Displaying publications 1 - 20 of 22 in total

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  1. Aziz MHN, Safaruddin ADA, Hamzah NA, Supadi SS, Yuhao Z, Aziz MA
    Acta Biotheor, 2022 Nov 17;71(1):2.
    PMID: 36394646 DOI: 10.1007/s10441-022-09453-3
    A modified version of the SEIR model with the effects of vaccination and inter-state movement is proposed to simulate the spread of COVID-19 in Malaysia. A mathematical analysis of the proposed model was performed to derive the basic reproduction number. To enhance the model's forecasting capabilities, the model parameters were estimated using the Nelder-Mead simplex method by fitting the model outputs to the observed data. Our results showed a good fit between the model outputs and available data, where the model was then able to perform short-term predictions. In line with the rapid vaccination program, our model predicted that the COVID-19 cases in the country would decrease by the end of August. Furthermore, our findings indicated that relaxing travel restrictions from a highly vaccinated region to a low vaccinated region would result in an epidemic outbreak.
    Matched MeSH terms: Vaccination/methods
  2. Sah R, Khatiwada AP, Shrestha S, Bhuvan KC, Tiwari R, Mohapatra RK, et al.
    Travel Med Infect Dis, 2021;41:102037.
    PMID: 33781945 DOI: 10.1016/j.tmaid.2021.102037
    With the emergence of the new variants of concern (VOC) of the SARS-CoV-2, the efficacy of certain vaccines against them requires further research and considerations for future scenarios of COVID-19 vaccination. The vaccines' lack of efficacy against VOC will pose at risk to the vaccinated population and is a public health threat. In this commentary, we discuss Nepal's recent experiences and expectations regarding the confirmation of VOC B.1.1.7 from the United Kingdom in the country.
    Matched MeSH terms: Vaccination/methods*
  3. Xian TH, Sinniah K, Yean CY, Krishnamoorthy V, Bahari MB, Ravichandran M, et al.
    BMC Immunol, 2020 05 25;21(1):29.
    PMID: 32450807 DOI: 10.1186/s12865-020-00360-1
    BACKGROUND: Cholera, an acute watery diarrhoeal disease caused by Vibrio cholerae serogroup O1 and O139 across the continents. Replacing the existing WHO licensed killed multiple-dose oral cholera vaccines that demand 'cold chain supply' at 2-8 °C with a live, single-dose and cold chain-free vaccine would relieve the significant bottlenecks and cost determinants in cholera vaccination campaigns. In this direction, a prototype cold chain-free live attenuated cholera vaccine formulation (LACV) was developed against the toxigenic wild-type (WT) V. cholerae O139 serogroup. LACV was found stable and retained its viability (5 × 106 CFU/mL), purity and potency at room temperature (25 °C ± 2 °C, and 60% ± 5% relative humidity) for 140 days in contrast to all the existing WHO licensed cold-chain supply (2-8 °C) dependent killed oral cholera vaccines.

    RESULTS: The LACV was evaluated for its colonization potential, reactogenicity, immunogenicity and protective efficacy in animal models after its storage at room temperature for 140 days. In suckling mice colonization assay, the LACV recorded the highest recovery of (7.2 × 107 CFU/mL) compared to those of unformulated VCUSM14P (5.6 × 107 CFU/mL) and the WT O139 strain (3.5 × 107 CFU/mL). The LACV showed no reactogenicity even at an inoculation dose of 104-106 CFU/mL in a rabbit ileal loop model. The rabbits vaccinated with the LACV or unformulated VCUSM14P survived a challenge with WT O139 and showed no signs of diarrhoea or death in the reversible intestinal tie adult rabbit diarrhoea (RITARD) model. Vaccinated rabbits recorded a 275-fold increase in anti-CT IgG and a 15-fold increase in anti-CT IgA antibodies compared to those of rabbits vaccinated with unformulated VCUSM14P. Vibriocidal antibodies were increased by 31-fold with the LACV and 14-fold with unformulated VCUSM14P.

    CONCLUSION: The vaccine formulation mimics a natural infection, is non-reactogenic and highly immunogenic in vivo and protects animals from lethal wild-type V. cholerae O139 challenge. The single dose LACV formulation was found to be stable at room temperature (25 ± 2 °C) for 140 days and it would result in significant cost savings during mass cholera vaccination campaigns.

    Matched MeSH terms: Vaccination/methods
  4. Pang T, Gubler D, Goh DYT, Ismail Z, Asia Dengue Vaccine Advocacy Group
    Lancet, 2018 02 17;391(10121):654.
    PMID: 29617262 DOI: 10.1016/S0140-6736(18)30245-9
    Matched MeSH terms: Vaccination/methods
  5. Aini I, Ibrahim AL, Spradbrow PB
    Res Vet Sci, 1990 Sep;49(2):216-9.
    PMID: 2236920
    The food pellet vaccine has been shown to be effective in trials conducted under laboratory and simulated field conditions. The village chickens vaccinated with the food pellet vaccine during the field trial were protected against virulent Newcastle disease virus. The efficacy of the food pellet vaccine in the field was evaluated by challenge trial in which 60 per cent protection was obtained, or by monitoring the incidence of Newcastle disease in vaccinated and unvaccinated birds. There was no report of Newcastle disease outbreaks in the vaccinated birds during the two-year period of the field trial. The ease in administering the food pellet vaccine makes it readily accepted by the farmers.
    Matched MeSH terms: Vaccination/methods
  6. Mohd Hisham AA, Mat Yassim AS, Suppian R, Azlan M, Mohamad Asri AA, Idris NS, et al.
    Vaccine, 2024 Dec 02;42(26):126471.
    PMID: 39490114 DOI: 10.1016/j.vaccine.2024.126471
    This prospective cohort study examines the long-term humoral immune responses post-COVID-19 vaccination in 146 individuals who received either a homologous three-dose BNT162b2 vaccine regimen (PPP) or two primary doses of CoronaVac followed by BNT162b2 booster (SSP) in Malaysia. The study focuses on serum anti-S1-RBD-IgG, -IgA, and -IgM, using the ELISA method. The results show that BNT162b2 outperformed CoronaVac in the two dose primary vaccination series. BNT162b2 booster dose significantly raised serum anti-S1-RBD-IgG and -IgA levels, sustaining this increase from 26 to 52 weeks after administration, regardless of the vaccine regimen. This leads to equivalent levels of anti-S1-RBD-IgG and -IgA after boosting with BNT162b2 in both groups. Breakthrough infections, particularly with the emergence of the Omicron variant, did not result in increased anti-S1-RBD-IgG and -IgA levels. No significant induction of anti-S1-RBD-IgM was observed following multiple vaccine doses. The long-term investigation revealed that PPP and SSP groups had comparable humoral immune responses to SARS-CoV-2, highlighting the advantage of mRNA booster dose in our cohort.
    Matched MeSH terms: Vaccination/methods
  7. Rosli R, Nograles N, Hanafi A, Nor Shamsudin M, Abdullah S
    Hum Vaccin Immunother, 2013 Oct;9(10):2222-7.
    PMID: 24051430 DOI: 10.4161/hv.25325
    Polymeric carriers in the form of cellulose acetate phthalate (CAP) and alginate (ALG) microspheres were used for encapsulation of plasmid DNA for oral mucosal immunization. Access into the intestinal mucosa by pVAX1 eukaryotic expression plasmid vectors carrying gene-coding sequences, either for the cholera enterotoxin B subunit (ctxB) immunostimulatory antigen or the green fluorescent protein (GFP), delivered from both types of microsphere carriers were examined in orally immunized BALB/c mice. Demonstration of transgene protein expression and IgA antibody responses at local mucosal sites suggest immunological response to a potential oral DNA vaccine formulated within the microsphere carriers.
    Matched MeSH terms: Vaccination/methods*
  8. Kwang NB, Mahayudin T, Yien HL, Abdul Karim AK, Teik CK, Shan LP
    Asian Pac J Cancer Prev, 2016;17(1):267-74.
    PMID: 26838222
    BACKGROUND: Cervical cancer is the fourth most common cancer among women worldwide. Studies evaluating the effect of health education on knowledge and perception of cervical cancer have generated conflicting results. Thus, this study aimed to evaluate the effect of educational intervention towards knowledge of HPV vacccination for cervical cancer prevention among pre-university students in Malaysia.

    MATERIALS AND METHODS: This was an experimental before and after study performed between October 2014 and March 2015. Five hundred and eighty students were randomly assigned into intervention and control groups. All were required to complete both pre-intervention and post-intervention questionnaires. Those in the intervention group were given an information leaflet to read before answering the post-intervention questionnaire.

    RESULTS: Almost half (48.3%) of the students had poor knowledge, with a score less than 5, and only 51 (8.8%) exhibited good knowledge, with a score of 11 and above. After educational intervention, the number of students with poor knowledge was reduced to 177 (29.3%) and the number of students who exhibited good knowledge increased to 148 (25.5%). Students from the intervention group demonstrated significant higher total scores in knowledge regarding 'HPV infection and cervical cancer' (p=0.000) and 'HPV vaccination and cervical cancer prevention' (p=0.000) during post-intervention as compared to the control group.

    CONCLUSIONS: Knowledge on HPV infection and vaccination is low among pre-university students. Educational intervention in the form of information leaflets appears effective in creating awareness and improving knowledge.

    Matched MeSH terms: Vaccination/methods
  9. Laith AA, Abdullah MA, Nurhafizah WWI, Hussein HA, Aya J, Effendy AWM, et al.
    Fish Shellfish Immunol, 2019 Jul;90:235-243.
    PMID: 31009810 DOI: 10.1016/j.fsi.2019.04.052
    Streptococcus agalactiae species have been recognized as the main pathogen causing high mortality in fish leading to significant worldwide economical losses to the aquaculture industries. Vaccine development has become a priority in combating multidrug resistance in bacteria; however, there is a lack of commercial live attenuated vaccine (LAV) against S. agalactiae in Malaysia. The aim of this study is to compare two methods using attenuated bacteria as live vaccine and to evaluate the efficacy of selected LAV on the immune responses and resistance of Oreochromis niloticus (tilapia) against S. agalactiae. The LAV derived from S. agalactiae had been weakened using the chemical agent Acriflavine dye (LAV1), whereas the second vaccine was weakened using serial passages of bacteria on broth media (LAV2). Initial immunization was carried out only on day one, given twice-in the morning and evening, for the 42 day period. Serum samples were collected to determine the systemic antibody (IgM) responses and lysozymal (LSZ) activity using ELISA. On day 43 after immunization, the fish were injected intraperitoneally (i.p) with 0.1 mL of S. agalactiae at LD50 = 1.5 × 105 (CFU)/fish. Fish were monitored daily for 10 days. Clinical signs, mortality and the relative percent of survival (RPS) were recorded. Trial 1 results showed a significant increased (P 
    Matched MeSH terms: Vaccination/methods
  10. Shafie AA, Yeo HY, Coudeville L, Steinberg L, Gill BS, Jahis R, et al.
    Pharmacoeconomics, 2017 May;35(5):575-589.
    PMID: 28205150 DOI: 10.1007/s40273-017-0487-3
    BACKGROUND: Dengue disease poses a great economic burden in Malaysia.

    METHODS: This study evaluated the cost effectiveness and impact of dengue vaccination in Malaysia from both provider and societal perspectives using a dynamic transmission mathematical model. The model incorporated sensitivity analyses, Malaysia-specific data, evidence from recent phase III studies and pooled efficacy and long-term safety data to refine the estimates from previous published studies. Unit costs were valued in $US, year 2013 values.

    RESULTS: Six vaccination programmes employing a three-dose schedule were identified as the most likely programmes to be implemented. In all programmes, vaccination produced positive benefits expressed as reductions in dengue cases, dengue-related deaths, life-years lost, disability-adjusted life-years and dengue treatment costs. Instead of incremental cost-effectiveness ratios (ICERs), we evaluated the cost effectiveness of the programmes by calculating the threshold prices for a highly cost-effective strategy [ICER <1 × gross domestic product (GDP) per capita] and a cost-effective strategy (ICER between 1 and 3 × GDP per capita). We found that vaccination may be cost effective up to a price of $US32.39 for programme 6 (highly cost effective up to $US14.15) and up to a price of $US100.59 for programme 1 (highly cost effective up to $US47.96) from the provider perspective. The cost-effectiveness analysis is sensitive to under-reporting, vaccine protection duration and model time horizon.

    CONCLUSION: Routine vaccination for a population aged 13 years with a catch-up cohort aged 14-30 years in targeted hotspot areas appears to be the best-value strategy among those investigated. Dengue vaccination is a potentially good investment if the purchaser can negotiate a price at or below the cost-effective threshold price.

    Matched MeSH terms: Vaccination/methods
  11. Al-Naggar RA, Bobryshev YV
    Asian Pac J Cancer Prev, 2011;12(8):2045-9.
    PMID: 22292648
    OBJECTIVE: This study was performed to determine the practice of HPV vaccine among Malaysian women in the general population.
    METHODOLOGY: A cross-sectional study was conducted among 233 women during the Academic Year 2010/2011. Written consent was obtained from the participants and written information about the study was given enclosed with the questionnaire form, consisting of questions on socio-demographic characteristics, knowledge about HPV and practice of HPV vaccination. The protocol was approved by the ethics committee of Management and Science University (MSU). Data were analyzed using Statistical Package for Social Sciences (SPSS) version 13. The T-test and ANOVA test were used to explore the relation between socio-demographic characteristics and the practice of HPV vaccine.
    RESULTS: The majority of the participants were from the age group 17-30 years old, Malay, single and having tertiary education (67.8, 62.7, 62.2, 86.3%; respectively). As for knowledge, the majority of them heard about HPV (82.4%), knew that multiple sex partners increase the risk (71.7%). Regarding the practice of HPV vaccine among respondents, slightly more than half had been vaccinated (51.5%). Regarding the factors that influenced the practice of HPV vaccine among general population; age, marital status and family monthly income were significant (p=0.001, p=0.001, p=0.001; respectively).
    CONCLUSION: Age, marital status and income significantly influence the practice of HPV vaccine. Therefore promotion of HPV vaccine and inclusion in the national vaccination program is very important for primary prevention of cervical cancer among women.
    Matched MeSH terms: Vaccination/methods
  12. Aljunid S, Abuduxike G, Ahmed Z, Sulong S, Nur AM, Goh A
    BMC Infect Dis, 2011;11:248.
    PMID: 21936928 DOI: 10.1186/1471-2334-11-248
    BACKGROUND: Pneumococcal disease is the leading cause of vaccine-preventable death in children younger than 5 years of age worldwide. The World Health Organization recommends pneumococcal conjugate vaccine as a priority for inclusion into national childhood immunization programmes. Pneumococcal vaccine has yet to be included as part of the national vaccination programme in Malaysia although it has been available in the country since 2005. This study sought to estimate the disease burden of pneumococcal disease in Malaysia and to assess the cost effectiveness of routine infant vaccination with PCV7.
    METHODS: A decision model was adapted taking into consideration prevalence, disease burden, treatment costs and outcomes for pneumococcal disease severe enough to result in a hospital admission. Disease burden were estimated from the medical records of 6 hospitals. Where local data was unavailable, model inputs were obtained from international and regional studies and from focus group discussions. The model incorporated the effects of herd protection on the unvaccinated adult population.
    RESULTS: At current vaccine prices, PCV7 vaccination of 90% of a hypothetical 550,000 birth cohort would incur costs of RM 439.6 million (US$128 million). Over a 10 year time horizon, vaccination would reduce episodes of pneumococcal hospitalisation by 9,585 cases to 73,845 hospitalisations with cost savings of RM 37.5 million (US$10.9 million) to the health system with 11,422.5 life years saved at a cost effectiveness ratio of RM 35,196 (US$10,261) per life year gained.
    CONCLUSIONS: PCV7 vaccination of infants is expected to be cost-effective for Malaysia with an incremental cost per life year gained of RM 35,196 (US$10,261). This is well below the WHO's threshold for cost effectiveness of public health interventions in Malaysia of RM 71,761 (US$20,922).
    Matched MeSH terms: Vaccination/methods*
  13. Lum LC, Borja-Tabora CF, Breiman RF, Vesikari T, Sablan BP, Chay OM, et al.
    Vaccine, 2010 Feb 10;28(6):1566-74.
    PMID: 20003918 DOI: 10.1016/j.vaccine.2009.11.054
    Children aged 11 to <24 months received 2 intranasal doses of live attenuated influenza vaccine (LAIV) or placebo, 35+/-7 days apart. Dose 1 was administered concomitantly with a combined measles, mumps, and rubella vaccine (Priorix). Seroresponses to measles and mumps were similar between groups. Compared with placebo, response rates to rubella in LAIV+Priorix recipients were statistically lower at a 15 IU/mL threshold (83.9% vs 78.0%) and the prespecified noninferiority criteria were not met. In a post hoc analysis using an alternate widely accepted threshold of 10 IU/mL, the noninferiority criteria were met (93.4% vs 89.8%). Concomitant administration with Priorix did not affect the overall influenza protection rate of LAIV (78.4% and 63.8% against antigenically similar influenza strains and any strain, respectively).
    Matched MeSH terms: Vaccination/methods*
  14. Ochani RK, Batra S, Shaikh A, Asad A
    Infez Med, 2019 Jun 01;27(2):117-127.
    PMID: 31205033
    The Nipah virus was discovered twenty years ago, and there is considerable information available regarding the specificities surrounding this virus such as transmission, pathogenesis and genome. Belonging to the Henipavirus genus, this virus can cause fever, encephalitis and respiratory disorders. The first cases were reported in Malaysia and Singapore in 1998, when affected individuals presented with severe febrile encephalitis. Since then, much has been identified about this virus. These single-stranded RNA viruses gain entry into target cells via a process known as macropinocytosis. The viral genome is released into the cell cytoplasm via a cascade of processes that involves conformational changes in G and F proteins which allow for attachment of the viral membrane to the cell membrane. In addition to this, the natural reservoirs of this virus have been identified to be fruit bats from the genus Pteropus. Five of the 14 species of bats in Malaysia have been identified as carriers, and this virus affects horses, cats, dogs, pigs and humans. Various mechanisms of transmission have been proposed such as contamination of date palm saps by bat feces and saliva, nosocomial and human-to-human transmissions. Physical contact was identified as the strongest risk factor for developing an infection in the 2004 Faridpur outbreak. Geographically, the virus seems to favor the Indian sub-continent, Indonesia, Southeast Asia, Pakistan, southern China, northern Australia and the Philippines, as demonstrated by the multiple outbreaks in 2001, 2004, 2007, 2012 in Bangladesh, India and Pakistan as well as the initial outbreaks in Malaysia and Singapore. Multiple routes of the viremic spread in the human body have been identified such as the central nervous system (CNS) and respiratory system, while virus levels in the body remain low, detection in the cerebrospinal fluid is comparatively high. The virus follows an incubation period of 4 days to 2 weeks which is followed by the development of symptoms. The primary clinical signs include fever, headache, vomiting and dizziness, while the characteristic symptoms consist of segmental myoclonus, tachycardia, areflexia, hypotonia, abnormal pupillary reflexes and hypertension. The serum neutralization test (SNT) is the gold standard of diagnosis followed by ELISA if SNT cannot be carried out. On the other hand, treatment is supportive since there a lack of effective pharmacological therapy and only one equine vaccine is currently licensed for use. Prevention of outbreaks seems to be a more viable approach until specific therapeutic strategies are devised.
    Matched MeSH terms: Vaccination/methods
  15. Ninyio NN, Ho KL, Yong CY, Chee HY, Hamid M, Ong HK, et al.
    Int J Mol Sci, 2021 Feb 15;22(4).
    PMID: 33672018 DOI: 10.3390/ijms22041922
    Hepatitis B is a major global health challenge. In the absence of an effective treatment for the disease, hepatitis B vaccines provide protection against the viral infection. However, some individuals do not have positive immune responses after being vaccinated with the hepatitis B vaccines available in the market. Thus, it is important to develop a more protective vaccine. Previously, we showed that hepatitis B virus (HBV) 'a' determinant (aD) displayed on the prawn nodavirus capsid (Nc) and expressed in Spodoptera frugiperda (Sf9) cells (namely, Nc-aD-Sf9) self-assembled into virus-like particles (VLPs). Immunisation of BALB/c mice with the Nc-aD-Sf9 VLPs showed significant induction of humoral, cellular and memory B-cell immunity. In the present study, the biophysical properties of the Nc-aD-Sf9 VLPs were studied using dynamic light scattering (DLS) and circular dichroism (CD) spectroscopy. Enzyme-linked immunosorbent assay (ELISA) was used to determine the antigenicity of the Nc-aD-Sf9 VLPs, and multiplex ELISA was employed to quantify the cytokine response induced by the VLPs administered intramuscularly into BALB/c mice (n = 8). CD spectroscopy of Nc-aD-Sf9 VLPs showed that the secondary structure of the VLPs predominantly consisted of beta (β)-sheets (44.8%), and they were thermally stable up to ~52 °C. ELISA revealed that the aD epitope of the VLPs was significantly antigenic to anti-HBV surface antigen (HBsAg) antibodies. In addition, multiplex ELISA of serum samples from the vaccinated mice showed a significant induction (p < 0.001) of IFN-γ, IL-4, IL-5, IL-6, IL-10, and IL-12p70. This cytokine profile is indicative of natural killer cell, macrophage, dendritic cell and cytotoxic T-lymphocyte activities, which suggests a prophylactic innate and adaptive cellular immune response mediated by Nc-aD-Sf9 VLPs. Interestingly, Nc-aD-Sf9 induced a more robust release of the aforementioned cytokines than that of Nc-aD VLPs produced in Escherichia coli and a commercially used hepatitis B vaccine. Overall, Nc-aD-Sf9 VLPs are thermally stable and significantly antigenic, demonstrating their potential as an HBV vaccine candidate.
    Matched MeSH terms: Vaccination/methods*
  16. Cowling BJ, Caini S, Chotpitayasunondh T, Djauzi S, Gatchalian SR, Huang QS, et al.
    Vaccine, 2017 Feb 07;35(6):856-864.
    PMID: 28081970 DOI: 10.1016/j.vaccine.2016.12.064
    The fourth roundtable meeting of the Global Influenza Initiative (GII) was held in Hong Kong, China, in July 2015. An objective of this meeting was to gain a broader understanding of the epidemiology, surveillance, vaccination policies and programs, and obstacles to vaccination of influenza in the Asia-Pacific region through presentations of data from Australia, Hong Kong, India, Indonesia, Malaysia, New Zealand, the Philippines, Taiwan, Thailand, and Vietnam. As well as a need for improved levels of surveillance in some areas, a range of factors were identified that act as barriers to vaccination in some countries, including differences in climate and geography, logistical challenges, funding, lack of vaccine awareness and education, safety concerns, perceived lack of vaccine effectiveness, and lack of inclusion in national guidelines. From the presentations at the meeting, the GII discussed a number of recommendations for easing the burden of influenza and overcoming the current challenges in the Asia-Pacific region. These recommendations encompass the need to improve surveillance and availability of epidemiological data; the development and publication of national guidelines, where not currently available and/or that are in line with those proposed by the World Health Organization; the requirement for optimal timing of vaccination programs according to local or country-specific epidemiology; and calls for advocacy and government support of vaccination programs in order to improve availability and uptake and coverage. In conclusion, in addition to the varied epidemiology of seasonal influenza across this diverse region, there are a number of logistical and resourcing issues that present a challenge to the development of optimally effective vaccination strategies and that need to be overcome to improve access to and uptake of seasonal influenza vaccines. The GII has developed a number of recommendations to address these challenges and improve the control of influenza.
    Matched MeSH terms: Mass Vaccination/methods
  17. Mohd Yasin IS, Mohd Yusoff S, Mohd ZS, Abd Wahid Mohd E
    Trop Anim Health Prod, 2011 Jan;43(1):179-87.
    PMID: 20697957 DOI: 10.1007/s11250-010-9672-5
    This study was carried out to determine the antibody responses and protective capacity of an inactivated recombinant vaccine expressing the fimbrial protein of Pasteurella multocida B:2 following intranasal vaccination against hemorrhagic septicemia in goats. Goats were vaccinated intranasal with 10(6) CFU/mL of the recombinant vaccine (vaccinated group) and 10(6) CFU/mL of pET32/LIC vector without fimbrial protein (control group). All three groups were kept separated before all goats in the three groups were challenged with 10(9) CFU/mL of live pathogenic P. multocida B:2. During the course of study, both serum and lung lavage fluid were collected to evaluate the antibody levels via enzyme-linked immunosorbent assay. It was found that goats immunized with the inactivated recombinant vaccine developed a strong and significantly (p 
    Matched MeSH terms: Vaccination/methods
  18. Hasan NH, Ignjatovic J, Peaston A, Hemmatzadeh F
    Viral Immunol, 2016 05;29(4):198-211.
    PMID: 26900835 DOI: 10.1089/vim.2015.0127
    Vaccination is becoming a more acceptable option in the effort to eradicate avian influenza viruses (AIV) from commercial poultry, especially in countries where AIV is endemic. The main concern surrounding this option has been the inability of the conventional serological tests to differentiate antibodies produced due to vaccination from antibodies produced in response to virus infection. In attempts to address this issue, at least six strategies have been formulated, aiming to differentiate infected from vaccinated animals (DIVA), namely (i) sentinel birds, (ii) subunit vaccine, (iii) heterologous neuraminidase (NA), (iv) nonstructural 1 (NS1) protein, (v) matrix 2 ectodomain (M2e) protein, and (vi) haemagglutinin subunit 2 (HA2) glycoprotein. This short review briefly discusses the strengths and limitations of these DIVA strategies, together with the feasibility and practicality of the options as a part of the surveillance program directed toward the eventual eradication of AIV from poultry in countries where highly pathogenic avian influenza is endemic.
    Matched MeSH terms: Vaccination/methods
  19. Chen XY, Butt AM, Mohd Amin MCI
    Mol Pharm, 2019 09 03;16(9):3853-3872.
    PMID: 31398038 DOI: 10.1021/acs.molpharmaceut.9b00483
    The development of oral vaccine formulation is crucial to facilitate an effective mass immunization program for various vaccine-preventable diseases. In this work, the efficacy of hepatitis B antigen delivered by bacterial nanocellulose/poly(acrylic acid) composite hydrogel microparticles (MPs) as oral vaccine carriers was assessed to induce both local and systemic immunity. Optimal pH-responsive swelling, mucoadhesiveness, protein drug loading, and drug permeability were characterized by MPs formulated with minimal irradiation doses and acrylic acid concentration. The composite hydrogel materials of bacterial nanocellulose and poly(acrylic acid) showed significantly greater antigen release in simulated intestinal fluid while ensuring the integrity of antigen. In in vivo study, mice orally vaccinated with antigen-loaded hydrogel MPs showed enhanced vaccine immunogenicity with significantly higher secretion of mucosal immunoglobulin A, compared to intramuscular vaccinated control. The splenocytes from the same group demonstrated lymphoproliferation and significant increased secretion of interleukin-2 cytokines upon stimulation with hepatitis B antigen. Expression of CD69 in CD4+ T lymphocytes and CD19+ B lymphocytes in splenocytes from mice orally vaccinated with antigen-loaded hydrogel MPs was comparable to that of the intramuscular vaccinated control, indicating early activation of lymphocytes elicited by our oral vaccine formulation in just two doses. These results demonstrated the potential of antigen-loaded hydrogel MPs as an oral vaccination method for hepatitis B.
    Matched MeSH terms: Vaccination/methods*
  20. Seto WK, Lo YR, Pawlotsky JM, Yuen MF
    Lancet, 2018 11 24;392(10161):2313-2324.
    PMID: 30496122 DOI: 10.1016/S0140-6736(18)31865-8
    Chronic hepatitis B virus infection is a global public health threat that causes considerable liver-related morbidity and mortality. It is acquired at birth or later via person-to-person transmission. Vaccination effectively prevents infection and chronic hepatitis B virus carriage. In chronically infected patients, an elevated serum hepatitis B virus DNA concentration is the main risk factor for disease progression, although there are other clinical and viral parameters that influence disease outcomes. In addition to liver biochemistry, virological markers, and abdominal ultrasonography, non-invasive assessment of liver fibrosis is emerging as an important assessment modality. Long-term nucleos(t)ide-analogue therapy is safe and well tolerated, achieves potent viral suppression, and reduces the incidence of liver-related complications. However, a need to optimise management remains. Promising novel therapies are at the developmental stage. With current vaccines, therapies, and an emphasis on improving linkage to care, WHO's goal of eliminating hepatitis B virus as a global health threat by 2030 is achievable.
    Matched MeSH terms: Vaccination/methods
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