Combination Vaccines

Combination vaccines have been around since 1945 (trivalent influenza vaccine) and they combine either different serotypes of one microorganism (e.g., influenza or pneumococcal vaccines) or different microorganisms (e.g., DTP combinations). Potential chemical and physical interactions, unpredictable immunological interactions, and in one instance: increased AE, increasing likelihood of production failures, and reduced flexibility of a vaccination program are challenges for developing combination vaccines. With an increasing number of new vaccines for protecting the very young, DTaP- and DTwP-based combinations have become the cornerstone of pediatric vaccination programs around the globe since the mid-1990s. Live vaccine combinations include MR, MMR, and MMRV combinations as well as (trivalent) OPV. Combination vaccines for travelers include HAV-HBV combination and HAV-Ty vaccines. Dozens of diverse combination vaccine products are licensed today around the globe, some of them only in single countries to cover specific local needs. Combination vaccines have been shown to result in increased acceptance, completion and compliance with vaccination programs; in addition, they offer simplified logistics, reduce administration errors, reduce the number of medical visits and cost for the individual as well as for society, among other benefits.

Children develop robust and sustained cross-reactive spike-specific immune responses to SARS-CoV-2 infection

SARS-CoV-2 infection is generally mild or asymptomatic in children but a biological basis for this outcome is unclear. Here we compare antibody and cellular immunity in children (aged 3–11 years) and adults. Antibody responses against spike protein were high in children and seroconversion boosted responses against seasonal Beta-coronaviruses through cross-recognition of the S2 domain. Neutralization of viral variants was comparable between children and adults. Spike-specific T cell responses were more than twice as high in children and were also detected in many seronegative children, indicating pre-existing cross-reactive responses to seasonal coronaviruses. Importantly, children retained antibody and cellular responses 6 months after infection, whereas relative waning occurred in adults. Spike-specific responses were also broadly stable beyond 12 months. Therefore, children generate robust, cross-reactive and sustained immune responses to SARS-CoV-2 with focused specificity for the spike protein. These findings provide insight into the relative clinical protection that occurs in most children and might help to guide the design of pediatric vaccination regimens.

Vaccination programs for children aged up to 18 years in Europe, 2020

Although all European countries have vaccination policies for children, there are no comprehensive studies of pediatric vaccination programs in Europe. We studied vaccination programs for children in Europe. Vaccinations against diphtheria, tetanus, pertussis, poliomyelitis, Haemophilus influenzae type b, hepatitis B, measles, mumps, rubella, and influenza existed in 42 countries, against human papilloma virus in 41 countries, and against pneumococcus in 40 countries. In addition, the following vaccinations existed: against tuberculosis (35 countries), hepatitis A (33), meningococcus A, C, W, Y (30), rotavirus and varicella (28 countries each), meningococcus B (24), tick-born encephalitis (22), and meningococcus C (16). Mandatory vaccinations are implemented in 21 countries, mainly against diphtheria, tetanus, pertussis, poliomyelitis, H. influenzae type b, hepatitis B, measles, mumps, rubella, tuberculosis, and pneumococcus. There are significant differences among pediatric vaccination programs in Europe regarding number, schedules, indications, and regulatory frame (recommended or mandatory vaccinations). A consensus-based vaccination program for all children is needed.

Norovirus: Vaccine Challenges and Development

Noroviruses are a group of single-stranded RNA pathogens that cause acute gastroenteritis worldwide. Due to the high rates of mutation and evolution in the viruses, creating an effective vaccine to treat norovirus has been difficult. Factors such as the type of vaccine – live attenuated, subunit, or virus like particles – and target age group have limited progress in development. To better understand the best vaccine types and target groups for norovirus vaccine development, continuous research on the subjects will be encouraged. It will be shown that use of virus-like particles (VLPs) and a pediatric target group are the most effective options due to the versatility of VLPs and higher projected norovirus prevention rates for pediatric vaccination. The result of research will be useful to scientists creating norovirus vaccines and will help provide new perspectives for future research.

COVID-19 Vaccine Hesitancy among Parents of Children and Adolescents Living in Brazil

Background: The immunization of large portions of populations in low/middle-income countries is considered one of the key measures to limit the development of new SARS-CoV-2 variants. However, parental vaccine hesitancy might be an important obstacle to pediatric vaccination. The aim of this survey was to study the prevalence and extent of COVID-19 vaccine hesitancy among parents of children and adolescents living in Brazil. Methods: Caregivers of children and adolescents referred to the emergency department of Hospital Estadual de Bauru, São Paulo (Brazil) were invited to fill in a validated questionnaire on vaccine hesitancy and to report their willingness for themselves and their offspring to receive a COVID-19 vaccine. Results: A total of 501 consecutive caregivers filled in the survey. Response rate was 100%. A minority (N = 14, 2.8%) of caregivers were hesitant about vaccines. Despite this, half of them declared they were willing to vaccinate their offspring against COVID-19. Conclusions: This survey identifies that vaccine hesitancy is very low among caregivers living in Brazil and that even many of the hesitant caregivers are willing to vaccinate their offspring against COVID-19. This study highlights the importance of offering the COVID-19 vaccination to the whole population, including subjects that present uncertainty about other vaccines.

Awareness and acceptance of anticipated pediatric COVID-19 vaccination in rural South India

Background: The objective of this study was to assess the awareness and acceptance of anticipated COVID-19 pediatric vaccination among parents in rural south India.Methods: Objective questionnaire based online cross-sectional study in out-patient department, school WhatsApp groups and the community between 01 July 2021 to 15 July 2021. Sample size 873. Parents of children less than 18 years of age willing to participate in the study were included. Parents not willing to participate in the study were excluded.Results: 64.6% parents accepted pediatric COVID-19 vaccination; 96.4% felt it beneficial to vaccinate children prior to re-opening of school. 96.68% were positive that vaccination in children shall play a pivotal role in the projected third wave. 35.39% were hesitant and wanted to delay vaccinating their children and 14.14% do not believe in vaccine efficacy. 14.53% parents were weary of giving vaccine to their children due to personal experience of adverse effects they had suffered, and 22.45% parents refused vaccination due to hearsay adverse effects. 17.6% parents felt that post COVID-19 infection, children don’t need vaccination. 38.95% of parents were concerned about interaction of COVID-19 vaccine with other vaccines of immunisation schedule, 19.36% felt that children don’t need specific COVID-19 vaccine since the regular immunisation schedule prevents COVID-19 infection.Conclusions: Parents of rural India are aware of the pandemic and its lasting impact in our society but its effect on children is still beyond their comprehension. Most parents are willing and accept pediatric COVID-19 vaccination, however vaccine hesitancy and misconceptions are significant entities that can derail full coverage of children.