diseases for which vaccination is compulsory, before and after each vaccine rollout.

RESULTS

A decrease in COVID-19-related deaths was observed in 2022 for pediatric age groups (3-11 and 12-17) with relatively higher vaccination coverage. However, no decrease was observed for the 0-2 year old age group, which had the longest delay in access to immunization and lowest vaccination coverage. When compared to unvaccinated populations in 2022, we observe an 8-15-fold reduction in cumulative death rates for pediatric populations vaccinated with 1 or more doses, and a 16-18-fold reduction for those vaccinated with 2 or more doses. Historical analysis shows that for diseases for which vaccination is now compulsory in many countries, pre-vaccine-rollout mortality was lower than COVID-19 deaths during 2020-2022.

CONCLUSIONS AND RELEVANCE

SARS-CoV-2 immunization was associated with reduced COVID-19 deaths for children and adolescents in Argentina. Our findings suggest that greater efforts should be undertaken to ensure wider COVID-19 vaccine coverage in children and adolescents, especially infants.

Factors influencing parental COVID-19 vaccination willingness for children in Japan

Objectives

This study aims to investigate the factors influencing parental willingness in COVID-19 vaccination for children in Japan in light of the introduction of pediatric vaccines.

Methods

An online survey was conducted in February 2022, coinciding with the imminent start of pediatric COVID-19 vaccinations in Japan. It assessed attitudes toward vaccine uptake and included questions about health-related attributes, psychological considerations, and sources of COVID-19 information. Data from 2,419 respondents who had children under the age of 12 were analyzed using multinomial logistic regression to identify factors associated with parental willingness towards COVID-19 vaccination for children. The outcomes were "agree" (in favor of vaccination), "not sure" (undecided), with "disagree" (against vaccination) as the reference category.

Results

Among participants supportive of vaccination ("agree" compared to the "disagree" reference), salient determinants included: gender (Men in reference to women: odds ratio [OR] 1.54; 95 % confidence interval [CI] 1.11-2.15), highest educational level (Junior College/Vocational in reference to under high school: OR 0.61; 95 % CI 0.40-0.93, Bachelor's /Master's/Doctoral degree in reference to under high school: OR 0.59; 95 % CI 0.42-0.84), perception of benefits of COVID-19 vaccination (Significant in reference to Insignificant: OR 2.04; 95 % CI 1.26-3.28), perception of risks of COVID-19 vaccination (Significant in reference to Insignificant: OR 0.28; 95 % CI 0.19-0.42, Neutral in reference to Insignificant: OR 0.48; 95 % CI 0.33-0.71), the number of referenced information sources utilized for COVID-19 was associated with attitudes towards children's vaccination (OR 1.02; 95 % CI 1.00-1.04).

Conclusion

The study highlights the multifaceted factors influencing parents' COVID-19 vaccination attitudes for their children, encompassing socioeconomic, health, psychological, and informational aspects. Factors like cautious information gathering, vaccine concerns and diverse referenced information sources impact willingness. To facilitate informed decision-making, essential measures include government risk communication, widespread vaccine information dissemination, and enhancing parents' health information accessibility and evaluation skills are important.

Transmission risks of Omicron BA.5 following inactivated COVID-19 vaccines among children and adolescents in China

BACKGROUND

As SARS-CoV-2 Omicron variants circulating globally since 2022, assessing the transmission characteristics, and the protection of vaccines against emerging Omicron variants among children and adolescents are needed for guiding the control and vaccination policies.

METHODS

We conducted a retrospective cohort study for SARS-CoV-2 infections and close contacts aged <18 years from an outbreak seeded by Omicron BA.5 variants. The secondary attack rate (SAR) was calculated and the protective effects of two doses of inactivated vaccine (mainly Sinopharm /BBIBP-CorV) within a year versus one dose or two doses above a year after vaccination against the transmission and infection of Omicron BA.5 were estimated.

RESULTS

A total of 3442 all-age close contacts of 122 confirmed SARS-CoV-2 infections aged 0-17 years were included. The SAR was higher in the household setting and for individuals who received a one-dose inactivated vaccine or those who received a two-dose for more than one year, with estimates of 28.5% (95% credible interval [CrI]: 21.1, 37.7) and 55.3% (95% CrI: 24.4, 84.8), respectively. The second dose of inactivated vaccine conferred substantial protection against all infection and transmission of Omicron BA.5 variants within a year.

CONCLUSIONS

Our findings support the rollout of the second dose of inactivated vaccine for children and adolescents during the Omciron BA.5 predominant epidemic phase. Given the continuous emergence of SARS-CoV-2 variants, monitoring the transmission risk and corresponding vaccine effectiveness against SARS-CoV-2 variants among children and adolescents is important to inform control strategy.

Are parents' willing to vaccinate their children against COVID-19? A qualitative study based on the Health Belief Model

In response to the COVID-19 pandemic, several countries have started implementing voluntary or involuntary mass vaccination programs. Although vaccine acceptance is high among adults, uncertainty about whether to vaccinate children against COVID-19 remains a controversial theme. To date, few qualitative studies have explored parents' views on this topic. A qualitative descriptive study design was used to collect data and individual in-depth interviews were conducted with 50 parents in the Makkah region of Saudi Arabia. The Health Belief Model (HBM) was used as a guide in developing the interview guide. Each question was related to a construct of the HBM. The data were then analyzed using thematic content analysis and interpreted using NVivo software. Two major themes emerged: motivation to vaccinate children, which was influenced by perceived benefits, perceived severity, perceived suitability, collective responsibilities, confidence, and cues to action; and barriers to vaccination in children, which included complacency, rapid vaccine development, and uncertainty about the long-term side effects of the vaccine. The findings of this study revealed that the public is not sufficiently informed about the efficacy or side effects of the COVID-19 vaccine, increasing the awareness of which will help parents make informed decisions regarding vaccinating their children and potentially increase vaccine acceptance.

Healthcare provider perspectives on COVID-19 vaccination for children in India

BACKGROUND

The rapid development and deployment of effective COVID-19 vaccines have been critical to halt the spread of the pandemic. India started vaccinating children in early 2022, however, vaccine uptake has been suboptimal.

METHODS

Between September and November 2022, we conducted an online survey that was disseminated to eligible participants via email, text messages and social media platforms across India. The survey aimed to gather the perspectives of Indian healthcare providers regarding key factors related to the rollout of paediatric COVID-19 vaccines. Descriptive statistics were used to analyse participant demographics and responses on knowledge about paediatric COVID-19 vaccines, perceived risks and benefits, and vaccine rollout strategies.

RESULTS

The survey yielded 805 respondents from 23 Indian states; 63.5% were men, 97.3% were paediatricians, median age was 44 years (IQR 25-81). Eighty-one per cent and 65.2% respondents had heard about the most common paediatric COVID-19 vaccines in India, Covaxin and Corbevax, but only 52.9%, 53.7% and 62.1% felt adequately informed about their safety, efficacy and vaccination schedules, respectively. Thirty per cent of respondents were unaware of vaccination guidelines. Eighty-five per cent of respondents felt that vaccines would reduce the incidence of severe disease, hospitalisation and deaths, and 60.6% felt children with comorbidities should be prioritised for vaccination. Perceived supply side barriers included lack of enforcement of guidelines (45.2%) and adverse effects following immunisation monitoring systems (37.6%), and on the demand side, parental vaccine hesitancy (64.4%). Eighty-one per cent believed that school-based vaccination strategies would be highly effective in increasing uptake.

CONCLUSIONS

Most respondents were in support of the COVID-19 paediatric vaccination, although just over half did not feel adequately informed. Concerns about vaccine hesitancy among caregivers were the leading reported barrier. Targeted interventions are needed to provide adequate knowledge support to healthcare providers and evidence-based public health messaging to reduce vaccine hesitancy among caregivers.

Immunogenicity and safety assessment of a SARS-CoV-2 recombinant spike RBD protein vaccine (Abdala) in paediatric ages 3-18 years old: a double-blinded, multicentre, randomised, phase 1/2 clinical trial (ISMAELILLO study)

Background

COVID-19 in paediatric ages could result in hospitalizations and death. In addition, excluding children from vaccination could turn them into reservoirs of the SARS-COV-2. Safe and effective COVID-19 vaccines are urgently needed for large-scale paediatric vaccination. ISMAELILLO study aimed to evaluate safety and immunogenicity of two strengths of a new recombinant receptor-binding domain (RBD) protein vaccine (Abdala) in paediatric population.

Methods

A double-blinded, multicentre, randomised, phase 1/2 clinical trial was conducted in nine polyclinics in the province of Camagüey, Cuba. Healthy children and adolescents were stratified according to age (3-11 years old, or 12-18 years old) and they were randomly assigned (1:1; block size four) in two dosage level groups of vaccine to receive three intramuscular doses of 25 μg or 50 μg of RBD, 14 days apart. Main safety endpoint was analyzed as the percentage of serious adverse reactions during vaccination up to 28 days after the third dose (Day 56) in participants who received at least one dose vaccination. The primary immunogenicity endpoint assessed was seroconversion rate of anti-RBD IgG antibody at day 56. The immunogenicity outcomes were assessed in the per-protocol population. This trial is registered with Cuban Public Registry of Clinical Trials, RPCEC00000381.

Findings

Between July 15, 2021, and August 16, 2021, 644 paediatric subjects were screened, of whom 592 were enrolled after verifying that they met the selection criteria: firstly 88 were included in Phase 1 of the study and 504 who completed Phase 2. The vaccine was well tolerated. Injection site pain was the most frequently reported local event (143 [8·4%] of 1707 total doses applied), taking place in 66/851 (7·8%) in the 25 μg group and in 77/856 (9·0%) in the 50 μg. The most common systemic adverse event (AE) was headache: 23/851 (2·7%) in the 25 μg group and 19/856 (2·2%) in the 50 μg. Reactogenicity was mild or moderate in severity, represented in 75% of cases by local symptoms, completely resolved in the first 24-48 h. Twenty-eight days after the third dose, seroconversion anti-RBD IgG were observed in 98·2% of the children and adolescents (231/234) for the 50 μg group and 98·7% (224/228) for the 25 μg group without differences between both strength. The specific IgG antibody geometric mean titres (GMT) showed higher titres between participants who received Abdala 50 μg (231·3; 95% CI 222·6-240·4) compared to those who received 25 μg (126·7; 95% CI 121·9-131·7). The mean ACE2 inhibition %, were 59·4% for 25 μg, and for 50 μg, 72·9% (p < 0·01). Both strength elicited neutralising activity against the SARS-CoV-2, specifically (18·3; 95% CI 14·7-22·78) for Abdala 25 μg and (36·4; 95% CI 30·26-43·8) for 50 μg to the selected sample analyzed.

Interpretation

Abdala vaccine was safe and well tolerated at both antigenic strength levels tested in participants aged between 3 and 18 years. Regarding immunogenicity, Abdala Vaccine stimulated the production of specific IgG antibodies against the RBD of SARS-CoV-2 as well as the production of ACE2 inhibition titres and neutralising antibodies (Nab) in children and adolescents.

Funding

Centre for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba.

What are the key pediatric public policy priorities as the COVID-19 pandemic persists?

The COVID-19 pandemic is not over, and its impact is just beginning to be felt on children. COVID-19 vaccines protect both the pregnant patient and newborns, and breastfeeding provides a key component of passive protective immunity. "Long COVID" has contributed to the current crisis in pediatric mental health, and vaccines confer protection against this long-term complication of COVID-19 disease. Vaccine misinformation is not only impacting compliance with maternal and pediatric COVID-19 immunization efforts, but also other routine childhood vaccinations. As a public health priority, we must improve our response to vaccine misinformation and find novel strategies to improve vaccine compliance.

Molecular Determinants of the Early Life Immune Response to COVID-19 Infection and Immunization

Clinical manifestations from primary COVID infection in children are generally less severe as compared to adults, and severe pediatric cases occur predominantly in children with underlying medical conditions. However, despite the lower incidence of disease severity, the burden of COVID-19 in children is not negligible. Throughout the course of the pandemic, the case incidence in children has substantially increased, with estimated cumulative rates of SARS-CoV-2 infection and COVID-19 symptomatic illness in children comparable to those in adults. Vaccination is a key approach to enhance immunogenicity and protection against SARS-CoV-2. Although the immune system of children is functionally distinct from that of other age groups, vaccine development specific for the pediatric population has mostly been limited to dose-titration of formulations that were developed primarily for adults. In this review, we summarize the literature pertaining to age-specific differences in COVID-19 pathogenesis and clinical manifestation. In addition, we review molecular distinctions in how the early life immune system responds to infection and vaccination. Finally, we discuss recent advances in development of pediatric COVID-19 vaccines and provide future directions for basic and translational research in this area.

The Role of Immunity in the Pathogenesis of SARS-CoV-2 Infection and in the Protection Generated by COVID-19 Vaccines in Different Age Groups

This study aims to review the available data regarding the central role of immunity in combating SARS-CoV-2 infection and in the generation of protection by vaccination against COVID-19 in different age groups. Physiologically, the immune response and the components involved in it are variable, both functionally and quantitatively, in neonates, infants, children, adolescents, and adults. These immunological differences are mirrored during COVID-19 infection and in the post-vaccination period. The outcome of SARS-CoV-2 infection is greatly dependent on the reaction orchestrated by the immune system. This is clearly obvious in relation to the clinical status of COVID-19 infection, which can be symptomless, mild, moderate, or severe. Even the complications of the disease show a proportional pattern in relation to the immune response. On the contrary, the commonly used anti-COVID-19 vaccines generate protective humoral and cellular immunity. The magnitude of this immunity and the components involved in it are discussed in detail. Furthermore, many of the adverse effects of these vaccines can be explained on the basis of immune reactions against the different components of the vaccines. Regarding the appropriate choice of vaccine for different age groups, many factors have to be considered. This is a cornerstone, particularly in the following age groups: 1 day to 5 years, 6 to 11 years, and 12 to 17 years. Many factors are involved in deciding the route, doses, and schedule of vaccination for children. Another important issue in this dilemma is the hesitancy of families in making the decision about whether to vaccinate their children. Added to these difficulties is the choice by health authorities and governments concerning whether to make children's vaccination compulsory. In this respect, although rare and limited, adverse effects of vaccines in children have been detected, some of which, unfortunately, have been serious or even fatal. However, to achieve comprehensive control over COVID-19 in communities, both children and adults have to be vaccinated, as the former group represents a reservoir for viral transmission. The understanding of the various immunological mechanisms involved in SARS-CoV-2 infection and in the preparation and application of its vaccines has given the sciences a great opportunity to further deepen and expand immunological knowledge. This will hopefully be reflected positively on other diseases through gaining an immunological background that may aid in diagnosis and therapy. Humanity is still in continuous conflict with SARS-CoV-2 infection and will be for a while, but the future is expected to be in favor of the prevention and control of this disease.

A "step too far" or "perfect sense"? A qualitative study of British adults' views on mandating COVID-19 vaccination and vaccine passports

BACKGROUND

Debate is ongoing about mandating COVID-19 vaccination to maximise uptake. Policymakers must consider whether to mandate, for how long, and in which contexts, taking into account not only legal and ethical questions but also public opinion. Implementing mandates among populations who oppose them could be counterproductive.

METHODS

Qualitative telephone interviews (Feb-May 2021) with British adults explored views on vaccine passports and mandatory vaccination. Participants (n = 50) were purposively selected from respondents to a probability-based national survey of attitudes to COVID-19 vaccination, to include those expressing vaccine-hesitancy. Data were analysed thematically.

FINDINGS

Six themes were identified in participants' narratives concerning mandates: (i) mandates are a necessary and proportionate response for some occupations to protect the vulnerable and facilitate the resumption of free movement; (ii) mandates undermine autonomy and choice; (iii) mandates represent an over-reach of state power; (iv) mandates could potentially create 'vaccine apartheid'; (v) the importance of context and framing; and (vi) mandates present considerable feasibility challenges. Those refusing vaccination tended to argue strongly against mandates. However, those in favour of vaccination also expressed concerns about freedom of choice, state coercion and social divisiveness.

DISCUSSION

To our knowledge, this is the first in-depth UK study of public views on COVID-19 vaccine mandates. It does not assess support for different mandates but explores emotions, principles and reasoning underpinning views. Our data suggest that debate around mandates can arouse strong concerns and could entrench scepticism. Policymakers should proceed with caution. While surveys can provide snapshots of opinion on mandates, views are complex and further consultation is needed regarding specific scenarios.

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.

Safety after BBIBP-CorV (Sinopharm) COVID-19 Vaccine in Adolescents Aged 10-17 Years in Thailand

Coronavirus disease 2019 affected child health and impacted learning because of the resulting onsite school closures. This prospective cohort study included children aged 10-17 who received two 4 µg doses of BBIBP-CorV administered intramuscularly 21-28 days apart. To assess vaccine safety, 36,808 participants were then followed with paper- and web-based online questionnaire surveys that captured local and systemic reactogenicities following vaccine administration on days 1, 7, and 30. Among participants, 76% (27,880) reported reactogenicity within the first 24 h and 7 days following the first dose. Half (51.41%) of participants experienced pain at the injection site; the majority of cases were mild in severity. Injection site tenderness (37.93%) was another common local reaction. Fatigue (37.89%), myalgia (33.56%), and headache (26.76%) were the most common systemic reactions. On days 2-7 after the first dose, 25.85% of participants experienced adverse reactions. Following the second dose, reactogenicity was 7.6% and 1.09% within 24 h and between days 2-7. The majority of reactions were of mild to moderate severity. We report that two doses of the BBIBP-CorV caused mild to moderate side effects in adolescents in Thailand. The findings confirm the vaccine's safety profile in this age group.

Effectiveness of BBIBP-CorV, BNT162b2 and mRNA-1273 vaccines against hospitalisations among children and adolescents during the Omicron outbreak in Argentina: A retrospective cohort study

Background

Although paediatric clinical presentations of COVID-19 are usually less severe than in adults, serious illness and death have occurred. Many countries started the vaccination rollout of children in 2021; still, information about effectiveness in the real-world setting is scarce. The aim of our study was to evaluate vaccine effectiveness (VE) against COVID-19-associated-hospitalisations in the 3–17-year population during the Omicron outbreak.

Methods

We conducted a retrospective cohort study including individuals aged 3–17 registered in the online vaccination system of the Buenos Aires Province, Argentina. mRNA-1273 and BNT162b2 were administered to 12–17-year subjects; and BBIBP-CorV to 3–11-year subjects. Vaccinated group had received a two-dose scheme by 12/1/2021. Unvaccinated group did not receive any COVID-19 vaccine between 12/14/2021 and 3/9/2022, which was the entire monitoring period. Vaccine effectiveness (VE) against COVID-19-associated hospitalisations was calculated as (1-OR)x100.

Findings

By 12/1/2021, 1,536,435 individuals aged 3–17 who had received zero or two doses of SARS-CoV-2 vaccines were included in this study. Of the latter, 1,440,389 were vaccinated and 96,046 not vaccinated. VE were 78.0%[68.7–84.2], 76.4%[62.9–84.5] and 80.0%[64.3–88.0] for the entire cohort, 3–11-year (BBIBP-CorV) subgroup and 12–17 (mRNA vaccines) subgroup, respectively. VE for the entire population was 82.7% during the period of Delta and Omicron overlapping circulation and decreased to 67.7% when Omicron was the only variant present.

Interpretation

This report provides evidence of high vaccine protection against associated hospitalisations in the paediatric population during the Omicron outbreak but suggests a decrease of protection when Omicron became predominant. Application of a booster dose in children aged 3–11-year warrants further consideration.

Funding

None.

Acceptability of COVID-19 vaccine mandates among New York City parents, November 2021

School-based vaccine mandates improve vaccination coverage in children. We conducted a cross-sectional survey of parents in New York City (NYC) in November 2021 to measure acceptability of COVID-19 vaccine mandates for students, and for teachers and school staff. Random address-based sampling was used to recruit parents of children 5-11 years of age. Among 2,506 parents surveyed, 44.3% supported school-based vaccine mandates for students and 69.1% supported mandates for teachers and school staff. Asian parents, male parents, those with higher income, college education, those voting for the 2021 Democratic mayoral candidate and parents from Manhattan were most likely to support vaccine mandates for students. Among all parents, 25.1% said they would not vaccinate their child if required. Our data show only modest support for school-based COVID-19 vaccine mandates for children despite their importance in improving vaccination coverage.

Pediatric Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Vaccines: Perceptions and Attitudes From the Food and Drug Administration Public Commentary

Authorization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines for children has ushered in a new phase of the immunization campaign to address the pandemic but has been received with mixed responses from parents, children, and opinion leaders. Herein we consider perceptions and attitudes towards pediatric SARS-CoV-2 vaccines from a Food and Drug Administration (FDA) public commentary reflecting more than 63 000 comments.

Adolescent COVID-19 Vaccine Decision-Making among Parents in Southern California

Adolescent COVID-19 vaccination has stalled at 53% in the United States. Vaccinating adolescents remains critical to preventing the continued transmission of COVID-19, the emergence of variants, and rare but serious disease in children, and it is the best preventive measure available to return to in-person schooling. We investigated parent–adolescent COVID-19 vaccine decision-making. Between 24 February and 15 March 2021, we conducted surveys and 12 focus groups with 46 parent–adolescent dyads in Southern California. Parents and adolescents completed a survey prior to participation in a focus group discussion, which focused on exploring COVID-19 vaccine acceptance or uncertainty and was guided by the 5C vaccine hesitancy model. Parents uncertain about vaccinating adolescents expressed low vaccine confidence and high COVID-19 disease risk complacency. Parents who accepted COVID-19 vaccination for adolescents expressed high confidence in health authority vaccine recommendations, high perceived COVID-19 risk, and collective responsibility to vaccinate children. Additionally, unique pandemic-related factors of vaccine acceptance included vaccinating for emotional health, resuming social activities, and vaccine mandates. Among parents, 46% were willing to vaccinate their adolescent, 11% were not, and 43% were unsure. Among adolescents, 63% were willing to vaccinate. Despite vaccine availability, 47% of adolescents remain unvaccinated against COVID-19. Factors associated with vaccine uncertainty and acceptability inform health care practitioner, school, community, and public health messaging to reach parents and adolescents.

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.

Associação entre letramento em saúde, ameaça pela COVID-19 e intenção vacinal de adolescentes brasileiros

Resumo Objetivo: investigar a influência do letramento em saúde na avaliação da ameaça à saúde pela COVID-19 e sobre a intenção de não se vacinar de adolescentes brasileiros. Método: estudo transversal com 526 adolescentes brasileiros de 14 a 19 anos. Aspectos socioeconômicos, perfil saúde-doença, letramento em saúde, ameaça à saúde pela COVID-19 e intenção de não se vacinar foram analisados por associação bivariada e regressão linear múltipla com resposta Poisson. Resultados: maior pontuação de letramento em saúde (p=0,010), doença cardíaca (p=0,006), menor renda (p=0,000) e morar na região norte (p=0,007) foram fatores que contribuíram para o sentimento de maior ameaça pela COVID-19. O letramento em saúde não influenciou a intenção de não se vacinar (p=0,091), cuja prevalência foi menor entre os adolescentes do Sudeste quando comparados aos do Norte (p=0,010), entre os que cursavam o ensino superior (p=0,049) e entre aqueles com maior renda (p=0,000). Conclusão: letramento em saúde influenciou a percepção da ameaça da doença, mas não a intenção de não se vacinar. Avaliação da ameaça à saúde pela COVID-19 e a prevalência da intenção de não se vacinar foram influenciadas pela região de residência, renda e escolaridade, o que reforça a importância dos determinantes sociais da saúde nesse contexto.

Relación entre alfabetización en salud, amenaza por COVID-19 e intención de vacunación entre los adolescentes brasileños

Resumen Objetivo: investigar la influencia de la alfabetización en salud sobre la evaluación de la amenaza por COVID-19 y sobre la intención de los adolescentes brasileños de no vacunarse. Método: estudio transversal con 526 adolescentes brasileños entre 14 y 19 años. Se analizaron aspectos socioeconómicos, perfil epidemiológico, alfabetización en salud, amenaza a la salud por COVID-19 y la intención de no vacunarse mediante una relación bivariada y regresión lineal múltiple de respuesta de Poisson. Resultados: una elevada puntuación de alfabetización en salud (p=0,010), enfermedades cardiovasculares (p=0,006), menor nivel de renta (p=0,000) y vivir en la región norte (p=0,007) fueron factores que ayudaron a la sensación de mayor amenaza por COVID-19. La alfabetización en salud no influyó en la intención de no vacunarse (p=0,091), cuya prevalencia fue más baja entre los adolescentes del Sudeste en comparación con los del Norte (p=0,010), entre los que cursaban estudios superiores (p=0,049) y mayor nivel de renta (p=0,000). Conclusión: la alfabetización en salud influyó sobre la percepción de la amenaza de la enfermedad pero no en la intención de no vacunarse. La evaluación de la amenaza a la salud por COVID-19 y la prevalencia de la intención de no vacunarse fueron condicionadas por la región de residencia, nivel de renta y educación, acentuando la importancia de los determinantes sociales de la salud en este contexto.

Association of health literacy, COVID-19 threat, and vaccination intention among Brazilian adolescents

Objective:

investigate the influence of health literacy on the assessment of COVID-19 threat to health and the intention not to be vaccinated among Brazilian adolescents.

Method:

cross-sectional study with 526 Brazilian adolescents aged 14 to 19 years. Socioeconomic aspects, health-disease profile, health literacy, health threat by COVID-19 and intention not to be vaccinated were analyzed by bivariate association and multiple linear regression with Poisson response.

Results:

higher health literacy score (p=0.010), cardiovascular disease (p=0.006), lower income (p=0.000), and living in the North region (p=0.007) were factors that contributed to feeling more threatened by COVID-19. Health literacy did not influence the intention not to be vaccinated (p=0.091), whose prevalence was lower among adolescents in the Southeast region when compared to those in the North region (p=0.010), among those who attended higher education (p=0,049) and those with higher income (p=0.000).

Conclusion:

health literacy influenced the perception of COVID-19 threat, but not the intention not to be vaccinated. Assessment of COVID-19 threat to health and prevalence of the intention not to be vaccinated were influenced by the region of residence, income, and education, which reinforces the importance of social determinants of health in this context.

Assessing Acceptability of COVID-19 Vaccine Booster Dose among Adult Americans: A Cross-Sectional Study

Given the emergence of breakthrough infections, new variants, and concerns of waning immunity from the primary COVID-19 vaccines, booster shots emerged as a viable option to shore-up protection against COVID-19. Following the recent authorization of vaccine boosters among vulnerable Americans, this study aims to assess COVID-19 vaccine booster hesitancy and its associated factors in a nationally representative sample. A web-based 48-item psychometric valid survey was used to measure vaccine literacy, vaccine confidence, trust, and general attitudes towards vaccines. Data were analyzed through Chi-square (with a post hoc contingency table analysis) and independent-sample t-/Welch tests. Among 2138 participants, nearly 62% intended to take booster doses and the remaining were COVID-19 vaccine booster hesitant. The vaccine-booster-hesitant group was more likely to be unvaccinated (62.6% vs. 12.9%) and did not intend to have their children vaccinated (86.1% vs. 27.5%) compared to their non-hesitant counterparts. A significantly higher proportion of booster dose hesitant individuals had very little to no trust in the COVID-19 vaccine information given by public health/government agencies (55% vs. 12%) compared to non-hesitant ones. The mean scores of vaccine confidence index and vaccine literacy were lower among the hesitant group compared to the non-hesitant group. Compared to the non-hesitant group, vaccine hesitant participants were single or never married (41.8% vs. 28.7%), less educated, and living in a southern region of the nation (40.9% vs. 33.3%). These findings underscore the need of developing effective communication strategies emphasizing vaccine science in ways that are accessible to individuals with lower levels of education and vaccine literacy to increase vaccination uptake.

Anti-COVID Vaccination for Adolescents: A Survey on Determinants of Vaccine Parental Hesitancy

Vaccine hesitancy has been considered one of the most severe threats to global health, as it represents an obstacle to achieving adequate vaccination coverage. Recent research studies aimed at investigating the propensity for anti-COVID vaccination among adults have found a high prevalence of vaccine hesitancy, but few data are available on parental vaccine hesitancy. We therefore built an anonymous online survey to investigate the factors related to the vaccine hesitancy of parents of adolescents between 12 and 17 years of age, with a special focus on demographic factors and the domains of confidence and complacency. The online survey was conducted by using the Crowd Signal platform from 15 July to 16 August 2021, in Italy. A total of 1799 analyzable questionnaires were analyzed. Overall, Favorable and Doubtful parents declared a higher level of confidence on safety and efficacy of pediatric vaccines and on confidence in health institutions than Hesitant/Reluctant ones (p-values < 0.001). The univariate multinomial logistic regression analysis and the multivariate multinomial logistic regression analysis showed that the Hesitant/Reluctant parents were younger than 40 years of age, with a secondary-school or three-year degree, free-lance, with a family income below €28,000, with an erroneous perception of the risk of COVID-19 as disease and with fear of anti-COVID vaccination. These results, which should be confirmed in a larger population and in different geographical areas, should lead Institutions and stakeholders to identify targeted communication tools to improve trust in health institutions, especially by younger parents.

Prevalence and Factors Associated with Parents' Non-Intention to Vaccinate Their Children and Adolescents against COVID-19 in Latin America and the Caribbean

We aimed to estimate the prevalence and factors associated with parents' non-intention to vaccinate their children and adolescents against COVID-19 in Latin America and the Caribbean (LAC). We performed a secondary analysis using a database generated by the University of Maryland and Facebook (Facebook, Inc., Menlo Park, CA, USA). We included adult (18 and over) Facebook users residing in LAC who responded to the survey between 20 May 2021 and 14 July 2021. We included sociodemographic characteristics, comorbidities, mental health, economic and food insecurity, compliance with mitigation strategies against COVID-19, and practices related to vaccination against this disease. We estimated the crude (cPR) and adjusted (aPR) prevalence ratios with their respective 95%CI. We analyzed a sample of 227,740 adults from 20 LAC countries. The prevalence of parents' non-intention to vaccinate their children and adolescents against COVID-19 was 7.8% (n = 15,196). An age above 35 years old, educational level above college, compliance with physical distancing, use of masks, having economic insecurity, having had COVID-19, anxiety symptoms, depressive symptoms, having a chronic condition or two or more comorbidities, and being vaccinated were associated with a lower prevalence of non-intention to vaccinate children and adolescents against COVID-19. Living in a town, a village, or a rural area was associated with a higher prevalence of non-intention to vaccinate children and adolescents against COVID-19. Approximately nine out of ten parents in LAC intended to vaccinate their children and adolescents against COVID-19. Our results allow for understanding parents' intentions to vaccinate children and adolescents and help promote and develop education strategies for national vaccination plans against COVID-19.

Parents' hesitation about getting their children vaccinated against COVID-19 in Japan

Given the urgent global need for vaccinating individuals of all ages against the COVID-19 pandemic, understanding the extent and reasons for parents' willingness to get their children vaccinated is important. This study used an internet-based questionnaire survey to determine parents' willingness to get their children (0 to 15 years) vaccinated in Japan and was conducted in April 2021 before COVID-19 vaccination for children began. Socio-demographic information, information about parents' willingness to get children vaccinated, reasons for their responses, and parents' willingness to get themselves vaccinated were obtained. Descriptive statistics were used to evaluate parents' willingness to get children vaccinated based on the other variables. Logistic regression analyses were conducted to identify the characteristics of parents who indicated willingness to get their children vaccinated and to identify the reasons for vaccine willingness. Of the 1100 respondents, 472 were willing to get children vaccinated, 470 were not sure, and 158 did not want to get children vaccinated. Considerable differences were found in the willingness to get children vaccinated across gender, age groups, occupation, annual income, respondent's academic background, and respondent's willingness to get COVID-19 vaccination for themselves. Reasons for being unsure about the vaccination included the vaccine's potential side effects (84.9%), uncertainty about vaccine safety (54.7%), and not trusting vaccine efficiency (25.7%). Parents' willingness to get the COVID-19 vaccine for themselves was a significant factor for their willingness to get children vaccinated after adjusting all other factors. The study recommends disseminating more and correct information to the public to increase vaccine willingness.

COVID-19 Vaccinations: A Comprehensive Review of Their Safety and Efficacy in Special Populations

COVID-19 has been spreading worldwide since late 2019. There is no definitive cure to date. Global vaccination programs are urgently required to confer herd immunity, reducing the incidence of COVID-19 infections and associated morbidity and mortality. However, a significant proportion of special populations are hesitant to receive vaccination due to their special conditions, namely, age (pediatrics and geriatrics), immunocompromised state, autoimmune diseases, chronic cardiovascular and pulmonary conditions, active or treated cancers, and pregnancy. This review aims to evaluate the existing evidence of COVID-19 vaccinations on these special populations and to provide clues to guide vaccination decision making to balance the benefits and risks of vaccinations.

Pediatric COVID-19: Immunopathogenesis, Transmission and Prevention

Children are unique in the context of the COVID-19 pandemic. Overall, SARS-CoV-2 has a lower medical impact in children as compared to adults. A higher proportion of children than adults remain asymptomatic following SARS-CoV-2 infection and severe disease and death are also less common. This relative resistance contrasts with the high susceptibility of children to other respiratory tract infections. The mechanisms involved remain incompletely understood but could include the rapid development of a robust innate immune response. On the other hand, children develop a unique and severe complication, named multisystem inflammatory syndrome in children, several weeks after the onset of symptoms. Although children play an important role in the transmission of many pathogens, their contribution to the transmission of SARS-CoV-2 appears lower than that of adults. These unique aspects of COVID-19 in children must be considered in the benefit-risk analysis of vaccination. Several COVID-19 vaccines have been authorized for emergency use in adolescents and clinical studies are ongoing in children. As the vaccination of adolescents is rolled out in several countries, we shall learn about the impact of this strategy on the health of children and on transmission within communities.