Displaying publications 141 - 160 of 205 in total

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  1. Fulltext Protection against henipaviruses in swine requires both, cell-mediated and humoral immune response
    Pickering BS, Hardham JM, Smith G, Weingartl ET, Dominowski PJ, Foss DL, et al.
    Vaccine, 2016 09 14;34(40):4777-86.
    PMID: 27544586 DOI: 10.1016/j.vaccine.2016.08.028
    Hendra virus (HeV) and Nipah virus (NiV) are members of the genus Henipavirus, within the family Paramyxoviridae. Nipah virus has caused outbreaks of human disease in Bangladesh, Malaysia, Singapore, India and Philippines, in addition to a large outbreak in swine in Malaysia in 1998/1999. Recently, NiV was suspected to be a causative agent of an outbreak in horses in 2014 in the Philippines, while HeV has caused multiple human and equine outbreaks in Australia since 1994. A swine vaccine able to prevent shedding of infectious virus is of veterinary and human health importance, and correlates of protection against henipavirus infection in swine need to be better understood. In the present study, three groups of animals were employed. Pigs vaccinated with adjuvanted recombinant soluble HeV G protein (sGHEV) and challenged with HeV, developed antibody levels considered to be protective prior to the challenge (titers of 320). However, activation of the cell-mediated immune response was not detected, and the animals were only partially protected against challenge with 5×10(5) PFU of HeV per animal. In the second group, cross-neutralizing antibody levels against NiV in the sGHEV vaccinated animals did not reach protective levels, and with no activation of cellular immune memory, these animals were not protected against NiV. Only pigs orally infected with 5×10(4) PFU of NiV per animal were protected against nasal challenge with 5×10(5) PFU of NiV per animal. This group of pigs developed protective antibody levels, as well as cell-mediated immune memory. Peripheral blood mononuclear cells restimulated with UV-inactivated NiV upregulated IFN-gamma, IL-10 and the CD25 activation marker on CD4(+)CD8(+) T memory helper cells and to lesser extent on CD4(-)CD8(+) T cells. In conclusion, both humoral and cellular immune responses were required for protection of swine against henipaviruses.
    Matched MeSH terms: Viral Vaccines/immunology*
  2. Fulltext Development of standard clinical endpoints for use in dengue interventional trials
    Tomashek KM, Wills B, See Lum LC, Thomas L, Durbin A, Leo YS, et al.
    PLoS Negl Trop Dis, 2018 10;12(10):e0006497.
    PMID: 30286085 DOI: 10.1371/journal.pntd.0006497
    Dengue is a major public health problem worldwide. Although several drug candidates have been evaluated in randomized controlled trials, none has been effective and at present, early recognition of severe dengue and timely supportive care are used to reduce mortality. While the first dengue vaccine was recently licensed, and several other candidates are in late stage clinical trials, future decisions regarding widespread deployment of vaccines and/or therapeutics will require evidence of product safety, efficacy and effectiveness. Standard, quantifiable clinical endpoints are needed to ensure reproducibility and comparability of research findings. To address this need, we established a working group of dengue researchers and public health specialists to develop standardized endpoints and work towards consensus opinion on those endpoints. After discussion at two working group meetings and presentations at international conferences, a Delphi methodology-based query was used to finalize and operationalize the clinical endpoints. Participants were asked to select the best endpoints from proposed definitions or offer revised/new definitions, and to indicate whether contributing items should be designated as optional or required. After the third round of inquiry, 70% or greater agreement was reached on moderate and severe plasma leakage, moderate and severe bleeding, acute hepatitis and acute liver failure, and moderate and severe neurologic disease. There was less agreement regarding moderate and severe thrombocytopenia and moderate and severe myocarditis. Notably, 68% of participants agreed that a 50,000 to 20,000 mm3 platelet range be used to define moderate thrombocytopenia; however, they remained divided on whether a rapid decreasing trend or one platelet count should be case defining. While at least 70% agreement was reached on most endpoints, the process identified areas for further evaluation and standardization within the context of ongoing clinical studies. These endpoints can be used to harmonize data collection and improve comparability between dengue clinical trials.
    Matched MeSH terms: Dengue Vaccines/immunology
  3. High Prevalence of Human Papillomavirus Types 56 and 70 Identified in the Native Populations of Sabah, Malaysia
    Sainei NE, Kumar VS, Chin YS, Salih FAM
    Asian Pac J Cancer Prev, 2018 Oct 26;19(10):2807-2813.
    PMID: 30360610
    Background: Cervical cancer is currently the third most common female cancer in Malaysia , with the human
    papillomavirus (HPV) considered as one of the important contributory factors. This study was conducted to determine
    HPV prevalence, its genotype distribution, and other potential risk factors among women in Kota Kinabalu, Sabah
    in order to evaluate the likely efficacy of current HPV vaccines in the local population. Methods: A total of 240
    cervical samples were collected and subjected to DNA extraction, PCR amplification using the MY09/MY11 primer
    pair, and restriction fragment length polymorphism (RFLP) for HPV detection and genotyping. Sociodemographic,
    clinical, and behavioural data were also collected via questionnaires. Results: The prevalence of HPV infection was
    9.6%. The most common HPVs among 13 genotypes were high-risk HPV-56 (16.7%) and probable high-risk HPV-70
    (16.7%) followed by HPV-16, -58, -53, -61, -33, -59, and -66 (in decreasing order of prevalence) including the rare
    genotypes: HPV-62, -81, -82 and -84. Statistical analyses using logistic regression models showed that HPV infection
    was significantly associated with employment (OR 4.94; CI 1.58-15.40) and education at secondary/high school level
    (OR 0.13; CI 0.03-0.62). Conclusion: Distribution of HPV genotypes in Sabah indicated a high prevalence of HPV-56
    and -70 which are among the rare HPV types in West Malaysia and merit consideration in future strategies for HPV
    vaccination specifically for local Sabahan women.
    Matched MeSH terms: Papillomavirus Vaccines/immunology
  4. Antigenic potential of a recombinant polyvalent DNA vaccine against pathogenic leptospiral infection
    Garba B, Bahaman AR, Zakaria Z, Bejo SK, Mutalib AR, Bande F, et al.
    Microb Pathog, 2018 Nov;124:136-144.
    PMID: 30138761 DOI: 10.1016/j.micpath.2018.08.028
    Leptospirosis is a serious epidemic disease caused by pathogenic Leptospira species. The disease is endemic in most tropical and sub-tropical regions of the world. Currently, there is no effective polyvalent vaccine for prevention against most of the circulating serovars. Moreover, development of an efficient leptospiral vaccine capable of stimulating cross-protective immune responses against a wide range of serovars remains a daunting challenge. This, in part, is associated with the extensive diversity and variation of leptospiral serovars from region to region. In this study, a multi-epitope DNA vaccine encoding highly immunogenic epitopes from LipL32 and LipL41 was designed using in-silico approach. The DNA encoding antigenic epitopes was constructed from conserved pathogenic Leptospira genes (LipL32 and LipL41). Immunization of golden Syrian hamsters with the multi-epitope chimeric DNA vaccine resulted in the production of both agglutinating and neutralizing antibodies as evidence by MAT and in-vitro growth inhibition tests respectively. The antibodies produced reacted against eight different serovars and significantly reduced renal colonization following in vivo challenge. The vaccine was also able to significantly reduce renal colonization which is a very important factor responsible for persistence of leptospires among susceptible and reservoir animal hosts. In conclusion, the leptospiral multi-epitope chimeric DNA vaccine can serve as a potentially effective and safe vaccine against infection with different pathogenic leptospiral serovars.
    Matched MeSH terms: Bacterial Vaccines/immunology*
  5. Fulltext In vitro evaluation of dual-antigenic PV1 peptide vaccine in head and neck cancer patients
    Chai SJ, Fong SCY, Gan CP, Pua KC, Lim PVH, Lau SH, et al.
    Hum Vaccin Immunother, 2019;15(1):167-178.
    PMID: 30193086 DOI: 10.1080/21645515.2018.1520584
    Peptide vaccines derived from tumour-associated antigens have been used as an immunotherapeutic approach to induce specific cytotoxic immune response against tumour. We previously identified that MAGED4B and FJX1 proteins are overexpressed in HNSCC patients; and further demonstrated that two HLA-A2-restricted 9-11 amino acid peptides derived from these proteins were able to induce anti-tumour immune responses in vitro independently using PBMCs isolated from these patients. In this study, we evaluated the immunogenicity and efficacy of a dual-antigenic peptide vaccine (PV1), comprised of MAGED4B and FJX1 peptides in HNSCC patients. We first demonstrated that 94.8% of HNSCC patients expressed MAGED4B and/or FJX1 by immunohistochemistry, suggesting that PV1 could benefit the majority of HNSCC patients. The presence of pre-existing MAGED4B and FJX1-specific T-cells was detected using a HLA-A2 dimer assay and efficacy of PV1 to induce T-cell to secrete cytotoxic cytokine was evaluated using ELISPOT assay. Pre-existing PV1-specific T-cells were detected in all patients. Notably, we demonstrated that patients' T-cells were able to secrete cytotoxic cytokines upon exposure to target cells expressing the respective antigen post PV1 stimulation. Furthermore, patients with high expression of MAGED4B and FJX1 in their tumours were more responsive to PV1 stimulation, demonstrating the specificity of the PV1 peptide vaccine. Additionally, we also demonstrated the expression of MAGED4B and FJX1 in breast, lung, colon, prostate and rectal cancer suggesting the potential use of PV1 in these cancers. In summary, PV1 could be a good vaccine candidate for the treatment of HNSCC patients and other cancers expressing these antigens.
    Matched MeSH terms: Cancer Vaccines/immunology*
  6. Awareness and perception of seasonal influenza (Flu) among health science and Non-Health science university students in Pakistan: A nationwide survey
    Bukhsh A, Hussain S, Rehman IU, Mallhi TH, Khan YH, Khaliel AM, et al.
    Pak J Pharm Sci, 2019 Jul;32(4(Supplementary)):1789-1796.
    PMID: 31680074
    Seasonal influenza is a highly contagious viral respiratory disorder. Prior knowledge of flu among general community is of paramount importance in order to mitigate its growing burden. In a pandemic, young adults are more likely to be infected increasing the potential for universities to be explosive disease outbreak centers. In this context, current study aims to assess the knowledge and perception of flu among university students from health sciences (HS) and non-HS background. Questionnaire-based cross sectional (August-December 2015) study was conducted among students of 65 universities across Pakistan. The students willing to participate were requested to fill out the self-administered questionnaire and responses were recorded and descriptively analyzed by SPSS. A total of 1694 students (age: 21.12 ± 2.13 years), 95% which belonged to age group 18-25 years, participated in the current study. Most of the participants (91.7%) had suffered from influenza during their life but only 55.7% correctly answered virus as causative agent of flu, while majority of participants, primarily from non-HS disciplines were not aware of flu cause. Very few participants (8.1%) believed that flu can cause death. About 20% students, mainly from non-HS disciplines reported that antibiotic can kill viruses. Similarly, 47.1% respondents agreed on the effectiveness of antibiotic in flu. A large proportion of study population preferred self-medication for influenza. Only 20.1% students were aware of influenza vaccine while majority of students (79.9%) from both disciplines reported that there is no such vaccine. Awareness and health literacy regarding seasonal influenza is poor among university students, especially from non-HS disciplines. These findings necessitate dire need to appropriately structured awareness programs in educational institutes to curb the growing burden of influenza.
    Matched MeSH terms: Influenza Vaccines/immunology
  7. Immunohistochemical, histological and ultrastructural evaluation of protection provided by cholera vaccine against V. cholerae O139
    Murugaiah C, Nik Mohd Noor NZ, Al-Talib H, Mustafa S, Manickam R, Pattabhiraman L
    Microb Pathog, 2020 Mar;140:103964.
    PMID: 31904450 DOI: 10.1016/j.micpath.2020.103964
    In our previous study, complete protection was observed in rabbit immunized with 1 × 1010 CFU of live attenuated VCUSM21P vaccine against challenge with 1 × 109 CFU Vibrio cholerae O139. In the present study, we investigated whether the vaccines can effectively protect immunized animals from any pathologic changes using histological, immunohistochemical and ultrastructural techniques. Severe pathology is evident in wild type injected ileum in non-immunized, showing extensive villous destruction, edema, necrosis and inflammation with infiltration of large numbers of inflammatory cells, extensive damage to the villi and microvilli with pore formation. Histology of ileum injected with wild type in immunized rabbit shows no significant pathological changes except for a few inflammatory cells in lamina propria with mild edema in mucosa and submucosa. immunohistochemical staining revealed O139 antigens of wild type are seen in the lamina propria of edematous villi, muscularis mucosa and submucosa with weak presence in the muscle coat in non-immunized rabbit after challenged with wild type in non-immunized rabbits, but in immunized rabbit localisation of the O139 LPS antigen is seen at the tips of the intact villi, within lamina propria and muscularis mucosa only. These observations suggest that the vaccine can effectively protect animals from any pathologic changes and eliminate V. cholerae O139 from the immunized animals.
    Matched MeSH terms: Cholera Vaccines/immunology
  8. Incidence rates of neurotropic-like and viscerotropic-like disease in three dengue-endemic countries: Mexico, Brazil, and Malaysia
    Cohen C, Moreira ED, Nañez H, Nachiappan JP, Arvinder-Singh HS, Huoi C, et al.
    Vaccine, 2019 03 22;37(13):1868-1875.
    PMID: 30826144 DOI: 10.1016/j.vaccine.2019.01.087
    BACKGROUND: The background incidence of viscerotropic- (VLD) and neurotropic-like disease (NLD) unrelated to immunization in dengue-endemic countries is currently unknown.

    METHODS: This retrospective population-based analysis estimated crude and standardized incidences of VLD and NLD in twelve hospitals in Brazil (n = 3), Mexico (n = 3), and Malaysia (n = 6) over a 1-year period before the introduction of the tetravalent dengue vaccine. Catchment areas were estimated using publicly available population census information and administrative data. The denominator population for incidence rates was calculated, and sensitivity analyses assessed the impact of important assumptions.

    RESULTS: Total cases adjudicated as definite VLD were 5, 57, and 56 in Brazil, Mexico, and Malaysia, respectively. Total cases adjudicated as definite NLD were 103, 29, and 26 in Brazil, Mexico, and Malaysia, respectively. Crude incidence rates of cases adjudicated as definite VLD in Brazil, Mexico, and Malaysia were 1.17, 2.60, and 1.48 per 100,000 person-years, respectively. Crude incidence rates of cases adjudicated as definite NLD in Brazil, Mexico, and Malaysia were 4.45, 1.32, and 0.69 per 100,000 person-years, respectively.

    CONCLUSIONS: Background incidence estimates of VLD and NLD obtained in Mexico, Brazil, and Malaysia could provide context for cases occurring after the introduction of the tetravalent dengue vaccine.

    Matched MeSH terms: Dengue Vaccines/immunology
  9. Fulltext The Conserved Molecular Determinants of Virulence in Dengue Virus
    Ahmad Z, Poh CL
    Int J Med Sci, 2019;16(3):355-365.
    PMID: 30911269 DOI: 10.7150/ijms.29938
    Dengue virus belongs to the Flaviviridae family which also includes viruses such as the Zika, West Nile and yellow fever virus. Dengue virus generally causes mild disease, however, more severe forms of the dengue virus infection, dengue haemorrhagic fever (DHF) and dengue haemorrhagic fever with shock syndrome (DSS) can also occur, resulting in multiple organ failure and even death, especially in children. The only dengue vaccine available in the market, CYD-TDV offers limited coverage for vaccinees from 9-45 years of age and is only recommended for individuals with prior dengue exposure. A number of mutations that were shown to attenuate virulence of dengue virus in vitro and/or in vivo have been identified in the literature. The mutations which fall within the conserved regions of all four dengue serotypes are discussed. This review hopes to provide information leading to the construction of a live attenuated dengue vaccine that is suitable for all ages, irrespective of the infecting dengue serotype and prior dengue exposure.
    Matched MeSH terms: Dengue Vaccines/immunology
  10. Evaluation of bovine antibody responses to haemorrhagic septicaemia vaccine
    Johnson RB, Dawkins HJ, Spencer TL, Saharee AA, Bahaman AR, Ramdani, et al.
    Res Vet Sci, 1989 Sep;47(2):277-9.
    PMID: 2508206
    ELISA and immunoblotting techniques were used to examine the humoral immune response to Pasteurella multocida, in bovine sera from Indonesia and Malaysia. Elevated levels of antibody to a crude lipopolysaccharide preparation were found in vaccinated animals. In addition to the response to lipopolysaccharide, antibodies from the vaccinated cattle strongly labelled five to six of the 40 protein bands in this organism.
    Matched MeSH terms: Bacterial Vaccines/immunology*
  11. Fulltext Immunogenicity and Safety of a Tetravalent Dengue Vaccine Administered Concomitantly or Sequentially With Quadrivalent Human Papillomavirus Vaccine in Boys and Girls 9-13 Years of Age in Malaysia: A Phase IIIb, Randomized, Open-label Study
    Hassan J, Toh TH, Sivapunniam SK, Hasim R, Ghazali NF, Sulaiman S, et al.
    Pediatr Infect Dis J, 2021 08 01;40(8):774-781.
    PMID: 34250977 DOI: 10.1097/INF.0000000000003164
    BACKGROUND: Incorporating dengue vaccination within existing vaccination programs could help improve dengue vaccine coverage. We assessed the immunogenicity and safety of a quadrivalent human papillomavirus (HPV) vaccine administered concomitantly or sequentially with a tetravalent dengue vaccine (CYD-TDV) in healthy children 9-13 years of age in Malaysia.

    METHODS: In this phase IIIb, open-label, multicenter study (NCT02993757), participants were randomized 1:1 to receive 3 CYD-TDV doses 6 months apart and 2 doses of quadrivalent HPV vaccine concomitantly with, or 1 month before (sequentially), the first 2 CYD-TDV doses. Only baseline dengue-seropositive participants received the 3 doses. Antibody levels were measured at baseline and 28 days after each injection using an enzyme-linked immunosorbent assay for HPV-6, -9, -16 and -18, and the 50% plaque reduction neutralization test for the 4 dengue serotypes; immunogenicity results are presented for baseline dengue-seropositive participants. Safety was assessed throughout the study for all participants.

    RESULTS: At baseline, 197 of 528 (37.3%) randomized participants were dengue-seropositive [n = 109 (concomitant group) and n = 88 (sequential group)]. After the last HPV vaccine dose, antibody titers for HPV among baseline dengue-seropositive participants were similar between treatment groups, with between-group titer ratios close to 1 for HPV-6 and 0.8 for HPV-11, -16, and -18. After CYD-TDV dose 3, dengue antibody titers were similar between treatment groups for all serotypes [between-group ratios ranged from 0.783 (serotype 2) to 1.07 (serotype 4)]. No safety concerns were identified.

    CONCLUSIONS: The immunogenicity and safety profiles of CYD-TDV and quadrivalent HPV vaccines were unaffected when administered concomitantly or sequentially in dengue-seropositive children.

    Matched MeSH terms: Dengue Vaccines/immunology
  12. Fulltext Knowledge, attitudes, and perception towards human papillomavirus among university students in Pakistan
    Khan TM, Buksh MA, Rehman IU, Saleem A
    Papillomavirus Res, 2016 12;2:122-127.
    PMID: 29074171 DOI: 10.1016/j.pvr.2016.06.001
    This cross-sectional study comprises a questionnaire-based survey regarding knowledge about human papillomavirus and its vaccine among students in different educational fields at public and private universities in the city of Lahore in Pakistan. A 26-item questionnaire was used to attain the objective of this study. The reliability of this tool was assessed using Cronbach's alpha (0.79) and the Kaiser-Meyer-Olkin value was 0.827. The response rate to the survey was 78.0%, of whom the majority (74.9%) were females and 308 (79%) were single (median age=23 years). While assessing the respondents' knowledge about HPV, 223(57%) students reported that they had already heard of HPV (human papillomavirus) and nearly 215 (55%) reported that HPV causes cervical cancer and can infect both men and women. Gender and field of study were two main factors found influencing the respondents' knowledge about HPV. Moreover, students' understanding about the mode of transmission of HPV was cursory: 40.51% said they did not know how HPV is transmitted, 133 (34.10%) stated that HPV spreads through the exchange of bodily fluids, and 22 (5.64%) selected cough/sneezing. In terms of prevention, 175 (44.87%) students stated that HPV can be prevented by vaccination, 30.0% reported sexual abstinence, 21.54% using condoms, and nearly 5.38% disclosed use of antibiotics. Addressing the knowledge of students regarding HPV vaccine, nearly 53% stated there is no vaccine against HPV and almost 64% rejected the statement that HPV vaccine prevents cervical cancer. In addition, students reported that they will be more than willing to get vaccinated for HPV if their physician recommend them (RII=0.74) followed by parents (RII=0.69). The results of this study revealed a poor understanding among respondents about the health problems associated with HPV, its prevention, modes of transmission and arability of HPV vaccine in Pakistan.
    Matched MeSH terms: Papillomavirus Vaccines/immunology*
  13. Development of Novel miRNA-based Vaccines and Antivirals against Enterovirus 71
    Yee PT, Poh CL
    Curr Pharm Des, 2016;22(44):6694-6700.
    PMID: 27510488 DOI: 10.2174/1381612822666160720165613
    The Hand, Foot and Mouth Disease (HFMD) is caused by Enterovirus 71 (EV-A71) and Coxsackieviruses. Common HFMD symptoms are high fever (≥ 39°C), rashes, and ulcers but complications due to virulent EV-A71 may arise leading to cardiopulmonary failure and death. The lack of vaccines and antiviral drugs against EV-A71 highlights the urgency of developing preventive and treatment agents. Recent studies have reported the emergence of novel antiviral agents and vaccines that utilize microRNAs (miRNAs). They belong to a class of small (19-24 nt) non coding RNA molecules. As miRNAs play a major role in the host regulatory system, there is a huge opportunity for interplay between host miRNAs and EV-A71 expressions. A total of 42 out of 64 miRNAs were up-regulated in EV-A71-infected cells. There was consistent up-regulation of miR-1246 gene expression that targeted the DLG3 gene which contributes to neurological pathogenesis. In contrast, miR-30a that targets calcium channels for membrane transportation was down-regulated. This leads to repression of EV-A71 replication. The impact of host miRNAs on immune activation, shutdown of host protein synthesis, apoptosis, signal transduction and viral replication are discussed. miRNAs have been used in the construction of live attenuated vaccines (LAV) such as the poliovirus LAV that has miRNA binding sites for let-7a or miR-124a. The miRNAbearing vaccine will not replicate in neuronal cells carrying the corresponding miRNA but could still replicate in the gastrointestinal tract and hence remains to act as immunogens. As such, miRNAs are attractive candidates to be developed as vaccines and antivirals.
    Matched MeSH terms: Viral Vaccines/immunology
  14. Advances in diagnostics, vaccines and therapeutics for Nipah virus
    Thakur N, Bailey D
    Microbes Infect, 2019;21(7):278-286.
    PMID: 30817995 DOI: 10.1016/j.micinf.2019.02.002
    Nipah virus is an emerging zoonotic paramyxovirus that causes severe and often fatal respiratory and neurological disease in humans. The virus was first discovered after an outbreak of encephalitis in pig farmers in Malaysia and Singapore with subsequent outbreaks in Bangladesh or India occurring almost annually. Due to the highly pathogenic nature of NiV, its pandemic potential, and the lack of licensed vaccines or therapeutics, there is a requirement for research and development into highly sensitive and specific diagnostic tools as well as antivirals and vaccines to help prevent and control future outbreak situations.
    Matched MeSH terms: Viral Vaccines/immunology
  15. Anti-idiotype vaccine against cancer
    Bhattacharya-Chatterjee M, Chatterjee SK, Foon KA
    Immunol Lett, 2000 Sep 15;74(1):51-8.
    PMID: 10996628
    Immunization with anti-idiotype (Id) antibodies represents a novel new approach to active immunotherapy. Extensive studies in animal tumor models have demonstrated the efficacy of anti-Id vaccines in preventing tumor growth and curing mice with established tumor. We have developed and characterized several murine monoclonal anti-Id antibodies (Ab2) which mimic distinct human tumor-associated antigens (TAA) and can be used as surrogate antigens for triggering active anti-tumor immunity in cancer patients. Encouraging results have been obtained in recent clinical trials. In this article, we will review the existing literature and summarize our own findings showing the potential of this approach for various human cancers. We will also discuss where anti-Id vaccines may perform better than traditional antigen vaccines.
    Matched MeSH terms: Cancer Vaccines/immunology*
  16. Fulltext Isolated hepatitis B core antibody positive among vaccinated cohort in Malaysia
    Hudu SA, Malik YA, Niazlin MT, Harmal NS, Alshrari AS, Sekawi Z
    Ann Saudi Med, 2013;33(6):591-4.
    PMID: 24413864 DOI: 10.5144/0256-4947.2013.591
    BACKGROUND AND OBJECTIVES: Hepatitis B core antibodies (anti-HBc) are detected in almost every patient with previous exposure to hepatitis B virus (HBV). However, with this marker alone, one cannot understand the activity of the disease; therefore, this study aimed to identify the implication of isolated hepatitis B core antibody and evaluate the effect of hepatitis B vaccine booster in isolated anti-HBc among adults who received the HBV vaccine as infants.

    DESIGN AND SETTINGS: A prospective cohort study of vaccinated undergraduate students of University Putra Malaysia.

    PATIENTS AND METHODS: A total of 408 undergraduate students who received infant hepatitis B vaccination volunteered for this study; 5 mL of venous blood was taken from the volunteers. Hepatitis B surface antigen (HBsAg) and core antibodies were tested using a commercially available enzyme-linked immunosorbent assay kit according to the manufacturer's instructions (DRG international Inc., USA). Molecular detection of hepatitis B viral DNA was performed using nested polymerase chain reaction.

    RESULTS: The prevalence of isolated anti-HBc among the vaccinated cohort was found to be 5.0%, out of which 80% had a hepatitis B surface antibodies (anti-HBs) titer higher than 10 IU/L, while 20% had less than 10 IU/L anti-HBs titer. All the anti-HBc positivesubjects had detectable hepatitis B viral DNA in their serum. Anamnestic response was found to be 100% among isolated anti-HBc with negative antibody.

    CONCLUSION: Isolated anti-HBc developed protective levels of anti-HBs after a single dose of recombinant hepatitis B vaccination. HBV DNA was detected in all isolated anti-HBc indicating occult chronic HBV infection with undetectable HBsAg.

    Matched MeSH terms: Hepatitis B Vaccines/immunology
  17. Fulltext Burkholderia vaccines: are we moving forward?
    Choh LC, Ong GH, Vellasamy KM, Kalaiselvam K, Kang WT, Al-Maleki AR, et al.
    Front Cell Infect Microbiol, 2013;3:5.
    PMID: 23386999 DOI: 10.3389/fcimb.2013.00005
    The genus Burkholderia consists of diverse species which includes both "friends" and "foes." Some of the "friendly" Burkholderia spp. are extensively used in the biotechnological and agricultural industry for bioremediation and biocontrol. However, several members of the genus including B. pseudomallei, B. mallei, and B. cepacia, are known to cause fatal disease in both humans and animals. B. pseudomallei and B. mallei are the causative agents of melioidosis and glanders, respectively, while B. cepacia infection is lethal to cystic fibrosis (CF) patients. Due to the high rate of infectivity and intrinsic resistance to many commonly used antibiotics, together with high mortality rate, B. mallei and B. pseudomallei are considered to be potential biological warfare agents. Treatments of the infections caused by these bacteria are often unsuccessful with frequent relapse of the infection. Thus, we are at a crucial stage of the need for Burkholderia vaccines. Although the search for a prophylactic therapy candidate continues, to date development of vaccines has not advanced beyond research to human clinical trials. In this article, we review the current research on development of safe vaccines with high efficacy against B. pseudomallei, B. mallei, and B. cepacia. It can be concluded that further research will enable elucidation of the potential benefits and risks of Burkholderia vaccines.
    Matched MeSH terms: Bacterial Vaccines/immunology*
  18. Fulltext Progress and challenges toward the development of vaccines against avian infectious bronchitis
    Bande F, Arshad SS, Bejo MH, Moeini H, Omar AR
    J Immunol Res, 2015;2015:424860.
    PMID: 25954763 DOI: 10.1155/2015/424860
    Avian infectious bronchitis (IB) is a widely distributed poultry disease that has huge economic impact on poultry industry. The continuous emergence of new IBV genotypes and lack of cross protection among different IBV genotypes have been an important challenge. Although live attenuated IB vaccines remarkably induce potent immune response, the potential risk of reversion to virulence, neutralization by the maternal antibodies, and recombination and mutation events are important concern on their usage. On the other hand, inactivated vaccines induce a weaker immune response and may require multiple dosing and/or the use of adjuvants that probably have potential safety risks and increased economic burdens. Consequently, alternative IB vaccines are widely sought. Recent advances in recombinant DNA technology have resulted in experimental IB vaccines that show promise in antibody and T-cells responses, comparable to live attenuated vaccines. Recombinant DNA vaccines have also been enhanced to target multiple serotypes and their efficacy has been improved using delivery vectors, nanoadjuvants, and in ovo vaccination approaches. Although most recombinant IB DNA vaccines are yet to be licensed, it is expected that these types of vaccines may hold sway as future vaccines for inducing a cross protection against multiple IBV serotypes.
    Matched MeSH terms: Viral Vaccines/immunology*
  19. Fulltext Implications of a highly divergent dengue virus strain for cross-neutralization, protection, and vaccine immunity
    Chen RE, Smith BK, Errico JM, Gordon DN, Winkler ES, VanBlargan LA, et al.
    Cell Host Microbe, 2021 Nov 10;29(11):1634-1648.e5.
    PMID: 34610295 DOI: 10.1016/j.chom.2021.09.006
    Although divergent dengue viruses (DENVs) have been isolated in insects, nonhuman primates, and humans, their relationships to the four canonical serotypes (DENV 1-4) are poorly understood. One virus isolated from a dengue patient, DKE-121, falls between genotype and serotype levels of sequence divergence to DENV-4. To examine its antigenic relationship to DENV-4, we assessed serum neutralizing and protective activity. Whereas DENV-4-immune mouse sera neutralize DKE-121 infection, DKE-121-immune sera inhibit DENV-4 less efficiently. Passive transfer of DENV-4 or DKE-121-immune sera protects mice against homologous, but not heterologous, DENV-4 or DKE-121 challenge. Antigenic cartography suggests that DENV-4 and DKE-121 are related but antigenically distinct. However, DENV-4 vaccination confers protection against DKE-121 in nonhuman primates, and serum from humans immunized with a tetravalent vaccine neutralize DENV-4 and DKE-121 infection equivalently. As divergent DENV strains, such as DKE-121, may meet criteria for serotype distinction, monitoring their capacity to impact dengue disease and vaccine efficacy appears warranted.
    Matched MeSH terms: Dengue Vaccines/immunology*
  20. Cloning, expression, and purification of recombinant protein from a single synthetic multivalent construct of Mycobacterium tuberculosis
    Fang CM, Zainuddin ZF, Musa M, Thong KL
    Protein Expr Purif, 2006 Jun;47(2):341-7.
    PMID: 16510294 DOI: 10.1016/j.pep.2005.12.007
    Tuberculosis remains a major infectious disease with over 8 million new cases and 2 million deaths annually. Therefore, a vaccine more potent than BCG is desperately needed. In this regard, an approximately 800 bp DNA encoding a mycobacterial synthetic gene designated as VacIII (containing ubiquitin gene UbGR and four immunogenic mycobacterial epitopes or genes of ESAT-6, Phos1, Hsp 16.3, and Mtb8.4) was sub-cloned into a bacterial expression vector of pRSET-B resulting in a 6 x His-VacIII fusion gene construction. This recombinant clone was over expressed in Escherichia coli BL-21 (DE-3). The expressed fusion protein was found almost entirely in the insoluble form (inclusion bodies) in cell lysate. The inclusion bodies were solubilized with 8M urea and the recombinant protein was purified by Ni-NTA column and dialyzed by urea gradient dialysis. This method produced a relatively high yield of recombinant VacIII protein and the cloned VacIII gene offers the potential development of other vaccine formats such as DNA vaccine and recombinant vaccine.
    Matched MeSH terms: Tuberculosis Vaccines/immunology
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