Browsing by Subject "vaccine"

Now showing 1 - 6 of 6
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    Enhancing control of porcine rotavirus through the identification of candidate B cell epitopes
    (2020-08) Shepherd, Frances
    From the moment piglets are born, their welfare is threatened by rotavirus (RV), a highly prevalent cause of acute diarrheal disease and mortality. Scientists and producers continue to grapple with how to improve vaccine and surveillance strategies to reduce infections. This ongoing challenge is due in part to a lack of information on which genetic changes within RV drive immune escape. The goals of this dissertation are twofold. We first aimed to investigate whether viral presence or detection in feces can be ameliorated by improved timing of prefarrow immunization. Our second aim was to elucidate B cell epitopes (BCEs) on the capsid proteins VP7 and VP4 to identify possible genetic drivers of vaccine immune escape and antigenic diversity. In Chapter 2, a longitudinal study on a commercial farm assessed whether the timing of prefarrow natural planned exposure (NPE) impacts the levels of RV detected in piglets’ feces. RV was continuously detected regardless of the number of NPE doses, and hypothesized that genetic changes at BCEs contribute to immune escape. We pursued this line of inquiry by elucidating BCEs with a bioinformatic approach. In Chapter 3, we validate and apply an in silico method to predict BCEs of RV VP7. In Chapter 4, we predict BCEs on the VP8*, the VP4 cleavage product that mediates host cell attachment. Alanine mutations at two predicted BCEs resulted in lower antisera binding titers, suggesting that the predicted sites were functional in antibody binding. This research provides evidence that computational approaches can yield immunologically-relevant information from RV sequence data alone and provides the first attempt at characterizing antigenic sites of RVB and RVC. Future surveillance efforts that focus on the predicted epitopes could help producers anticipate the accumulation of antigenic distance between vaccine and field strains, which will be crucial for improving vaccines and supporting piglet health.
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    MMR vaccination does not cause autism.
    (2010-09-15) Winkelman, Tyler
    There is no increased risk of autism or autism-spectrum disorder associated with the MMR vaccine. The MMR vaccine remains a safe and effective vaccine for children worldwide.
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    There is no significant difference in rates of autism in children receiving the MMR vaccine versus those who are not vaccinated
    (2008-11-24) Verdoorn, Jared
    A retrospective cohort study conducted in Denmark studying all the children born in the country between 1991 and 1998 revealed that there was no increased risk of autism in children receiving the MMR vaccine versus those who were not vaccinated. The relative risk of developing autism in those vaccinated for MMR versus the unvaccinated was 0.92, with a 95% confidence interval of 0.68 to 1.24, showing no significant difference.
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    Vaccines do not cause autism
    (2009-09-18) O’Brien, Sean
    Some parents have enough concern about a proposed link between vaccinations and autism that they delay or refuse to immunize their children. The evidence clearly shows that there is no link between vaccinations and autism.
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    Vaccines do not cause autism
    (2010-09-15) O’Brien, Sean
    Some parents have enough concern about a proposed link between vaccinations and autism that they delay or refuse to immunize their children. The evidence clearly shows that there is no link between vaccinations and autism.
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    What drives willingness to vaccinate and vaccination acceptance? Examining decision-making for seasonal influenza vaccine in Minnesota and a vaccine against an emerging pathogen in Uganda
    (2020-03) Bonner, Kimberly
    Introduction: The World Health Organization named vaccine hesitancy as a top-ten global health threat. To address hesitancy, there is a need to understand vaccination decision-making. Purpose: The purpose of these three studies was to assess: (1) what opinions are associated with annual influenza vaccination, (2) factors that motivate willingness to receive seasonal influenza vaccine by age in Minnesota and (3) factors that motivate willingness to receive a new vaccine against an emerging pathogen among university students in Uganda. 
Methods: We conducted two discrete choice experiment (DCE) surveys: one with 1,803 Minnesota adults on influenza vaccine and one with 1,600 students in Kampala, Uganda on a new vaccine against an emerging pathogen. We conducted two studies with the Minnesota survey data. We assessed if four different opinions towards vaccines were associated with annual influenza vaccination and if this association differed by age group. We evaluated the association between vaccination messages, the sources of message, incentives, and access on willingness to take an influenza vaccine using a panel of DCE questions. We evaluated the DCE data using a multinomial mixed logistic regression with random effects parameters. Additionally, we used data from this survey to assess associations between opinions and annual influenza vaccination using logistic regression. In the Kampala DCE, we evaluated the association between disease risk, disease severity, trusted individuals, influential voices, vaccine protection, and vaccine side effects on willingness to take a new vaccinate against an emerging pathogen using mixed logistic regression with random intercepts. Results: In our influenza vaccine analysis, we found that those with positive opinions of vaccines had at least 2.3 times higher odds of annual vaccination than those with negative opinions. We found that older age groups were more likely than younger groups to receive the influenza vaccine annually, and the association between positive vaccination opinions and annual vaccination was modified by age group, with a stronger association between positive opinions and annual vaccination in older age groups compared to younger age groups. Participants preferred to receive an influenza vaccine without an appointment and with a $5 gift card, compared to the other options. For a vaccine against an emerging pathogen, we found that increasing risk of disease exposure and increasing fatality disease rate were key drivers of vaccination willingness, compared to the other options. We found that vaccination willingness differed between medical/public health students and those from other disciplines. 
Discussion: Results from these studies suggest that for influenza vaccine, vaccination access and incentives are key drivers of willingness to be vaccinated. For a new vaccine against an emerging pathogen, disease risk and severity are key drivers of willingness to be vaccinated. 
 Conclusion: Vaccination decision-making is context-dependent. To understand and increase vaccination willingness, there is a need to consider the disease, the vaccine, and the population.