Burkholderia pseudomallei (Bp) is the causative agent of melioidosis, a disease with a mortality rate of over 40%, and is a major public health concern in the endemic regions of Thailand and northern Australia. Bp is a resilient pathogen capable of surviving in diverse environments including soil, fresh and seawater, and plant and animal tissues for extended lengths of time. Bp is intrinsically resistant to antibiotics, which contributes to persistence and relapse in over 25% of melioidosis patients, and there is currently no vaccine. Our lab has previously shown that immunization with Bp outer membrane vesicles (OMVs) derived from Bp grown in Luria Burtani broth provides significant protection against melioidosis in mice. However, this protection was limited to the acute phase of infection and animals immunized with OMVs were unable to clear the bacteria. In this work, we show that by manipulating the growth media to simulate various bacterial niches, including the natural hypertonic soil environment (NaCl-supplemented), the limited-nutrient host macrophage intracellular environment (M9CG minimal media), and quorum sensing conditions (QS-molecule supplemented), OMV protein content can be modified to include those proteins potentially important for Bp survival and may contribute to protection against chronic or persistent infection. Here, we characterize the composition of selectively enriched Bp OMVs and demonstrate that enriched OMVs are non-toxic and well-tolerated both in vitro and in vivo. Immunization of BALB/c mice with QS OMVs elicits significantly greater OMV-, CPS-, and LPS- serum IgG along with cell-mediated immune responses compared to mice immunized with LB OMVs. LB, M9CG, and QS OMV immunization provided equal protection against aerosolized Bp through the acute phase of infection, and M9CG OMV-immunized mice demonstrated fewer signs of morbidity and less weight-loss over the course of infection, indicating potential control of the bacteria. These results suggest that immunizing with OMVs selectively enriched with intracellular proteins may elicit the necessary immune responses to protect against persistent melioidosis. / Nicole L Kikendall

Pertussis (whooping cough) remains an important public health problem in Australia. Although mortality and morbidity from pertussis declined dramatically following the introduction of mass vaccination programs in 1953, the level of morbidity remains unacceptably high for a vaccine-preventable disease. Aims and methods The primary aims of this thesis were (i) to ascertain the epidemiology of pertussis in Australia between 1993 and 2000 by analysing and interpreting sources of routinely collected data on pertussis; and (ii) to examine the effectiveness of vaccination against pertussis in a number of ways. Data from three primary national sources (notifications of disease, hospitalisations for pertussis and death certificates) were used to examine the burden from pertussis in Australia over these eight years. Analyses included the age distribution of cases, temporal and geographic trends, comparisons of notification and hospitalisation data, and the impact of differences in the method of diagnosis of notified cases between years and age groups. In addition to analyses at the national level using data from the national databases, further detailed analyses were undertaken at the State level for New South Wales (NSW), the most populous Australian State. Pertussis vaccine coverage was estimated using data from the recently established Australian Childhood Immunisation Register (ACIR); these data were also used to track the transition from whole-cell to acellular pertussis vaccines. The different types of studies used to evaluate vaccine effectiveness were reviewed, and a method suitable for ongoing estimation of vaccine effectiveness in Australia was developed. This was then applied to the NSW data, to determine the effectiveness of pertussis vaccination in this State. Main findings The annual notification rate for pertussis in Australia ranged from 23�59 per 100 000 population over the eight years. Infants had the highest notification and hospitalisation rates in Australia � they accounted for 5percent of notifications, 61percent of hospitalisations and 100percent of deaths. Age-specific notification and hospitalisation rates in children aged less than two years strongly suggested a protective effect of vaccination, with the greatest reduction in rate coinciding with eligibility to receive a second dose of pertussis vaccine at four months of age. Notification rates among 5�9 year olds progressively decreased in successive age cohorts, consistent with an effect of the introduction in 1994 of a pertussis vaccine booster for preschool-aged children. Although adults (persons aged 15 years or more) accounted for half the notifications, they had the lowest notification rate. The highest numbers of pertussis notifications were in 1997, when most jurisdictions experienced an epidemic. Notification and hospitalisation rates varied across the States and Territories and also across smaller geographic regions in NSW. Areas and years with high notification rates tended to also have high hospitalisation rates, suggesting that trends in notifications reflected trends in incidence. The number of infant hospitalisations in NSW between July 1993 and June 1999 exceeded the number of notifications by 32percent, highlighting the extent of under-notification. Overall, and particularly amongst those aged more than 12 months, the majority of cases notified in NSW were based on the results of serological tests. The proportion diagnosed by culture of the organism was greatest in infants; the proportion diagnosed by serological tests increased with age. There was no evidence that the use of serology had increased since 1994 in NSW, hence changes in notification rates after this time are unlikely to be attributable to increased use of serological diagnosis. ACIR records indicated that in December 2000, 92percent of one-year-old children had received three doses of diphtheria-tetanus-pertussis (DTP) vaccine and 90percent of two-year-olds had received four doses. Vaccine coverage varied by jurisdiction. Since 1997, there was an increased use of DTP vaccines containing acellular pertussis components with a corresponding decrease in the use of vaccines containing whole-cell components. In 2000, almost all DTP vaccines administered contained acellular pertussis components. The results of the vaccine effectiveness study showed that pertussis vaccination was highly effective at preventing pertussis in NSW children, as measured by notified cases. Vaccine effectiveness was highest (91percent) in the youngest age group (8�23 months) and lowest (78percent) in the oldest age group (9�13 years). The screening method has not previously been used to estimate pertussis vaccine effectiveness in Australia. Conclusions This thesis demonstrates the value of integrating varied data sources in estimating the disease burden from pertussis. The data presented here show that the disease burden is substantial in all age groups, despite high levels of vaccine coverage in infants and children. This problem of disease control does not appear to be due to lack of vaccine effectiveness, but there is evidence of waning immunity over time. The analyses presented here form a basis for the ongoing monitoring of trends in pertussis epidemiology following the replacement of whole-cell by acellular pertussis vaccines, and will assist consideration of the need for additional booster doses in adolescents and adults.

Babesiosis is caused by a genus of tick-transmitted apicomplexan parasites with considerable economic, medical, and veterinary impact. Bovine babesiosis is an important impediment to livestock production throughout the world. Limited options are available for control of this widespread protozoal disease. This study evaluated the protective effect of DNA vaccines incorporating Babesia cysteine proteases and Apical Membrane Antigen-1 separately and in combination. The Helios Gene Gun System was used to vaccinate BALB/c mice with plasmid DNA constructs encoding different B. microti proteins (pBmCP1, pBmAMA1 or a combination of pBmCP1 and pBmAMA1). An analysis of the parasitemia post-challenge supports the hypothesis that pBmCP1 and pBmAMA1 induce protective effects against the progression of the parasite. However, the combination of the two constructs given simultaneously has no marked effect on parasite progression. Furthermore, the data obtained from the packed cell volumes of the mice indicates that only BmCP1 is able to reduce this effect of clinical disease with any level of significance. Babesia bovis constructs containing Cysteine Protease-2 and Apical Membrane Antigen-1 were created and sequence verified for use in future vaccination studies. The results seen using the mouse model of Babesiosis may provide applicable information for the design of vaccines against other Babesia spp., particularly for B. bovis.

Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.

Thesis (MSc (Production Animal Studies, Veterinary Science)--University of Pretoria, 2009. / Includes bibliographical references. Also available in print format.

Pneumonia is one of the top causes of deaths in children younger than 5 years of age. According to WHO estimation, globally there are nearly 2 millions young children who die from pneumonia every year, and more than 70% of these deaths occurred in Africa and Southeast Asia. Pneumonia caused by Streptococcus pneumoniae (also called pneumococcus) is a vaccine preventable disease, accounting for 39% of community-acquired pneumonia. There are two types of pneumococcal vaccines that are pneumococcal polysaccharide vaccine (PPV) and pneumococcal conjugate vaccines (PCV). The latter one is routinely advised for children younger than five years. The aims of this paper are to review the global disease burden caused by Streptococcus pneumoniae in children younger than 5 years and to gather vaccine program information globally. For narrative review and policy analysis, WHO websites, other websites of health organizations or institutions, and literatures from Pubmed were reviewed, using key words “children pneumonia”, “Streptococcus pneumoniae”, “pneumonia vaccine”, “pneumococcal conjugate vaccine ”, “PCV-7”, “7-valent PCV”, “PCV-13”, “13-valent PCV”. Numerous literatures have reported that obvious incidence decrease of invasive pneumococcal diseases (IPD) in young children after PCV vaccination. In July 2000 PCV-7 (“7-valent pneumococcal conjugate vaccine”) was incorporated into National Immunization Program (NIP) in United States. Although since then the incidence of IPD caused by vaccine-covered serotypes markedly decreased, those caused by non-vaccine-covered serotypes were found substantially increased. In February 2010, PCV-13 (“13-valent pneumococcal conjugate vaccine”) replaced PCV-7 in NIP in United States. With a wider range of serotypes, PCV-13 was expected to be more effective than PCV-7 in children under 5. Using modeling method, many scholars estimated that PCV-13 was likely to be more cost-effective in reported settings when herd immunity was taken into consideration. Schedule of vaccine was another issue that needs to be investigated. There are three schedules commonly adopted by health authorities: 2 primary doses with 1 booster dose (2p+1), and 3 primary doses with 1 booster (3p+1) or without 1 booster dose (3p+0). In individual report, it seems three schedules were all effective. From result of systematic review, more evidence supported to use 3p+0 schedule (and 3p+1 schedule). However, emerging evidences are in support of 2p+1 schedule tool. WHO recommended both 3p+0 and 2p+1 schedule. If the country with high incidence rate in young infant (less than 32 weeks) 2p+1 schedule may not provide adequate protection for special individual serotype. In addition 2p+1 schedule may also lead to lower antibody level between the second primary dose and the booster dose, but the booster dose could induce higher antibody level, which is important for protecting certain serotypes. Countries should consider local factors and choose suitable vaccine schedule accordingly. In terms of global PCV programs, around 80 countries have already added PCV into their NIP, 58 countries (30%) were planning to introduce the program; nevertheless remaining 51 countries (26%) of countries have no schedule to introduce it yet. Most countries that have implemented PCV programs were western industrialized countries. With support from Global Alliance for Vaccines and Immunization (GAVI), 15 eligible African countries have had routine PCV programs. Comparatively, in Asia, India and China, two countries with the largest population and largest number of IPD cases in the world, have no PCV program to the children. Even industrialized economies like Japan and Taiwan have not implemented yet. Asia was lagging behind for decades. PCV program needs to be prioritized in Asian countries. Asian governments should consider investing more in PCV programs (high-income countries) and/or cooperating with other organizations such as GAVI (low-income countries) to increase the coverage of PCVs in children under 5 and to protect them from pneumococcal diseases. / published_or_final_version / Public Health / Master / Master of Public Health

Objectives: By summarizing and comparing the pattern of invasive pneumococcal disease (IPD) in the 4 areas (namely Hong Kong, other parts of China, United States and Thailand) at different stages of implementation of universal pneumococcal vaccination, a snapshot picture could be obtained to visualize how pneumococcal vaccination has impacted upon various important measures, including the burden of IPD, prevalent serotypes, antimicrobial resistance, risk factors of IPD, to guide us on the next step to optimize our ability to combat against IPD. Methods: To achieve the objective, a systematic search through PubMed, Medline, Cochrane Library, EmBase, CINAHL, and the China Journal Net (for Chinese journal articles to obtain a more comprehensive data for “other parts of mainland) has been performed. Articles were selected according to the inclusion and exclusion criteria, and in straight accordance to the literature search and article retrieval steps as described in the methodology. The quality of the articles was assessed by the STROBE (Strengthening the Reporting of Observational studies in Epidemiology) checklists. Results: In general, there was decline in IPD incidence after PCV vaccination, but the problem of serotype replacement and antimicrobial resistance was still an ongoing problem, which differs geographically. Conclusion: From the above data, we could see the significant impact on PCV on reduction of incidence in IPD as shown in United States, however, it was also very clear that unless development of non-serotype specific vaccine become available to us, we are still facing the problem of serotype replacement and that we need to have regular surveillance, as in the case of United States, to supply the data for timely replacement of new PCV combating the emerging serotypes, such that we would still be in the safe ground. In Hong Kong, the statutory reporting of IPD to Centre for Health and Protection (CHP) has been effective since 2/1/201443, after the start of universal immunization since October 2008, followed by PCV10 in 2009 and PCV13 in December 2011, we seems lacking behind on the surveillance. With the surveillance started by CHP, we hope to understand the Hong Kong situation better and with more published data for our local burden and serotype pattern of IPD. It is interesting to note that the antimicrobial pattern does vary geographically, even in US with universal immunization. This suggests that while PCV was helping us to reduce the penicillin resistant strain, another more important factor – the practice of use of antibiotics- is still operating to effect on the overall antibiotic resistance. The pattern that rural Thailand was having much much less penicillin resistance as compared to urban Bangkok, where antibiotic is more readily available, also supports this explanation. / published_or_final_version / Public Health / Master / Master of Public Health

Influenza (IV) and pneumococcal polysaccharide vaccination (PPV) may reduce hospitalization and mortality but the effectiveness of these vaccines in older adults (≥65 years) is controversial. This thesis includes seven parts with a total of ten studies studying different aspects regarding IV and PPV in institutionalized older adults - the group with the highest infection-related morbidity and mortality. 　　 　　In Part I, we presented the controversies about effectiveness of influenza and pneumococcal vaccination in institutionalized older adults. 　　 　　In Part II, we studied a retrospective cohort of 1737 older adults showing that nursing home residence is independent risk factor of infection-related mortality and hospitalization. 　　 　　In Part III, the second and third studies were systematic reviews showing that IV and PPV could reduce pneumonia and death.. 　　 　　In Part IV, we evaluated the effectivenss of IV and PPV through prospective cohorts. The fourth study was a prospective cohort study of 1859 institutionalized older adults showing that IV significantly reduced mortality and hospitalization. The fifth study was a prospective cohort study of 532 institutionalized older adults showing that when the IV strain does not match the circulating strain, PPV provided additional protection in reducing mortality. 　　 　　In Part V, the sixth study was a randomized controlled trial of 100 institutionalized older adults showing that intradermal IV has better immunogenicity than intramuscular vaccination without compromising safety. 　　 　　In Part VI, we identified factors that may affect clinical effectiveness of IV. The seventh and eighth studies were prospective cohort studies of 711 institutionalized older adults showing that vaccine efficacy declined with increasing impaired functional status and renal function. 　　 　　In Part VII, we identified determinants of receiving IV and PPV in institutionalized older adults. The ninth study was a cross-sectional study of 155 institutionalized older adults showing that encouragement from nHCWs was a major facilitator of receiving vaccination. The tenth study was a cross-sectional study of 1300 nHCWs showing that 40.2% of nHCWs had encouraged residents to receive vaccination. 　　 　　In conclusion, ten studies from this thesis demonstrated that IV and PPV are effective in preventing hospitalization and reducing mortality in institutionalized older adults. Different strategies in improving its effectivenss and acceptance were suggested. / published_or_final_version / Medicine / Master / Doctor of Medicine

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Introduction: Thousands of people die from influenza or its complications each year despite the fact that it is one of the few vaccine preventable diseases. Immunocompromised cancer patients are among the most vulnerable to this infection and flu‐related complications, and therefore vaccination is highly recommended in these patients; however, current vaccination rates and attitudes towards vaccination remain unknown. We hypothesize that immunization rates are lower than the 100% recommendation rate, and hope to understand the reasoning behind the discrepancy. The purpose of this study is to assess cancer patient attitudes towards influenza vaccination in an effort to minimize barriers to vaccination and eventually increase vaccination rates in this immunocompromised population. Methods: Cancer patients enrolled in phase I clinical oncology trials at the Virginia G Piper Cancer Center at Scottsdale Healthcare were invited to participate in a voluntary survey. The 15‐item survey consisted of demographic information, knowledge regarding the flu vaccine, vaccination status after cancer diagnosis and while on treatment, and general attitudes towards vaccination. A total of 84 cancer patients completed the survey. Results were stratified by age, gender, education level, and vaccination status. As this was a descriptive study, no statistical analyses were performed. Results: A total of 84 (n=84) advanced cancer patients enrolled in phase I clinical oncology trials completed the survey. Results indicate that although 71% of patients received the vaccine prior to cancer diagnosis, only 58% of patients have received the vaccine since their cancer diagnosis, and only 48% have been vaccinated while on cancer treatment. Of those vaccinated since cancer diagnosis, 94% reported doctor recommendation of the vaccine and most vaccinate to protect themselves from the virus. Of those not vaccinated since cancer diagnosis, only 37% report their doctor recommends the vaccine and the majority avoid vaccination because they believe the vaccine can cause the flu, they do not feel at risk of infection, and they do not believe the vaccine is effective. Conclusion: Our findings suggest that although the CDC strongly recommends influenza vaccination in cancer patients due to the risk of secondary complications and even death in these immunocompromised individuals, vaccination rates remain low. Our data demonstrates that patients who receive a doctor recommendation for the vaccine are more likely to be vaccinated, but not all doctors recommend the vaccine. Furthermore, false information regarding the vaccine, its efficacy, and its ability to cause infection continues to deter patients from vaccination. Together, this information offers profound insight into the cancer patient population and suggests the need for increased physician and patient education regarding the benefits of annual influenza vaccination to improve vaccination rates and decrease influenza infection and complications in the future.

First in 1997, and later re-emerging in 2003, highly pathogenic avian influenza A virus, subtype H5N1, has spread from wild bird reservoirs to domestic bird flocks. As a result, cross-transmission has been confirmed in people living or working in close contact with infected birds. H5N1 virus infection is associated with a high mortality rate (>60%) in humans and the rapid evolution of the virus suggests that it could potentially develop into a new, and possibly severe, pandemic influenza virus. To-date, conventional inactivated and live-attenuated vaccine strategies offers the best protection against influenza virus infection; however, poor immunogenicity and weaker efficacy have been observed against H5N1 viruses. It was hypothesized that experimental adenovirus-based vaccines based on human adenovirus serotype 5 (AdHu5) or porcine adenovirus serotype 3 (PAV3) can offer protection against a broad range of avian influenza, subtype H5N1, viruses. Ad vaccine vectors are highly immunogenic and have demonstrated protective efficacy against several disease models. However, natural immunity against AdHu5 can interfere with vector efficacy. The nonhuman PAV3 was not neutralized by pooled human serum from 10,000-60,000 individuals and offers a promising alternative to AdHu5-based vectors. Systematic antigen screening using DNA vaccines identified the hemagglutinin (HA) glycoprotein as the most immunogenic H5N1 antigen. HA was then inserted directly into PAV3 or AdHu5. Comparable immune responses were observed between both vectors but, interestingly, the PAV3-based vaccine generated stronger T-cell responses and better rapid protection 8 days following immunization. Additionally, better long-term protection 1 year following vaccination was observed with the PAV3-HA vaccine. The co-administration of multiple H5N1 antigens was also screened to improve protection against divergent H5N1 challenge. Combinations of DNA vaccines expressing (HA+NA) and (HA+NP) offered the best promise for enhancing protection against homologous and heterologous H5N1 challenges, respectively. However, addition of three or more antigens reduced overall protection possibly by antigen dilution, competition, or interference. Co-administration of PAV3 or AdHu5 vectors expressing both the HA and NP antigens reduced protection against homologous and heterologous H5N1 virus challenges. For all combination vaccines, T-cell responses were strong against HA but significantly decreased against additional antigens in each combination vaccine. Overall, the experimental porcine-based Ad-based vaccine offered better protection than the H5N1 conventional vaccine against a broad range of different H5N1 viruses. Understanding of the relationship between immune parameters and protection will be critical in future improvement of adenovirus-based and other vaccines against avian influenza H5N1.