Introduktion: Humant papillomvirus, HPV, är världens vanligaste sexuellt överförbara infektion. De flesta HPV-infektioner läker ut av sig själva men de kan också bli kroniska och på sikt leda till cellförändringar och cancer. Sedan 2012 erbjuds alla flickor i Sverige vaccination mot HPV för att förhindra livmoderhalscancer, som är den vanligaste HPV-relaterade cancerformen. Vaccinationen utförs av skolsköterskor i årskurs 5-6. Vaccinationstäckningen för HPV-vaccination är dock lägre än för övriga vaccinationer i det svenska barnvaccinationsprogrammet. Skolsköterskorna har en viktig roll när det gäller att bemöta tveksamma vårdnadshavare och att få upp vaccinationstäckningen för att på sikt minska antalet cancerfall orsakade av HPV. Syftet med studien var att beskriva hur skolsköterskor i Halland agerar när vårdnadshavare tackar nej till HPV-vaccination för flickor i årskurs 5-6 och vad de upplever är anledningen till nekande. Metoden som valdes var en webbaserad enkätundersökning bland skolsköterskor på mellanstadieskolor i de sex halländska kommunerna. Enkäten skickades ut till 101 respondenter. Svarsfrekvensen var 56 procent och resultatet visade att skolsköterskorna i Halland inte agerar alls när vårdnadshavare tackar nej till HPV-vaccination för flickor i årskurs 5-6. Det främsta motivet till detta är att skolsköterskorna erbjuder nytt vaccinationstillfälle i senare årskurser. Skolsköterskornas uppfattning är att desinformation på internet, rädsla för biverkningar och flickornas ringa ålder utgör de vanligaste anledningarna för vårdnadshavare att tacka nej. Slutsats:Fortsatt arbete för att stärka skolsköterskorna i sin roll som vaccinationsförespråkare är nödvändig för att öka vaccinationstäckningen för HPV. / Introduction: Human papillomavirus, HPV, is the most common sexually transmitted infection. Most HPV infections disappear without intervention but HPV infection can also become chronic and lead to cancer. Since 2012, all girls in Sweden are offered vaccination against HPV to prevent cervical cancer, the most common HPV-related form of cancer. The vaccination is provided by school nurses in grade 5 or 6. HPV vaccination compliance is lower than other vaccinations in the National Vaccine Program for children in Sweden. School nurses play an important role in encouraging guardians to vaccinate their children, especially those who hesitate, to increase the number of girls getting vaccinated. Increasing compliance via school nurses´ actions can reduce the number of HPV related cancers in the long term. The aim of the study was to describe how school nurses in Halland, a province on the southwest coast of Sweden, react to guardians´ rejection of the HPV vaccination for girls in grade 5 or 6. Also queried was what these nurses hear as the reasons for refusal. The assessment method selected was a web-based survey. The survey link was provided to 101 school nurses at schools teaching 5th and 6th grade in the six municipalities of Halland. The response rate was 56 percent and the results show that the school nurses in Halland do not react at all when guardians decline vaccination. The reasons given are that they believe that vaccinations are voluntary and/or that vaccinations are offered again in later grades. School nurses perceive that disinformation on the internet, fear of side effects and the young age of the girls are the main reasons for guardians´ declining HPV vaccination. Conclusion: Further motivation among school nurses in Halland is needed to increase HPV vaccination compliance.

Human papillomavirus (HPV) is widespread in the population and an important concern for public health. HPV-associated benign and cancerous disease is vaccine preventable yet vaccine uptake has been suboptimal. Adolescents are the primary target for vaccination yet their perspective has been inadequately examined. Ontario provides population-based preventive HPV vaccination to adolescent girls yet in the program’s first 2 years only approximately half of eligible girls received it. Effective strategies to improve vaccine uptake are needed. This thesis proposes a theory and ethics-based model to guide health promotion planning for HPV vaccination. Adopting an adolescent perspective, the model is applied and comprises: 1) a systematic review to identify barriers and facilitators to HPV vaccination from the viewpoint of young females; 2) GIS uses for communicating geospatial health information regarding vaccination; and 3) a roadmap for the future including recommendations for guiding principles, research, intervention development, and health policy.

<p><b>In this dissertation we present the quantitative response of an epidemic of the so-called SIR-type, in a population consisting of a local component and a migrant component. Each component can be divided into three classes, the susceptible individuals, usually denoted by S, who are uninfected but may contract the disease, infected individuals (I) who are infected and can spread the disease to the susceptible individuals and the class (R) of recovered individuals. If a susceptible individual becomes infected, it moves into the infected class. An infected individual, at recovery, moves to the class R. Firstly we develop a model describing two interacting populations with vaccination. Assuming the vaccination rate in both groups or components are constant, we calculate a threshold parameter and we call it a vaccination reproductive number. This invariant determines whether the disease will die out or becomes endemic on the (in particular, local) population. Then we present the stability analysis of equilibrium points and the effect of vaccination. Our primary finding is that the behaviour of the disease free equilibrium depend on the vaccination rates of the combined population. We show that the disease free equilibrium is locally asymptotically stable if the vaccination reproductive number is less than one. Also our stability analysis show that the global stability of the disease free equilibrium depends on the basic reproduction number, not the vaccination reproductive number. If the vaccination reproductive number is greater than one, then the disease free equilibrium is unstable and there exists three endemic equilibrium points in our model. Two of these three endemic equilibria are so-called boundary equilibrium points, which means that the infection is only in one group of the population. The third one which we focus on is the general endemic point for the whole system. We derive a threshold condition that determines whether the endemic equilibria is locally asymptotically stable or not. Secondly, by assuming that the rate of vaccination in the migrant population is constant, we apply optimal control theory to find an optimal vaccination strategy in the local population. Our numerical simulation shows the effectiveness of the control strategy. This model is suitable for modeling the real life situation to control many communicable diseases. Models similar to the model used in the main contribution of our dissertation do exist in the literature. In fact, our model can be regarded as being in-between those of [Jia et al., Theoretical Population Biology 73 (2008) 437-448] and [Piccolo and Billings, Mathematical and Computer Modeling 42 (2005) 291-299]. Nevertheless our stability analysis is original, and furthermore we perform an optimal control study whereas the two cited papers do not. The essence of chapter 5 and 6 of this dissertation is being prepared for publication.</b></p>

Reproduction de : Thèse d'exercice : Médecine : Nancy 1 : 2006. / Titre provenant de l'écran-titre.

As Africa faces the challenges of its renewal or renaissance, the HIV/AIDS epidemic poses the greatest potential barrier to the attainment of this vision (Makgoba, 2001 in Dorrington, Bourne, Bradshaw, Laubscher & Timaeus, 2001). The development of an HIV vaccine that is safe, effective and affordable, has been widely contemplated as a necessary supplement to already established interventions. In preparation for HIV vaccine trials in South Africa the current project aimed to assess students' understanding (knowledge and perceptions) and experiences of vaccination in general, and to explore if these were associated with demographics such as motherhood and gender. A parallel aim was to assess students' knowledge and expectations of HIV vaccination and trial participation. A sample of 33 students was recruited from university residences at the University of Natal, Pietermaritzburg. Participants were interviewed via a semi-structured interview schedule. The data collected was then coded and analysed using content analysis, while Chi - square analysis was used to evaluate if demographics such as gender and motherhood were systematically associated with various responses. The results revealed that the vast majority of participants (97%) knew the purpose of vaccination, stating that it was to promote health and prevent illness. Most participants (67%) knew that vaccination works by mobilising the immune system (vaccination mechanism). The vast majority of participants (91%) could name at least one vaccine preventable disease. Uptake of childhood immunisation was reportedly high (88%) while adult uptake of immunisation was low (33%). A significant minority (36%) reported that they had experienced side effects but understood these to be an integral part of vaccination. Thirty percent of participants stated they were willing to participate (WTP) in a hypothetical vaccine trial, 33 % of participants were not WTP and 15% were not sure. Motivations for trial participation were reportedly influenced most by personal incentives of altruism (39%) and barriers such as perceived significant physical risk (61%). In general, knowledge and experiences of vaccination were not associated with gender or with motherhood. The results suggest that more awareness of HIV vaccine trials is needed. In this regard education should emphasise that the prospective vaccine will be preventive, that only healthy people can volunteer and that the HIV vaccine will not guarantee immunity to HIV infection. Suggestions are made for future research into motivations, barriers and incentives to facilitate an ethical process of vaccine trial participation. / Thesis (M.Soc.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

<p><b>In this dissertation we present the quantitative response of an epidemic of the so-called SIR-type, in a population consisting of a local component and a migrant component. Each component can be divided into three classes, the susceptible individuals, usually denoted by S, who are uninfected but may contract the disease, infected individuals (I) who are infected and can spread the disease to the susceptible individuals and the class (R) of recovered individuals. If a susceptible individual becomes infected, it moves into the infected class. An infected individual, at recovery, moves to the class R. Firstly we develop a model describing two interacting populations with vaccination. Assuming the vaccination rate in both groups or components are constant, we calculate a threshold parameter and we call it a vaccination reproductive number. This invariant determines whether the disease will die out or becomes endemic on the (in particular, local) population. Then we present the stability analysis of equilibrium points and the effect of vaccination. Our primary finding is that the behaviour of the disease free equilibrium depend on the vaccination rates of the combined population. We show that the disease free equilibrium is locally asymptotically stable if the vaccination reproductive number is less than one. Also our stability analysis show that the global stability of the disease free equilibrium depends on the basic reproduction number, not the vaccination reproductive number. If the vaccination reproductive number is greater than one, then the disease free equilibrium is unstable and there exists three endemic equilibrium points in our model. Two of these three endemic equilibria are so-called boundary equilibrium points, which means that the infection is only in one group of the population. The third one which we focus on is the general endemic point for the whole system. We derive a threshold condition that determines whether the endemic equilibria is locally asymptotically stable or not. Secondly, by assuming that the rate of vaccination in the migrant population is constant, we apply optimal control theory to find an optimal vaccination strategy in the local population. Our numerical simulation shows the effectiveness of the control strategy. This model is suitable for modeling the real life situation to control many communicable diseases. Models similar to the model used in the main contribution of our dissertation do exist in the literature. In fact, our model can be regarded as being in-between those of [Jia et al., Theoretical Population Biology 73 (2008) 437-448] and [Piccolo and Billings, Mathematical and Computer Modeling 42 (2005) 291-299]. Nevertheless our stability analysis is original, and furthermore we perform an optimal control study whereas the two cited papers do not. The essence of chapter 5 and 6 of this dissertation is being prepared for publication.</b></p>

Introduction En juin 2009, l’Organisation Mondiale de la Santé (OMS) a déclaré l’état de pandémie pour le nouveau virus influenza A(H1N1). Malgré les recommandations des autorités de santé publique, lors de la mise en place de la campagne de vaccination de masse au Québec contre ce virus pandémique, certains groupes de la population ont été plus enclins à être vaccinés que d’autres groupes. Ceci souligne l’importance des déterminants psychosociaux du comportement humain, sujet qui a donné cadre à notre étude. Objectifs Le but de cette étude a été de documenter les attitudes, les connaissances et les influences sociales des parents dont les enfants fréquentent des services de garde éducatifs (SGE) vis-à-vis la vaccination contre la pandémie ainsi que la couverture vaccinale. Méthodologie Un questionnaire auto-administré et anonyme basé sur la théorie des comportements interpersonnels de Triandis a été distribué aux parents d’enfants âgés de 0-59 mois de neuf centres de la petite enfance sur l’île de Montréal. Résultats Le taux de réponse de l’enquête a été de 32,0% (N=185). Le taux de vaccination des enfants s’est retrouvé à 83,4%; ceci représente une couverture plus élevée que la moyenne régionale et nationale. Toutefois, à une question sur l’intention des parents face à une autre pandémie, seuls 46% des parents feraient vacciner leur enfant. Les facteurs les plus significatifs associés à la vaccination de leur enfant ont été les croyances personnelles positives, de bonnes habitudes vaccinales et l’influence des média, tous mesurés par plusieurs indicateurs (RC respectifs de 7,7, 3,1 et 4,2, p<0,05). Conclusion Pour la grippe A(H1N1), plusieurs facteurs contextuels ont joué en faveur des taux de vaccination acceptables chez les enfants. Toutefois, la mise en place d’une campagne de la vaccination par les instances gouvernementales et de santé publique en utilisant divers média pourraient contribuer à un taux de vaccination encore plus élevé en cas d’épidémie ou de pandémie. / Background In June 2009, the World Health Organization (WHO) declared the 2009 A(H1N1) swine flu a pandemic. Despite the recommandations from public health authorities when setting up the mass immunization campaign in Quebec against the influenza A(H1N1), some population groups were more likely to be vaccinated than others. This underlines the importance of psychosocial determinants of human behaviour, which gave a framework for our study. Objectives The aim of this study was to document the attitudes, knowledge and social influences of parents whose children attend early childhood centers (ECC) regarding the vaccination against the pandemic and its coverage. Methods A self-administered and anonymous questionnaire based on the theory of reasoned action of Triandis was distributed to parents of children aged 0-59 months in nine childcare centers on the island of Montreal. Results The response rate of the survey was 32.0% (N=185). The vaccination uptake for children was 84%; this represents a higher coverage than the average regional and national levels. However, only 46% of the parents said that they would vaccinate their child again if a new flu pandemic was being declared by the World Health Organization. The most significant factors associated with vaccination uptake were positive personal beliefs, getting seasonal flu vaccines and the influence of media, all measured by several indicators (respective odds ratio 7,7, 3,1 and 4,2, p<0,05). Conclusion Several contextual factors played in favour of acceptable vaccination rates among children. However, the establishment of a campaign of vaccination by government authorities and public health agencies while using various media to spread information could contribute to higher vaccination rates in a future case of epidemic or pandemic.

This study was conducted to compare animal performance, presence of skin reactions and immune response following vaccination of beef calves via needle-free (NF) and needle-syringe (NS) vaccination techniques. Spring-born (Study A) and fall-born (Study B) calves were vaccinated against bovine viral diarrhea virus (BVDV) and Clostridium chauvoei (C. chauvoei) via NF and NS vaccination techniques. The parameters measured in this study included body weight (BW), skin reactions and serum antibodies. Animal performance and antibody levels against BVDV and C. chauvoei did not differ between vaccination techniques. However, NF vaccinated calves had a greater frequency of skin reactions when compared to NS vaccinated calves, except for day 42 of Study B. It can be concluded that a needle-free injection device (NFID) can be used effectively to stimulate an immune response without impacting animal performance, but may cause a greater frequency of skin reactions.

La vaccination ADN à l’aide de plasmides codant pour des autoantigènes s’est avérée efficace dans la protection contre plusieurs maladies auto-immunes. Le but de ce mémoire était dans un premier temps d’établir si un protocole de vaccination ADN composé de 3 injections de pCMV-CTLA-4-NP et de pVR-IL-12 à deux semaines d’intervalle avait un effet protecteur contre le développement d’une hépatite auto-immune chez la souris TTR-NP, un modèle murin transgénique de la maladie et précédemment développé au laboratoire. Dans un deuxième temps, le but était d’élucider, le cas échéant, les mécanismes sous-tendant la protection conférée par la vaccination ADN. Les hypothèses initiales étaient qu’une protection allait effectivement être conférée par la vaccination ADN et que celle-ci pouvait être attribuable à une déviation de la réponse typiquement Th1 de la maladie vers une réponse Th2, à un épuisement des cellules immunitaires et/ou à l’activation et à l’induction de prolifération de cellules régulatrices. Les résultats montrent que la vaccination ADN induit une protection transitoire contre le développement d’infiltrations lymphocytaires au foie. Cette protection se ferait via un épuisement des cellules CD4+, CD8+ et CD19+ se retrouvant à la rate et exprimant PD 1 dans une plus forte proportion à 3 mois, et ne serait médiée ni par les lymphocytes T régulateurs CD4+CD25+FoxP3+, ni par les cellules CD8+FoxP3+. Une déviation de la réponse Th1 vers une réponse Th2 demeure une explication supplémentaire plausible à la protection conférée mais nécessiterait une caractérisation en situation plus physiologique avant de pouvoir inférer sur son implication réelle. La vaccination ADN n’influe ni sur la présence d’autoanticorps, ni sur les niveaux d’alanine aminotransférase, deux marqueurs de la maladie. / DNA immunizations were proven effective in a range of autoimmune diseases. The first goal of this master’s thesis was thus to evaluate if a protocol of 3 intramuscular plasmidic injections of pCMV-CTLA4-NP and pVR-IL-12, at 2 weeks apart, would protect TTR-NP mice, a transgenic murine model previously developed in the laboratory, against the development of an autoimmune hepatitis. The second goal was, if the protection was indeed conferred by DNA vaccination, to elucidate the mechanisms underlying this effect. The initial hypotheses were that DNA vaccination would indeed elicit a protection against autoimmune hepatitis, and that this could be attributed to a skew from the typical Th1 response to a more tolerogenic Th2 response, to the exhaustion of the immune cells and/or to the activation and the proliferation of regulatory T cells. Results show that DNA vaccination induces a transient protection against lymphocytic infiltrates in the liver. This protection is thought to be caused by the exhaustion of the CD4+, CD8+ and CD19+ cells found in the spleen and expressing PD-1 in greater proportion at 3 months, and not to be mediated by CD4+CD25+FoxP3+ or CD8+FoxP3+ regulatory T cells. An immunomodulation from a Th1 to a Th2 response could still be a plausible explanation by the protection conferred by the DNA vaccination, but additional experimentations in a more physiological setting would be necessary to infer on its real implication. DNA vaccination had no effect on autoantibodies or on alanine aminotransferase levels, which are two biological markers of the disease.

This study was conducted to compare animal performance, presence of skin reactions and immune response following vaccination of beef calves via needle-free (NF) and needle-syringe (NS) vaccination techniques. Spring-born (Study A) and fall-born (Study B) calves were vaccinated against bovine viral diarrhea virus (BVDV) and Clostridium chauvoei (C. chauvoei) via NF and NS vaccination techniques. The parameters measured in this study included body weight (BW), skin reactions and serum antibodies. Animal performance and antibody levels against BVDV and C. chauvoei did not differ between vaccination techniques. However, NF vaccinated calves had a greater frequency of skin reactions when compared to NS vaccinated calves, except for day 42 of Study B. It can be concluded that a needle-free injection device (NFID) can be used effectively to stimulate an immune response without impacting animal performance, but may cause a greater frequency of skin reactions.