Vaccination, one of public health’s greatest disease prevention tools, is broadening to focus on adolescents. Now that there are more vaccines targeted specifically for adolescents, it is time to give more focus to vaccine delivery in this population. This research will increase the knowledge base to support informed changes in adolescent vaccine delivery by identifying knowledge and attitudes of adolescents toward vaccination within the context of barriers and solutions. Perceived susceptibility to disease, benefits and barriers to vaccination and other constructs were collected through a survey to 1368 high school students. In this population, a scheduled adolescent healthcare visit is feasible, vaccine education can diminishes health misconceptions, and vaccination mandates are ways to reach some students.

Pagrindimas: Informuotumas ir požiūris į vakcinaciją, vakcinas yra svarbus, nes: • Svarbu, kad žmonės suprastų vakcinų naudą, tiek apsisaugant nuo pavojingų užkrečiamųjų ligų, jų komplikacijų, mirties, tiek ekonominę naudą, nes lėšos vakcinacijai daug mažesnės (10 – 17 kartų) nei lėšos susirgusiems gydyti. (5) • Lietuvos valstybė iš biudžeto (Nacionalinėje imunoprofilaktikos 2006 – 2008 metų programoje numatyta skirti 740000 litų suaugusiųjų skiepijimui nuo difterijos ir stabligės) bei kitos užsienio šalys skiria dideles lėšas vakcinacijai, todėl svarbu, kad žmonės skiepytųsi. (6) • Nuo informuotumo ir požiūrio į vakcinaciją, vakcinas priklauso žmonių skiepijimosi mastai. Lietuvoje nuo gripo kasmet skiepijasi tik apie 5 proc. gyventojų. Dėl tokio mažo pasiskiepijančių skaičiaus gripo pandemijos atveju galime tikėtis vakcinos iš užsienio valstybių tik 16,5 – 17 proc. žmonių. Tai lemia technologiniai dalykai, kad pandeminės vakcinos šalis gali tikėtis triskart daugiau nei kasmet pasiskiepijama nuo įprasto gripo ir dar 10 proc. (7) Svarbu sužinoti žmonių požiūrį, informuotumą apie vakcinaciją, kad, esant reikalui, būtų galima keisti požiūrį, didinti informuotumą, kad padidėtų skiepijimo apimtys. Tyrimo tikslas: Nustatyti Vilniaus poliklinikų pacientų informuotumą apie vakcinas, vakcinaciją ir požiūrį į jas. Tyrimo uždaviniai yra: 1. Nustatyti (suaugusiųjų) Vilniaus miesto poliklinikų pacientų informuotumą apie vakcinas, vakcinaciją. 2. Nustatyti (suaugusiųjų) Vilniaus miesto... [toliau žr. visą tekstą] / Reasoning: The privity and attitudes to vaccination and vaccines is significant for the number of reasons: • It is important that people would understand the benefits of vaccines, both preventive – protection from various dangerous infectious diseases and complications – and economical – the expenses for vaccination are 10 to 17 times lower than those needed for the curing of infected (5). • Lithuanian Government and other countries allocate big expenses for the vaccination (there are 740 000 Lt devoted to inoculation of adults against diphtheria and tetanus in the National immunoprophylaxis program year 2006 - 2008), so it is important that people would vaccinate as required (6). • The degree of vaccination throughout people depends on privity and attitudes. Only 5 percent of people are inoculated against influenza in Lithuania every year. Due to this low number we can expect to receive vaccines from foreign countries only for 16.5 to 17 percent of people in the event of pandemic influenza. This is because of technological reasons, which mean that the nation can expect to receive amount of pandemic vaccine just three times more than annual number of inoculated patients, plus 10 percent (7). It is important to find out the opinion and privity of people about vaccination, so that we could change their points of view in order to increase the percentage of inoculation. Aim of the work: To determine the privity and attitudes of patients of Vilnius clinics about the vaccines and... [to full text]

Many countries, including Nepal, have been affected with highly pathogenic avian influenza (HPAI) outbreaks. There have been human mortalities in some countries and large numbers of poultry either died or were culled due to HPAI. The overall objective of this thesis was to improve our understanding of the epidemiology and economics of avian influenza (AI), and particularly HPAI, in Nepal. We determined the seroprevalence of and risk factors for AI virus antibodies presence in ducks in Kathmandu, Nepal. The estimated true prevalence of AI viruses (AIV) antibodies was 27.2% [95% Confidence Interval (CI): 24.6- 29.5]. Age of the ducks was identified as the only risk factor for AIV seropositivity. Ducks older than one year were more likely to be seropositive compared to ducks less than six months of age [Odds Ratio= 2.17 (95% CI: 1.07- 4.39)]. This study provided baseline information about seroprevalence of AIVs in Kathmandu that will benefit further research to differentiate the subtypes of AIVs circulating in Kathmandu. We also evaluated alternatives to the current control program (CCP) for HPAI in Nepal. The considered alternatives were: (i) absence of control measures (ACM) and (ii) vaccinating 60% of the domestic poultry flock twice per year. Cost-benefit analysis approach was used to evaluate the economic feasibility of the programs. In terms of the benefit-cost ratio, our findings indicated that there is a return of 1.96 dollars for every dollar spent in the CCP compared to ACM. The net present value of the CCP versus ACM was US$ 989,918. The vaccination program yielded a return of 2.41 dollars for every dollar spent when compared to the CCP. The net present value of vaccination versus implementing the CCP was US$ 13,745,454. These results support a continued investment into the CCP rather than ceasing to implement government regulated control measures and suggest that vaccination may be an even better control alternative. In summary, our studies have highlighted the value of epidemiologic and economic analysis in research of AI. Our results are expected to lead to an improved understanding and awareness of AI in Nepal and to formulation of better control strategies.

Conventional pertussis vaccine prepared from killed whole cell B. pertussis organisms has been in widespread use since the early 1950's. Despite marked reductions in the incidence of pertussis, the use of the vaccine has caused concern because of questions of significant adverse reactions. Whooping cough is not notifiable in South Africa, and there is consequently a paucity of hard data on efficacy; in addition few cases are proven. Incidence, prevalence, severity and transmission of the disease hence remain a matter of conjecture. In order to provide background information and determine baseline data for undertaking further studies, available clinical and epidemiological data on whooping cough (pertussis) in South Africa was collated. It was intended to compare the pattern of disease seen in this country with that known in other parts of the world. Clinical and epidemiological findings from 1525 whooping cough admissions (diagnosed on the basis of clinical criteria) obtained from 6 major infectious disease hospitals around the country for the period 1980-1987/1988 are reported. The data from Durban were available in some detail. Incidence, morbidity and mortality of the disease in South Africa, as elsewhere, was higher in infancy. Infants and young children were predominantly affected, with 31.3% of cases under 12 months of age and 7.2% less than 2 months. Mortality was disproportionately higher in infancy; 53 .2% of deaths were in those younger than 12 months of age. There was a slight female preponderance, both in respect of prevalence and mortality. Patients were admitted with pertussis throughout the year, although there was a peak during the winter months (May to October). The typical whoop accompanied the cough in 55.6% of patients . A raised white cell count was recorded in 66% of patients. The most commonly detected The average duration of hospital stay was between 1 0-13 days. Of those with vaccination records, 26% were unvaccinated, 44% had 1 or 2 doses, and 27% had been fully vaccinated with a whole-cell pertussis vaccine combined with diphtheria and tetanus toxoids. The picture, incomplete though it is, reveals a pattern of pertussis similar to that described in other developing countries. The study reveals huge gaps in our knowledge of this subject in South Africa. More research needs to be done, particularly with respect to improved diagnosis, prevention and treatment; further pertussis should be made a notifiable disease in South Africa. The whole-cell pertussis vaccine currently used in South Africa has not been adequately evaluated for post-vaccination events and immunogenicity. The development of new purified component pertussis vaccines, which appear to be safer than conventional whole-cell preparations and of equal or almost equal efficacy (although optimal vaccine composition remains to be defined), requires that the concept of early vaccination with this vaccine compared with conventional whole-cell vaccine be examined in order to optimise the immune response to these vaccines in infants; more especially since neonates do not appear to benefit from passive immunity. Acellular pertussis vaccine has not been evaluated previously in neonates. In order to address the problem of high morbidity and mortality from pertussis in early infancy; and the incorporation of the vaccine into routine vaccination schedules, a phase 11 trial of acellular and whole-cell vaccines was undertaken in very young infants. The effect of neonatal vaccination with acellular pertussis vaccine on subsequent immunity; and the immunogenicity and shortterm safety and reactogenicity of routine primary vaccination with acellular vaccine compared with conventional whole-cell preparations was investigated. Three hundred and forty-five healthy, full-term African babies were, enrolled in the study at birth; 58% of whom were successfully followed for 9 months. Infants were assigned to 1 of 3 vaccine groups in sequence at birth and received either acellular or whole-cell pertussis vaccine , combined with 0 and T (A-OTP or W-OTP) at 2, 4 and 6 months of age. Groups I and 11 received A-OTP and Group III W-OTP. In addition, at birth, Group I received an additional dose of A-OTP and Group 11, a saline placebo injection. No unvaccinated controls were studied for ethical reasons. Serologic IgG responses to 3 major protective antigens of B. pertussis, filamentous haemagglutinin (FHA), pertussis toxin (PT) and fimbrial agglutinogens 2,3 (AGG2,3), were measured by ELlSA in sera obtained at birth, and before vaccination at 2, 4 and 6 months and at 9 months of age. The incidence and nature of post-vaccination events were recorded for 14 days after each dose. A-OTP induced serum IgG responses to PT and FHA comparable with those reported in other studies, with peak PT titres occurring at 6 months of age after 2 doses in babies vaccinated according to the routine schedule (Group 11). Surprisingly, response to W-OTP was found merely to restore levels of antibody to PT and FHA to those found in cord blood after 3 doses of vaccine, which questions the immunogenicity of the South African product. Four doses of AOTP (Group I) did not produce a better antibody response than the 3-dose schedule. Incidence of all post-vaccination events to both acellular and whole-cell vaccines was low (85.96/1000 doses, 136.36/1000 doses and 76.30/1000 doses in Groups I, 11 and III respectively). Minor symptoms were more common in recipients of A-OTP, although no significant differences in rates were demonstrated. Neurologic post-vaccination events (without sequelae) occurred more frequently hi recipients of W-OTP. No infant vaccinated with A-OTP from 2 months of age (Group 11) experienced a neurologic symptom. The risks of major post-vaccination events cannot however be fully quantified In a study of this small size and diseases. A-DTP vaccination commencing at birth produced final antibody titres to PT and FHA which were superior to those of South African whole-cell vaccine but were considerably lower than when the vaccine was incorporated into routine schedules commencing at 2 months of age. The study findings suggest that acellular pertussis vaccines, whether given from birth or from the age of 2 months, appeared safer and produced a better serologic response than the South African whole-cell product which may have impaired immunogenicity. During the course of the above study, 11 full-term infants with pertussis infection (10 subclinical) were retrospectively diagnosed on the basis of ser~logic evidence. Of the infants with subclinical disease, all 10 had a ~ 4-fold rise in at least 2 different pertussis IgG antibodies and nine had ~ 4-fold rise in all 3 IgG antibodies measured. Seven infants had raised IgA antibodies to PT and FHA and 4 infants had raised IgA antibodies to AGG2,3. Subclinical infection provoked antibody production to multiple antigens to differing degrees. The role of various factors which may have contributed to asymptomatic infection were analysed, viz - household contacts; type of antibody response (clinical vs. subclinical; vaccinated vs. subclinical); maternally acquired antibody levels; vaccination status (number of vaccine doses received); age and gender; and nutritional status. SpeCial features of the study which require emphasis are: pertussis remained subclinical in unvaccinated babies (most of the subjects were unvaccinated). Subclinical infection followed incomplete primary vaccination with either acellular or whole-cell vaccines commencing at 2 months of age. Subjects were 8 months of age or younger and only 1 had completed primary vaccination. Other infections of infancy were commonly detected; 4 infants had upper Likelihood of subclinical infection was related to significantly lower levels of maternallyacquired pertussis IgG-AGG2,3 antibodies but not associated with infants' nutritional status. Subclinical pertussis is described in very young African babies at an age when the disease is most severe, and therefore has implications for infant morbidity and mortality; it is also relevant to disease surveillance and vaccine-efficacy studies . Some perinatal factors influencing vaccination were also explored . In this context we looked at: i. The acquisition of maternal antibodies to B. pertussis in paired mother-infant sera from both well -nourished and SGA full-term and pre-term infants, and infants who subsequently developed pertussis infection, and effect of these maternally-acquired antibodies on subsequent antibody responses to acellular pertussis vaccine administered soon after birth, and to acellular and whole-cell vaccines administered from the age of 2 months. if. The acquisition of maternal antibodies to diphtheria and tetanus (OT) in paired motherinfant sera from full-term and pre-term infants, and the effect of these maternallyacquired antibodies on serologic responses to neonatal OT vaccination followed by whole-cell OTP vaccination at 2, 4 and 6 months. Maternal antibodies were measured since little is known about materno-fetal transfer of pertussis antibodies, especially in African countries where inhibition of placental transfer might occur for a variety of reasons. Furthermore, the effect of peri-natal malnutrition and prematurity on transplacental transfer of diphtheria, tetanus and pertussis antibodies has not been conclusively established in these areas. sera with levels in the latter frequently being higher, Indicating active transplacental transfer of antibodies. The significant pertussis antibody levels in maternal sera were unlikely to be due to the currently used South African whole-cell vaccine (given the poor antibody response to PT and FHA shown in this study). It is assumed that the presence of these antibodies are the end result of natural infection and therefore that pertussis is widespread in the African community. Maternal and cord IgG-PT and AGG2,3 titres were significantly lower (p <0.05) and maternal IgG-FHA marginally lower (p ... O.05) in SGA infants compared to cohorts, although placental transfer was equally efficient in both groups~ This study has demonstrated that the high titres of maternally derived circulating B. pertussis antibodies do not have an inhibitory effect on the subsequent serologic response to acellular vaccine administered in early infancy (2 months) or with the first dose given soon after birth. Protective levels of diphtheria and tetanus antibodies were detected in 100% and 76% of cord sera in pre-term infants and in 85% and 67% of cord sera in full-term infants. Although the number of infants studied was too small to make a definite comment, there did not appear to be 'tolerance' due to neonatal diphtheria-tetanus vaccination of pre-term infants, or to high levels of maternally-acquired antibody. During analysis of the data from the phase 11 study of acellular pertussis vacclnes, 25 infants with protein-energy-malnutritlon (PEM) were detected on the basis of anthropometric indices. Seventeen infants were smaIJ-for-gestatlonal-age (SGA). of whom 9 developed PEM by the age of 9 months. Eight other infants developed post-natal PEM before the completion of the primary vaccination course. and extent of immunological impairment, if any, on the serologic responses to acellular vaccine and to conventional whole-cell OTP in SGA infants, and in infants who developed PEM before the completion of the primary vaccination course. The following indices were evaluated in malnourished infants; (i) anthropometric indices of nutritional status, (ii) intercurrent illnesses including pertussis infection, (iii) post-vaccination events, (iv) serologic responses to vaccination. Results were compared with those obtained in well-nourished (WN) age- and vaccine-matched cohorts. Overall, peak titres and seroconversion data of all 3 antibodies were not significantly different in malnourished infants though final anti-AGG2,3 titres (at 9 months of age) in Group III were significantly lower (p = 0.035). Although peak and final PT and FHA antibody titres in many SGA and malnourished infants were lower than in WN infants and peak responses were attained at a later age, malnutrition did not significantly affect the response to A-OTP. Peak and final AGG2,3 antibody titres were similar in SGA, malnourished and WN infants. Overall malnourished infants responded no less well to pertussis vaccination than did other vaccinees. Incidence of minor local and systemic post-vaccination symptoms was not significantly different in PEM and WN groups although induration at injection site and irritability were more frequently reported in the latter. No major neurologic post-vaccination symptoms to either vaccine were reported in SGA infants or infants with PEM at the time of vaccination. No significant differences was noted in the incidence of major symptoms in PEM as compared with WN infants. One male infant (Group I) who was malnourished at birth and who had been given 2 doses of AOTP, developed clinical signs of pertussis infection between 2 and 4 months of age. Pertussis antibody levels immediately prior to infection were not significantly different from those of un infected age-matched cohorts. The percentage of infants afflicted with common childhood illnesses were similar in PEM and WN groups (46 vs. 43.2%) although the former group incurred significantly more illnesses at an earlier age' (s6 months) (p=O.05, chi square). These findings, albeit preliminary given the small numbers of subjects studied, suggest that acellular pertussis vaccine may be incorporated into routine vaccination schedules followed in developing countries with the expectation that adequate antibody responses will be provoked in SGA infants and in infants who develop post-natal PEM and that the incidence of vaccinerelated adverse effects will be no higher than in WN infants. Further and more extensive studies are indicated before the use of acellular pertussis vaccines can be recommended for routine primary vaccination of infants in preference to whole-cell preparations in developing countries. / Thesis (Ph.D.)-University of Natal, Durban, 1991.

Routinely collected data on vaccines supplied and administered, measles notifications and hospital admissions for measles were used to evaluate the 1990 measles immunisation campaign in Natal/KwaZulu. comparisons of the monthly averages during the 12 month period before the campaign, 4 months of the campaign and 12 months after the campaign indicated that the 1990 measles campaign in Natal/KwaZulu demonstrated that the campaign was limited, not by design, to blacks only. The campaign galvanised a high degree of participation from almost all health services in this region and resulted in a rapid and marked plunge in the incidence of measles as reflected by declines in both measles notifications and measles hospital admissions. There was no deleterious shortterm residual effect of the measles campaign on routine measles immunisation services. The spillover effects of the measles campaign on routine immunisation services against polio, tuberculosis and tetanus was generally beneficial. While the campaign was a success in generating involvement of health services in Natal/KwaZulu and reducing the burden of measles in this region, this disease has not been eliminated. Vigilance and continued routine vaccination efforts are required to prevent further epidemics of measles in Natal/KwaZulu. / Thesis (M.Med.)-University of Natal, 1990.

In dieser Arbeit wurde in einem Maus Tumormodell untersucht, ob durch eine intraoperative Vakzination mit gentechnisch modifizierten autologen Tumorzellen ein antitumoraler Effekt erzielt werden kann. Das Experiment erfolgte mit zwei Tumorzelllinien (B16 Melanom und Lewis Lung Karzinom). Nach Implantation der Tumorzellen in C57/BL 6 Mäuse wurden diese chirurgisch entfernt. Intraoperativ erhielten die Mäuse eine Vakzination. Dazu wurden folgende Impfstoffe verwendet: 1. subletal bestrahlte mIL-12 transfizierte Tumorzellen, 2. subletal bestrahlte pRSC transfizierte Tumorzellen und 3. frostgeschockte Tumorzellen. Die Impfung erfolgte entweder subcutan oder direkt in die Milz. Es wurde die Hypothese aufgestellt, dass eine Injektion in die Milz und eine Modifikation mit IL-12 den besten Effekt erzielt. Eine Kontrollgruppe blieb ohne Vakzin. Beobachtet wurde das Tumorwachstum, der Zeitpunkt bis zum makroskopischen Wiederauftreten eines Tumors, Überlebenszeit und die Metastasierungsrate. Versuchstiere ohne Rezidivtumor erhielten erneut einen Tumor. Es erfolgte eine erneute Evaluation des Tumorwachstums, des Zeitpunktes bis zum makroskopischen Wiederauftreten eines Tumors, der Überlebenszeit und der Metastasierungsrate. In beiden Tumorzelllinien profitierten alle Therapiegruppen nach Tumorresektion und Vakzination bezüglich Tumorrezidivrate, Zeit bis zum makroskopischenWiederauftreten des Tumors, Überlebenszeit, Metastasierungsrate und Tumorwachstumsgeschwindigkeit gegenüber der Kontrollgruppe. Vereinzelt konnten signifikante Vorteile für die direkt in die Milz applizierte Vakzine bezüglich der Tumorwachstumsgeschwindigkeit aufgezeigt werden. Weiterhin ergab sich eine geringere Tumorrezidivrate, wenn IL-12 modifizierte autologe Tumorzellen nach R0 Resektion direkt in die Milz appliziert wurden. Auch nach Tumorreimplantation konnte bezüglich Überlebenszeit und Tumorwachstumsgeschwindigkeit ein Vorteil für alle Therapiegruppen gegenüber der Kontrollgruppe herausgearbeitet werden. Nach Impfung in die Milz zeigte sich tendenziell eine geringere Metastasierungsrate. Intraoperative autologe Tumorzellvakzinationen konnten im Tiermodell in einem adjuvanten Setting einen antitumoralen Effekt auslösen. Möglicherweise kann diese Art der Impfung eine zusätzlich hilfreiche Behandlungsform zu den bisherigen adjuvanten Chemotherapeutika werden.

The lack of a vaccine candidate due to antigenic variation by trypanosomal parasites, the causative agents of human and animal African trypanosomiasis, requires the disease to be controlled by surveillance, diagnosis and appropriate treatment schedules. Due to the non-specific symptoms along with the toxicity and side effects of the current trypanocides, diagnosis needs to be accurate, cost effective and applicable to active case finding in mostly rural settings. Trypanosomal proteases have been identified as virulence factors as they are essential to the parasites‟ survival. Here the diagnostic potential of previously described virulence factors, oligopeptidase B (OPB), pyroglutamyl peptidase (PGP) and the full length and catalytic domain of the cathepsin L-like peptidases (CATLFL and CATL respectively) from T. congolense (Tc) as well as OPB and CATL from T. vivax (Tv), was determined. These antigens were recombinantly expressed, purified and used to generate antibodies in chickens. The purified recombinant antigens were tested in an inhibition and indirect ELISA format using two separate blinded serum panels consisting of sera from non-infected and experimentally infected cattle, one each for T. congolense and for T. vivax. The tested sera were diluted 1:10 for the TcCATLFL, TcCATL antigens whilst the TvCATL antigen used a 1:100 serum dilution. The TcCATLFL, TcCATL and TvCATL antigens had the highest diagnostic potential in the indirect ELISA format with a 90.91, 92.21% accuracy at the second cut-off and a 77.22% accuracy at the third cut-off along with 0.8084, 0.7785 and 0.8813 area under curve (AUC) values respectively. These antigens show potential for development of lateral flow tests to detect T. congolense and T. vivax infections in cattle. The recently discovered metacaspases (MCAs) have been implicated in caspase-like activity and differentiation in T. b. brucei, T. cruzi and L. major and are considered to be virulence factors. The putative metacaspase 5 gene from T. congolense (TcMCA5) was successfully cloned, expressed within inclusion bodies, resolubilised and refolded using immobilised metal affinity chromatography. Recombinant TcMCA5 was successfully refolded as evident by the hydrolysis of the synthetic peptide substrate, Z-Gly-Gly-Arg-AMC. Autocatalytic processing was observed within the inclusion bodies and the products were purified along with the full length recombinant protein. Anti-TcMCA5 IgY antibodies, raised in chickens, were able to detect the native TcMCA5 along with the autocatalytic processed products within the lysate of the procyclic T. congolense (strain IL 3000) parasites. The diagnostic potential of TcMCA5 still requires verification. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.

Background: Chronic HBV within the Canadian Arctic is considered endemic (>2% prevalence). To control endemic rates in Nunavut, a vaccination program was initiated approximately 20 years ago, targeted at newborns and grade school students, as an interim catch-up program, such that all individuals born after 1980 are potentially vaccinated. This study investigates the efficacy of these programs and is the first seroepidemiological survey to determine HBV prevalence in Nunavut in the post-vaccination era. Methods: Anonymized serum specimens scheduled for destruction following routine medical testing were collected from individuals granting consent. Specimens were tested for antibodies to HBV (anti-HBs, anti-HBc) and hepatitis C virus. Anti-HBc positive samples were further tested for surface antigen (HBsAg) positivity, and HBV DNA was extracted from HBsAg positive samples in order to perform molecular characterization. Results: 4802 specimens were collected according to the age distribution of Nunavut, with vaccine age cohort specimens comprising just over half of all collected specimens. Overall anti-HCV+ was 0.55%, with all positivity observed among those aged 24 to 69 years old. Total anti-HBc+ prevalence was 9.40%; however, a 10-fold decrease in the rate of HBV exposure was noted among those born after 1980 compared to those born before (1.89% vs 20.1%, p<0.001). HBsAg positivity was primarily documented in individuals born before 1980 (2.55%), although cases still occurred among the vaccine age cohort (0.21%). HBV subgenotype B5 (HBV/B5), known to be unique among Inuit and Alaska Native people, was the most prevalent genotype observed (82%). Vaccine-based antibody as the sole serological marker was evident in the vaccine age cohort, although the rate of decay with increasing age was much greater than anticipated. Conclusion: Nearly two decades after the advent of HBV vaccination in Nunavut, HBV prevalence has decreased to 1.17%, indicating a non-endemic or low risk prevalence. However, the persistence of infection and a lower than expected prevalence of vaccine-based immunity in the vaccine age cohort will require further investigation to understand the causes and consequences.

Despite the existence of effective vaccines for both diseases, measles and poliomyelitis still cause significant worldwide morbidity and mortality. The live-attenuated measles and inactivated polio vaccines are both given using a standard needle and syringe injection. This method of delivery poses many problems for large-scale vaccination campaigns. Microneedles are micron-scale needles which have the potential to overcome many of these hurdles. In the first study, we showed that the measles vaccine could be successfully incorporated into a solid, metal microneedle system which induced potent neutralizing antibody titers after administration into cotton rats. This response was statistically identical to the same dose delivered using a subcutaneous injection. The second study focused on enhancing the stability of the measles vaccine after drying and long-term storage. Using a new assay developed from a measles virus variant engineered to encode for green fluorescent protein, it was determined that a combination of sucrose and threonine provided the highest stabilizing effect. Vaccine mixed with this solution retained more than 90% of its activity after 6 months of storage at 4°C and 25°C. The third study involved the incorporation of the measles vaccine into a dissolving microneedle patch. These patches were used to vaccinate rhesus macaques and the immune response was found to be statistically identical to the same dose delivered by syringe injection. Furthermore, after creation and storage, these patches retained 100% of their infectivity after 2 months at 4°C and 25°C. The final study attempted to create a dissolving microneedle patch containing a full dose of the inactivated polio vaccine. These patches were then used to deliver a full dose of IPV into the skin of a rhesus macaque. This delivery method produced neutralizing antibody titers to IPV type 1 and 2 that were statistically identical to the same dose delivered using a needle and syringe. Overall, these studies show that the microneedle patch was a safe, simple and effective method for measles and polio vaccination. This delivery platform has the potential to overcome many of the hurdles that currently stand in the way of measles elimination and polio eradication.

No description available.