Unavailability Of Vaccine Research Articles

Evaluation of the Impact of Meningococcal Serogroup A Conjugate Vaccine Introduction on Second-Year-of-Life Vaccination Coverage in Burkina Faso.

After successful meningococcal serogroup A conjugate vaccine (MACV) campaigns since 2010, Burkina Faso introduced MACV in March 2017 into the routine Expanded Programme for Immunization schedule at age 15-18 months, concomitantly with second-dose measles-containing vaccine (MCV2). We examined MCV2 coverage in pre- and post-MACV introduction cohorts to describe observed changes regionally and nationally. A nationwide household cluster survey of children 18-41 months of age was conducted 1 year after MACV introduction. Coverage was assessed by verification of vaccination cards or recall. Two age groups were included to compare MCV2 coverage pre-MACV introduction (30-41 months) versus post-MACV introduction (18-26 months). In total, 15 925 households were surveyed; 7796 children were enrolled, including 3684 30-41 months of age and 3091 18-26 months of age. Vaccination documentation was observed for 86% of children. The MACV routine coverage was 58% (95% confidence interval [CI], 56%-61%) with variation by region (41%-76%). The MCV2 coverage was 62% (95% CI, 59%-65%) pre-MACV introduction and 67% (95% CI, 64%-69%) post-MACV introduction, an increase of 4.5% (95% CI, 1.3%-7.7%). Among children who received routine MACV and MCV2, 93% (95% CI, 91%-94%) received both at the same visit. Lack of caregiver awareness about the 15- to 18-month visit and vaccine unavailability were common reported barriers to vaccination. A small yet significant increase in national MCV2 coverage was observed 1 year post-MACV introduction. The MACV/MCV2 coadministration was common. Findings will help inform strategies to strengthen second-year-of-life immunization coverage, including to address the communication and vaccine availability barriers identified.

Vaccination status of patients using anti-TNF therapy and the physicians' behavior shaping the phenomenon: Mixed-methods approach.

ObjectiveAnti-tumor necrosis factor (Anti-TNF) therapy improves the prognosis and reduces the morbidity and mortality associated with many chronic inflammatory autoimmune diseases. However, as it is linked to an increased infection risk, appropriate vaccination is required. The study aimed at investigating the vaccination status of patients receiving Anti-TNF therapy and physicians’ perceptions of and views about vaccinating these patients.MethodsA sequential explanatory mixed-methods approach was used. The study comprised a quantitative, retrospective drug utilization review for determining institutional consumption of Anti-TNF therapy and an assessment of vaccination status in patients prescribed Anti-TNF therapy to audit physicians’ adherence to Anti-TNF therapy-related vaccination recommendations. Patient data from electronic medical records (EMRs) obtained from tertiary care hospitals between September 2015 and September 2017 were used. Further, a qualitative study using a phenomenographic approach with semi-structured interviews of 12 physicians was carried out to explore the physicians’ perceptions, views, and recommendations of vaccinating patients who are undergoing Anti-TNF therapy and identifying factors that may cause poor adherence to vaccination recommendations.ResultsForty-three of 310 patients receiving Anti-TNF therapy were vaccinated. Infliximab was the most frequently prescribed agent, accounting for 96.7% of total orders. Eight of the 12 physicians stated that they were aware of vaccination guidelines and seven viewed pre–Anti-TNF therapy vaccination as essential because of the high infection risk and claimed to incorporate it in their daily practice. Barriers to adherence included ignorance of recommendations, workload, vaccine unavailability, and advanced disease state.ConclusionAlthough the recommendations published by professional medical societies emphasized the importance of vaccination before initiating Anti-TNF therapy, few patients were vaccinated. Medical administration in hospitals should develop policies, procedures, and guidelines for vaccination; implement education programs for physicians and patients and procure vaccines in a timely way to improve their use.

HIV Vaccine Mystery and Viral Shell Disorder.

Hundreds of billions of dollars have been spent for over three decades in the search for an effective human immunodeficiency virus (HIV) vaccine with no success. There are also at least two other sexually transmitted viruses, for which no vaccine is available, the herpes simplex virus (HSV) and the hepatitis C virus (HCV). Traditional textbook explanatory paradigm of rapid mutation of retroviruses cannot adequately address the unavailability of vaccine for many sexually transmissible viruses, since HSV and HCV are DNA and non-retroviral RNA viruses, respectively, whereas effective vaccine for the horsefly-transmitted retroviral cousin of HIV, equine infectious anemia virus (EIAV), was found in 1973. We reported earlier the highly disordered nature of proteins in outer shells of the HIV, HCV, and HSV. Such levels of disorder are completely absent among the classical viruses, such as smallpox, rabies, yellow fever, and polio viruses, for which efficient vaccines were discovered. This review analyzes the physiology and shell disorder of the various related and non-related viruses to argue that EIAV and the classical viruses need harder shells to survive during harsher conditions of non-sexual transmissions, thus making them vulnerable to antibody detection and neutralization. In contrast, the outer shell of the HIV-1 (with its preferential sexual transmission) is highly disordered, thereby allowing large scale motions of its surface glycoproteins and making it difficult for antibodies to bind to them. The theoretical underpinning of this concept is retrospectively traced to a classical 1920s experiment by the legendary scientist, Oswald Avery. This concept of viral shapeshifting has implications for improved treatment of cancer and infections via immune evasion.

Uptake of immunization and associated factors among 0-11 months infants in a rural community of Ekiti State.

Background: Immunization is one of the most effective public health interventions, leading to reduced infant and childhood mortality caused by vaccine preventable diseases worldwide. Rates of vaccine preventable diseases have been observed to be decreasing in many parts of the world in the past few decades with many children still remain unvaccinated. Studies have shown that factors that are associated with immunization rates include; low family income, lack of health insurance, low level of parental education, religion, young age of parents, presence of other siblings in the household, lack of source of health care, distance to health facilities, place of delivery etc. The aim of this study is to determine the uptake of immunization and its associated factors among infants of a rural community inEkiti State. Methods: A systematic random sampling techniques was used to select 360 respondents from the rural Local Government Area whose mothers or caregivers were interviewed and vaccination cards observed to gather information on their immunization status. An interviewer administered semi-structured questionnaire and observational check-list were used to collect needed information. Descriptive analysis of findings was done using SPSS version 16. Results: Uptake of immunization by 0-11months children is relatively high in rural communities of Ekiti State (88.9%). The immunization card retention rate is also high (90%) and this is very good for authentic data gathering on routine immunization. The high uptake rate was found to be significantly associated with level of education, marital status and occupation. Healthcare workers and radio announcement still remain major sources of information on immunization; therefore attitude of health workers to clients is an important factor for uptake. Unavailability of vaccines, attitude of health workers and having no faith in immunization are important reasons for non-immunization. Conclusion: Uptake of immunization by children less than one year is relatively high in rural communities of Ekiti State (88.9%). The immunization card retention rate is also high (90%) and this is very good for authentic data gathering on routine immunization. Recommendation: Government to ensure regular, uninterrupted supply of vaccines to all points of vaccination to curb stock out, expand vaccination sites and centres to improve access and provide incentives to mothers/caregivers/families who completed their childhood immunization.

Factors associated with non-uptake of measles-rubella vaccine second dose among children under five years in Mtwara district council, Tanzania, 2017.

Introductionin 2014, Tanzania introduced the combined measles-rubella vaccine in the routine immunization schedule. Two doses of measles-rubella vaccine (MR1 and MR2) are recommended at 9 and 18 months, respectively. In 2015, MR2 coverage among eligible 18-month-old children in Tanzania was only 57%, lower than the WHO-recommended coverage (95%). During the same period Mtwara District Council (MDC) reported a coverage of 52% which is lower than the nation average. We determined factors associated with non-uptake of MR2 among children in MDC Tanzania.Methodswe conducted a community-based cross-sectional survey using cluster sampling during January - April 2017 in MDC. Caretakers of children born during January 2014 - January 2015 and residing in MDC for the past three years were recruited. We interviewed participants and reviewed vaccination cards. Logistic regression modeling was employed to identify independent factors associated with uptake of MR2.Resultsof 1,000 children assessed, 558 (55.8%) were unvaccinated with MR2. Factors independently associated with non-uptake of MR2 included the caretaker being unaware of the ages for MR1 and MR2 administration [aOR=3.50; 95%CI 1.98-6.21; p<0.001], having MR2 vaccination services offered at the local vaccination station fewer than three days per week [aOR=1.50; 95%CI 1.42-5.59; p<0.001], not having the vaccine available during vaccination days [aOR=3.38; 95%CI 1.08-10.61; p<0.01], unwillingness of health workers to open multi-dose vaccine vials for a single child [aOR=3.80; 95% CI 2.12-6.79; p<0.001], and long waiting times for vaccination services [aOR=1.80; 95% CI 1.08-3.00; p<0.01].Conclusionmore than half the children under five years in MDC were not vaccinated with MR2. Lack of caretaker knowledge about appropriate vaccination age, unavailability of vaccine, having insufficient numbers of children waiting to warrant multidose vial use, and long clinic waiting times were associated with MR2 non-uptake. The community should receive education about MR vaccine; we recommend thorough screening of children?s vaccination status at each clinic visit and provision of vaccine whenever possible. Vaccine distribution should be improved in MDC.

Towards a Strategy for Reducing Missed Opportunities for Vaccination in Malawi: Implications of a Qualitative Health Facility Assessment

Missed opportunities for vaccination (MOVs), estimated to be about 32-47% of child healthcare clinic visits in various settings globally, contribute to unfulfilled childhood vaccination coverage targets in the African region. We assessed the extent of MOVs, identify local drivers and test interventions to reduce MOVs in Malawi. We conducted in-depth and key informant interviews with administrators of district hospitals and officers in charge of community health facilities. Focus group discussions were held with health workers and caregivers of children under 24 months of age who received services from study health facilities in Malawi. Coverage rates were collected from the health facility records. Vaccination is appreciated in the communities, but coverage is generally below targets. In some facilities, reported coverage was less than 50%. Opportunities to provide up-to-date vaccination for children were missed due to lack of awareness and knowledge of health workers and caregivers, attitude and priority of health workers, long waiting time, poor coordination and referral of eligible children by clinicians and nurses and overall lack of a team approach to vaccination perceived as a responsibility of health surveillance assistants. Other notable issues included limited time of caregivers labouring on estate farms, unavailability of vaccines resulting from poorly functioning of cold chain equipment and limited transport and failure to appreciate the impact of MOV on poor immunization coverage. Simple, low-cost, pragmatic and community-driven interventions that may reduce MOVs and improve vaccine coverage.

Compliance to the National Immunization Program: A Review of Immunization Records of Grade 1 Students in a Public Elementary School in Manila for the Academic Year 2017-2018

Background: Vaccination is a cost-effective primary preventive measure against infectious diseases. However, protection for specific diseases may wane over time. The National Immunization Program was launched to improve vaccine coverage but despite this, some countries including the Philippines have erratic vaccine coverage. Objective: To determine the compliance to the National Immunization Program of Grade 1 students in a public elementary school Methodology: The study utilized a descriptive cross-sectional design. Simple random sampling of students enrolled in first grade for A.Y. 2017-2018 was done to determine the study respondents. Primary and secondary data were obtained through a pretested structured questionnaire with interview of the students’ caregiver and verification via the students’ immunization records. Compliance to immunization was correlated with the subjects’ age, birth rank, primary caregiver and socio-demographic profile of the caregiver, place of birth and place of vaccination. Data were analyzed using descriptive statistics and logistic regression was used to assess factors for increased vaccination compliance. Results: Most respondents had their mothers as primary caregivers. Majority were institutional deliveries and immunized at a health center. Mean compliance to vaccination was 69%. Among the factors, only place of birth, specifically, hospital delivery, was associated with increased compliance to vaccination (OR = 0.3312, 90% CI 0.1496 to 0.7333, p value 0.0064). Subjects whose primary caregivers were the mothers and whose parents had higher educational attainment or were both employed were shown to have higher vaccination compliance, although this was not statistically significant. Vaccination coverage was observed to decrease over time as the subjects grew older. Most common reasons cited for missing vaccinations were vaccine unavailability (68%), financial constraints 46%), and lack of information (40%). Conclusion: Compliance to vaccination in this study was 69% and is affected by multiple factors. Policymakers and stakeholders should address these barriers to improve vaccination coverage and overall health status.

Production and efficacy of a low-cost recombinant pneumococcal protein polysaccharide conjugate vaccine

Streptococcus pneumoniae is the leading cause of bacterial pneumonia. Although this is a vaccine preventable disease, S. pneumoniae still causes over 1 million deaths per year, mainly in children under the age of five. The biggest disease burden is in the developing world, which is mainly due to unavailability of vaccines due to their high costs. Protein polysaccharide conjugate vaccines are given routinely in the developed world to children to induce a protective antibody response against S. pneumoniae. One of these vaccines is Prevnar13, which targets 13 of the 95 known capsular types. Current vaccine production requires growth of large amounts of the 13 serotypes, and isolation of the capsular polysaccharide that is then chemically coupled to a protein, such as the diphtheria toxoid CRM197, in a multistep expensive procedure. In this study, we design, purify and produce novel recombinant pneumococcal protein polysaccharide conjugate vaccines in Escherichia coli, which act as mini factories for the low-cost production of conjugate vaccines. Recombinant vaccine efficacy was tested in a murine model of pneumococcal pneumonia; ability to protect against invasive disease was compared to that of Prevnar13. This study provides the first proof of principle that protein polysaccharide conjugate vaccines produced in E. coli can be used to prevent pneumococcal infection. Vaccines produced in this manner may provide a low-cost alternative to the current vaccine production methodology.

Chikungunya virus nsP1 interacts directly with nsP2 and modulates its ATPase activity

Chikungunya virus (CHIKV) is a mosquito-borne virus, which has created an alarming threat in the world due to unavailability of vaccine and antiviral compounds. The CHIKV nsP2 contains ATPase, RTPase, helicase and protease activities, whereas, nsP1 is a viral capping enzyme. In alphaviruses, the four non-structural proteins form the replication complex in the cytoplasm and this study characterizes the interaction between CHIKV nsP1 and nsP2. It was observed that, both the proteins co-localize in the cytoplasm and interact in the CHIKV infected cells by confocal microscopy and immunoprecipitation assay. Further, it was demonstrated through mutational analysis that, the amino acids 1-95 of nsP2 and 170-288 of nsP1 are responsible for their direct interaction. Additionally, it was noticed that, the ATPase activity of nsP2 is enhanced in the presence of nsP1, indicating the functional significance of this interaction. In silico analysis showed close (≤1.7 Å) polar interaction (hydrogen bond) between Glu4, Arg7, 96, 225 of nsP2 with Lys256, 206, Val367 and Phe312 of nsP1 respectively. Hence, this investigation provides molecular characterization of CHIKV nsP1-nsP2 interaction which might be a useful target for rational designing of antiviral drugs.

Immunization coverage in an urban resettlement colony of district Gautam-Budh Nagar, Uttar Pradesh, India using WHO 30×7 cluster sampling technique

Background: Immunization is one of the most cost-effective interventions to prevent the suffering that comes from avoidable sickness, disability and death. In India, though immunization coverage has improved over the past few years, the country still accounts for the largest number of children who are not immunized i.e. 7.4 million. So, this study was taken up to assess the immunization coverage among children in District Gautam-Budh Nagar of Uttar Pradesh and to decipher the causes behind the partial immunization/non- immunization. Methods: A cross-sectional study was conducted during June-August 2015 in an urban resettlement colony of District Gautam-Budh Nagar in Uttar Pradesh among 210 children aged 12-23 months selected using WHO 30X7 cluster sampling technique. Results: A total of 210 children were covered, of which 72.9% children were fully immunized, 19.0% children were partially immunized, whereas, 8.1% children did not receive even a single dose of any vaccine, thus constituting a total of 27.1% children with partial/no immunization. On bi-variate analysis, significant associ­ation was observed between immunization status among children and caste (p=0.047), mother’s education (p=0.01), father’s education (p=0.000) and socio-economic status (p=0.003). On multi-variate analysis, however, only father’s educational status was found to be significantly associated. The major reasons for partial/non-immunization among children were Ignorance (80.7%) followed by unavailability of vaccines (7.0%). Conclusions: Immunization coverage found in the present study is still way short of the target of universal coverage. Therefore, health planners and policy makers in our country should develop a comprehensive strategy to achieve universal immunization coverage.

Economic benefits of sharing and redistributing influenza vaccines when shortages occurred.

BackgroundRecurrent influenza outbreak has been a concern for government health institutions in Taiwan. Over 10% of the population is infected by influenza viruses every year, and the infection has caused losses to both health and the economy. Approximately three million free vaccine doses are ordered and administered to high-risk populations at the beginning of flu season to control the disease. The government recommends sharing and redistributing vaccine inventories when shortages occur. While this policy intends to increase inventory flexibility, and has been proven as widely valuable, its impact on vaccine availability has not been previously reported.Material and methodsThis study developed an inventory model adapted to vaccination protocols to evaluate government recommended polices under different levels of vaccine production. Demands were uncertain and stratified by ages and locations according to the demographic data in Taiwan.ResultsWhen vaccine supply is sufficient, sharing pediatric vaccine reduced vaccine unavailability by 43% and overstock by 54%, and sharing adult vaccine reduced vaccine unavailability by 9% and overstock by 15%. Redistributing vaccines obtained greater gains for both pediatrics and adults (by 75%). When the vaccine supply is in short, only sharing pediatric vaccine yielded a 48% reduction of unused inventory, while other polices do not improve performances.ConclusionsWhen implementing vaccination activities for seasonal influenza intervention, it is important to consider mismatches of demand and vaccine inventory. Our model confirmed that sharing and redistributing vaccines can substantially increase availability and reduce unused vaccines.

Parental factors affecting child's immunization status in Benghazi, Libya

Background: According to the World Health Organization recommendations, every country should have its own national immunization program for children to protect them against vaccines preventable diseases. This study aims to assess parental factors affecting the child's immunization status. Subjects and Methods: A descriptive, cross-sectional study was conducted on 419 parents attending maternal and child health (MCH) at El-hadaeq health center in Benghazi to vaccinate their children during November 1, 2016 to January 31, 2017. Results: Mothers constitute 79% of the study population and 53% of the children were male. Almost all the parents 402 (96%) were aware and had good knowledge about the national immunization program. Nearly 86% of the children were completely immunized for their age, and the main reason for missing vaccination is the unavailability of vaccines in MCH clinics. Conclusion: Although the awareness rate about immunization is high between the parents, there are still some children missed vaccinations. More educational interventions are therefore needed to increase and update parents' knowledge, and more emphasis on the local health authority is needed to ensure continuous vaccines supply to all MCH clinics and health centers in Libya.

Knowledge towards childhood immunization among mothers &amp; reasons for incomplete immunization

The objective of present study was to assess the knowledge towards childhood immunization among mothers and examining the reasons for incomplete immunization. A structured questionnaire was used to assess the knowledge of immunization among 377 mothers. Information regarding socio-demographic variables, gender disparity ratio, urban rural inequality ratio and reasons for incomplete immunization was collected from mothers bearing children of age 3 years. Around 115 (30.50%) children were partially immunized. Unavailability of vaccine was found to be the major reason for incomplete immunization. The association between gender and immunization status was found to be statistically significant (p=0.027).The association between mother’s education and knowledge score was statistically significant in our study (p=0. 005). A statistically significant association was found between area of residence and knowledge score towards immunization in our study (p=0.001). Mother’s education and area of residence was found to get associated with knowledge of immunization. However, knowledge towards immunization and immunization status was not significantly associated. It shows a very good progression regarding awareness of immunization. In recent days electronic media and anganwadi worker’s efforts in raising consciousness about the importance of immunization might increase the immunization rate irrespective of knowledge and area of residence of people.

Rubella and CMV Antibodies Screening During Pregnancy - A Retrospective Study in a Tertiary Hospital

Background: In India, RUBELLA & CMV Antibodies screening is routinely carried out, but due to absence of clear intervention, its value is questionable. This retrospective study evaluated the usefulness of rubella & cmv antibody screening during pregnancy. Methods: Blood is collected from pregnant women & children, tested for rubella and CMV specific IgM Antibody by capture ELISA. The data were analysed to determine the incidence of rubella &CMV infection during pregnancy & in congenital infections. Results: In asymptomatic pregnancy females (n=252) rubella positivity was 1.58% and in woman with BOH (n=110) it was 3.66%, while CMV passivity was 2.9% in both asymptomatic and BOH women. In children (n=100) the overall positivity for rubella and CMV specific IgM antibodies was 7.5% and 12.5% respectively. The incidence of rubella and CMV infections in pregnant women & women with BOH has declined. In children, also the congenital rubella syndrome has declined but for the past 5 years the incidence of CMV infection remained same without any change. Conclusions: The incidence of rubella over the past 5 years can be reduced after giving the rubella vaccine to school going girls & women with reproductive age apart from routine vaccine. But CMV infection is a big problem due to unavailability of vaccine & safe treatment against CMV infection, so routine screening for rubella and CMV should be reserved for women with obstetric complications only.

Simultaneous Deletion of the 9GL and UK Genes from the African Swine Fever Virus Georgia 2007 Isolate Offers Increased Safety and Protection against Homologous Challenge.

Currently, there is no commercially available vaccine against African swine fever. Outbreaks of the disease are devastating to the swine industry and are caused by circulating strains of African swine fever virus. Here, we report a putative vaccine derived from a currently circulating strain but containing two deletions in two separate areas of the virus, allowing increased safety. Using this genetically modified virus, we were able to vaccinate swine and protect them from developing ASF. We were able to achieve protection from disease as early as 2 weeks after vaccination, even when the pigs were exposed to a higher than normal concentration of ASFV.

Computational prediction and analysis of potential antigenic CTL epitopes in Zika virus: A first step towards vaccine development

The Zika virus disease is an Aedes mosquito-borne disease caused by the ZIKA virus. The unavailability of vaccines or proper chemotherapeutic treatment emphasizes the need for the development of preventive and therapeutic vaccines. T cell specific epitopes have been used as vaccine candidates to generate desired immune responses against a variety of viral pathogens. Herein, the immune-informatics approach was used for the screening of potential major histocompatibility complex class I restricted epitopes, which may be competent to generate a cell-mediated immune response in humans. A total of 63 epitopes were identified, which revealed a comprehensive binding affinity to the 42 different human leukocyte antigen class I supertypes: A01, A02, A08, A23, A24, A25, A26, A29, A30, A32, A66, A68, A69, A80, B07, B08, B14, B15, B27, B35, B39, B40, B42, B45, B46, B48, B51, B53, B54, B57, B58, B83, C12, C03, C04, C05, C06, C07, C08, C12, C14, and C15, and which had no homologs in humans. By combining the human leukocyte antigen binding specificity and population coverage, nine promiscuous epitopes located in Capsid 1 Protein (MVLAILAFL(P1)), Envelop Protein (RLKGVSYSL (P2) and RLITANPVI (P3)), NS2A (AILAALTPL (P4)), NS4B (LLVAHYMYL (P5) and LVAHYMYLI (P6)) and NS5 (SLINGVVRL (P7), ALNTFTNLV (P8) and YLSTQVRYL (P9)) were shortlisted. Most of these consensus epitopes revealed 100% conservancy in all Zika virus strains and were very less conserved against the human proteome. The combination of the selected epitopes accounted for an optimal coverage in the world wide population (>99%) independent of ethnicity. Structural analysis of these selected epitopes by the PatchDock web server showed their preferential mode of presentation to the T cell receptor. All these results recommended the possibility of a combined epitope vaccine strategy and can therefore be further investigated for their immunological relevance and usefulness as vaccine candidates.

UDP-galactopyranose mutase, a potential drug target against human pathogenic nematode Brugia malayi.

Lymphatic filariasis, a vector-borne neglected tropical disease affects millions of population in tropical and subtropical countries. Vaccine unavailability and emerging drug resistance against standard antifilarial drugs necessitate search of novel drug targets for developing alternate drugs. Recently, UDP-galactopyranose mutases (UGM) have emerged as a promising drug target playing an important role in parasite virulence and survival. This study deals with the cloning and characterization of Brugia malayi UGM and further exploring its antifilarial drug target potential. The recombinant protein was actively involved in conversion of UDP-galactopyranose (substrate) to UDP-galactofuranose (product) revealing Km and Vmax to be ∼51.15μM and ∼1.27μM/min, respectively. The purified protein appeared to be decameric in native state and its 3D homology modeling using Aspergillus fumigatus UGM enzyme as template revealed conservation of active site residues. Two specific prokaryotic inhibitors (compounds A and B) of the enzyme inhibited B. malayi UGM enzymatic activity competitively depicting Ki values ∼22.68 and ∼23.0μM, respectively. These compounds were also active in vitro and in vivo against B. malayi The findings suggest that B. malayi UGM could be a potential antifilarial therapeutic drug target.

African swine fever virus Georgia isolate harboring deletions of 9GL and MGF360/505 genes is highly attenuated in swine but does not confer protection against parental virus challenge

African swine fever virus (ASFV) produces a contagious disease of domestic pigs that results in severe economic consequences to the swine industry. Control of the disease has been hampered by the unavailability of vaccines. We recently reported the development of two experimental vaccine strains (ASFV-G-Δ9GL and ASFV-G-ΔMGF) based on the attenuation of the highly virulent and epidemiologically relevant Georgia2007 isolate. Deletion of the 9GL gene or six genes of the MGF360/505 group produced two attenuated ASFV strains which were able to confer protection to animals when challenged with the virulent parental virus. Both viruses, although efficient in inducing protection, present concerns regarding their safety. In an attempt to solve this problem we developed a novel virus strain, ASFV-G-Δ9GL/ΔMGF, based on the deletion of all genes deleted in ASFV-G-Δ9GL and ASFV-G-ΔMGF. ASFV-G-Δ9GL/ΔMGF is the first derivative of a highly virulent ASFV field strain subjected to a double round of recombination events seeking to sequentially delete specific genes. ASFV-G-Δ9GL/ΔMGF showed a decreased ability to replicate in primary swine macrophage cultures relative to that of ASFV-G and ASFV-G-ΔMGF but similar to that of ASFV-G-Δ9GL. ASFV-G-Δ9GL/ΔMGF was attenuated when intramuscularly inoculated into swine, even at doses as high as 106 HAD50. Animals infected with doses ranging from 102 to 106 HAD50 did not present detectable levels of virus in blood at any time post-infection and they did not develop detectable levels of anti-ASFV antibodies. Importantly, ASFV-G-Δ9GL/ΔMGF does not induce protection against challenge with the virulent parental ASFV-G isolate. Results presented here suggest caution towards approaches involving genomic manipulations when developing rationally designed ASFV vaccine strains.

Factors associated with incomplete childhood immunization in Arbegona district, southern Ethiopia: a case--control study.

BackgroundThe prevention of child mortality through immunization is one of the most cost-effective and widely applied public health interventions. In Ethiopia, the Expanded Program on Immunization (EPI) schedule is rarely completed as planned and the full immunization rate is only 24 %. The objective of this study was to identify determinant factors of incomplete childhood immunization in Arbegona district, Sidama zone, southern Ethiopia.MethodsA community based unmatched case-control study was undertaken among randomly selected children aged 12 to 23 months and with a total sample size of 548 (183 cases and 365 controls). A multi-stage sampling technique was used to get representative cases and controls. Data was collected using a structured questionnaire and analyzed using SPSS version 16 statistical software. Bivariate and multiple logistic regression analyses were done to identify independent factors for incomplete immunization status of children. Qualitative data were also generated and analyzed using thematic framework.ResultsThe incomplete immunization status of children was significantly associated with young mothers (AOR = 9.54; 95 % CI = 5.03, 18.09), being born second to fourth (AOR = 3.64; 95 % CI = 1.63, 8.14) and being born fifth or later in the family (AOR = 5.27; 95 % CI = 2.20, 12.64) as compared to being born first, a mother’s lack of knowledge about immunization benefits (AOR = 5.51; 95 % CI = 1.52, 19.94) and a mother’s negative perception of vaccine side effects (AOR = 1.92; 95 % CI = 1.01, 3.70). The qualitative finding revealed that the migration of mothers and unavailability of vaccines on appointed immunization dates were the major reasons for partial immunization of children.ConclusionTo reduce the number of children with incomplete immunization status, the Arbegona district needs to consider specific planning for mothers with these risk profiles. A focus on strengthening health communication activities to raise immunization awareness and address concerns of vaccine side effects at community level is also needed. This could be achieved through integrating the immunization service to other elements of primary health care.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-015-2678-1) contains supplementary material, which is available to authorized users.

Convalescent plasma: new evidence for an old therapeutic tool?

Passive immunisation for the prevention and treatment of human infectious diseases can be traced back to the 20(th) century. The recent Ebola virus outbreak in West Africa has turned the spotlight onto the possible use of convalescent whole blood and convalescent plasma in the treatment of infectious diseases because they are the only therapeutic strategy available in some cases, given the unavailability of vaccines, drugs or other specific treatments. Convalescent blood products could be a valid option in the treatment/prophylaxis of several infectious diseases both in association with other drugs/preventive measures and as the only therapy when a specific treatment is not available. However, there are still some issues to consider in determining the advisability of implementing a large-scale convalescent plasma transfusion programme.