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The distribution of COVID-19 vaccines has proved to be a challenging task for public health authorities in many countries. Among several decisions involved in the task, allocating limited available vaccines to administration points is indeed critical. However, the operation management literature lacks evidence-based mathematical models that could support effective, efficient, sustainable and equitable vaccine allocation decision. This paper develops the fundamentals of a decision support system for COVID-19 vaccine allocation inside countries. The proposed DSS intends to support public health authorities in real-time by illustrating possible vaccine alternatives. The system could also inform and support other actors in the COVID19 distribution for planning and collaboration. Two illustrative cases for the COVID-19 vaccine allocation have been investigated to highlight potential benefits of our methodology.

The recent decline in vaccination rates across Europe has led to outbreaks of vaccine preventable diseases such as measles. Although there have always been persons opposed to vaccination, in recent years an increasing number of parents are losing confidence in or are being complacent about vaccinating their children. Given the accessibility of information on the internet, parents are actively and independently researching vaccines. They are exposed to negative claims about vaccines that appeal to their emotions and emotional stories tend make parents doubt vaccinations. By contrast, most positive vaccine messages focus on providing information through scientific data which has proven to be ineffective for some hesitant parents.Vaccine hesitancy can only be understood by looking at it from different perspectives and by exchanging knowledge between multiple fields of study. A transdisciplinary approach, in which individuals with different backgrounds search for solutions together, is necessary to be able to provide one or more solutions to the problem. Therefore, we spent eight months trying to solve part of this wicked problem from a transdisciplinary perspective. Based on literature reviews of different topics within vaccine hesitancy, interviews with hesitant parents, interactions with various stakeholders within and outside academia, and analyses of popular views on social media concerning vaccines, we question the effectiveness of the current pro-vaccine approaches. We also suggest adopting ‘storytelling’ that incorporates scientific data to inform parents and we argue that narratives are intrinsically persuasive as they are easier to understand and could prove more effective than traditional scientific communication. We expect that this strategy will contribute to the increase in and maintenance of high vaccination coverage rates and stop the circulation and outbreak of vaccine preventable diseases.

Background: Vaccination can protect against life-threatening infectious diseases. This is even more important for immunocompromised children because of their increased risk of complications upon exposure to vaccine-preventable diseases. We assessed vaccination coverage and seroprotection rate for measles, mumps and rubella (MMR) and diphtheria, tetanus and pertussis (DTP) in immunocompromised children in a university hospital in Flanders, Belgium.Methods: Antibody titers were determined by ELISA (MMR) and multiplex assay (DTP) patients with pediatric immunodeficiencies (n=88) and solid organ transplant recipients (n=35), aged 2-16 years. Titers were classified as seropositive if above cut-off value. Vaccination data were retrieved from documents provided by the parents and the general practitioner and verified against the Flemish vaccination register. Patients were considered fully vaccinated if they had been correctly vaccinated for their age according to the recommended Belgian immunisation programme. Results: Vaccination rates are lower compared to the general population of Flemish children. Moreover, as can be expected, seroprotection rates for all investigated diseases were lower in immunocompromised children compared to literature data on healthy children. However, vaccination is still associated with a better protection for measles, mumps, rubella and tetanus, but only for rubella statistical significance was reached. Seroprotection rates seemed slightly lower in the transplant group.Conclusion: Up to 50 % of immunocompromised children remain susceptible to vaccine preventable diseases. This can be explained by the nature of their disease, the immunosuppressive medication in SOT, and to the relatively low vaccination coverage (74 to 79%). These results highlight the importance of herd immunity and the need for better follow-up of the vaccination status in immunocompromised patients.

It is not yet clear to what extent SARS-CoV-2 infection rates in children reflect community transmission, nor whether infection rates differ between primary schoolchildren and young teenagers. A cross-sectional serosurvey compared the SARS-CoV2 attack-rate in a sample of 362 children recruited from September 21 to October 6, 2020, in primary (ages 6-12) or lower secondary school (ages 12-15) in a municipality with low community transmission (Pelt) to a municipality with high community transmission (Alken) in Belgium. Children were equally distributed over grades and regions. Blood samples were tested for the presence of antibodies to SARS-CoV-2 with an enzyme-linked immunosorbent assay. We found anti-SARS-CoV-2 antibodies in 4.4% of children in the low transmission region and in 14.4% of children in the high transmission region. None of the primary schoolchildren were seropositive in the low transmission region, whereas the seroprevalence among primary and secondary schoolchildren did not differ significantly in the high transmission region. None of the seropositive children suffered from severe disease. Children who were in contact with a confirmed case (RR 2.9; 95%CI 1.6-4.5), who participated in extracurricular activities (RR 5.6; 95%CI 1.2-25.3), or whose caregiver is a healthcare worker who had contact with COVID-19 patients (RR 2.2; 95%CI 1.0-4.6) were at higher risk of seropositivity. If SARS-CoV2 circulation in the community is high, this will be reflected in the pediatric population with similar infection rates in children aged 6-12 years and 12-15 years. What is Known: Children are generally less affected by COVID-19 than adults but SARS-CoV2 infection rates among children are not well known. There were large regional differences in infection rates during the first wave of the SARS-CoV2 pandemic. What is New: None of the primary schoolchildren (6-12 years) were seropositive for SARS-CoV2 in an area with a low community transmission, but infection rates were higher in adolescents (12-15 years). In an area with high community transmission, seroprevalence rates in younger children were more comparable to those in adolescents. Sciensano