Factors influencing the recommendation of the Human Papillomavirus vaccine by South African doctors working in a tertiary hospital.

Background: In South Africa, HPV vaccination programme has been incorporated recently in the school health system. Since doctors are the most trusted people regarding health issues in general, their knowledge and attitudes regarding HPV infections and vaccination are very important for HPV vaccine program nationally. Objective: The objective of this study was to investigate factors contributing to recommendation of HPV vaccines to the patients. Methods: This was a quantitative cross-sectional study conducted among 320 doctors, using a self-administered anonymous questionnaire. Results: All the doctors were aware of HPV and knew that HPV is transmitted sexually. Their overall level of knowledge regarding HPV infections and HPV vaccine was poor. But the majority intended to prescribe the vaccine to their patients. It was found that doctors who knew that HPV 6 and 11 are responsible for >90% of anogenital warts, their patients would comply with the counselling regarding HPV vaccination, and received sufficient information about HPV vaccination were 5.68, 4.91 and 4.46 times respectively more likely to recommend HPV vaccination to their patients, compared to their counterparts (p<0.05). Conclusion: There was a knowledge gap regarding HPV infection and HPV vaccine among the doctors.

Factors affecting vaccine handling and storage practices among immunization service providers in Ibadan, Oyo State, Nigeria.

Background: Improper handling has been identified as one of the major reasons for the decline in vaccine potency at the time of administration. Loss of potency becomes evident when immunised individuals contract the diseases the vaccines were meant to prevent. Objective: Assessing the factors associated with vaccine handling and storage practices. Methods: This was a cross-sectional study. Three-stage sampling was used to recruit 380 vaccine handlers from 273 health facilities from 11 Local Government areas in Ibadan. Data was analysed using SPSS version 16 Results: Seventy-three percent were aware of vaccine handling and storage guidelines with 68.4% having ever read such guidelines. Only 15.3% read a guideline less than 1 month prior to the study. About 65.0% had received training on vaccine management. Incorrect handling practices reported included storing injections with vaccines (13.7%) and maintaining vaccine temperature using ice blocks (7.6%). About 43.0% had good knowledge of vaccine management, while 66.1% had good vaccine management practices. Respondents who had good knowledge of vaccine handling and storage [OR=10.0, 95%CI (5.28 – 18.94), p < 0.001] and had received formal training on vaccine management [OR=5.3, 95%CI (2.50 – 11.14), p< 0.001] were more likely to have good vaccine handling and storage practices. Conclusion: Regular training is recommended to enhance vaccine handling and storage practices.

Co-administration of plasmid-encoded granulocyte-macrophage colony-stimulating factor increases human immunodeficiency virus-1 DNA vaccine-induced polyfunctional CD4+ T-cell responses

T-cell based vaccines against human immunodeficiency virus (HIV) generate specific responses that may limit both transmission and disease progression by controlling viral load. Broad, polyfunctional, and cytotoxic CD4+ T-cell responses have been associated with control of simian immunodeficiency virus/HIV-1 replication, supporting the inclusion of CD4+ T-cell epitopes in vaccine formulations. Plasmid-encoded granulocyte-macrophage colony-stimulating factor (pGM-CSF) co-administration has been shown to induce potent CD4+ T-cell responses and to promote accelerated priming and increased migration of antigen-specific CD4+ T-cells. However, no study has shown whether co-immunisation with pGM-CSF enhances the number of vaccine-induced polyfunctional CD4+ T-cells. Our group has previously developed a DNA vaccine encoding conserved, multiple human leukocyte antigen (HLA)-DR binding HIV-1 subtype B peptides, which elicited broad, polyfunctional and long-lived CD4+ T-cell responses. Here, we show that pGM-CSF co-immunisation improved both magnitude and quality of vaccine-induced T-cell responses, particularly by increasing proliferating CD4+ T-cells that produce simultaneously interferon-γ, tumour necrosis factor-α and interleukin-2. Thus, we believe that the use of pGM-CSF may be helpful for vaccine strategies focused on the activation of anti-HIV CD4+ T-cell immunity.

The mc2-CMX vaccine induces an enhanced immune response against Mycobacterium tuberculosis compared to Bacillus Calmette-Guérin but with similar lung inflammatory effects

Although the attenuated Mycobacterium bovis Bacillus Calmette-Guérin (BCG) vaccine has been used since 1921, tuberculosis (TB) control still proceeds at a slow pace. The main reason is the variable efficacy of BCG protection against TB among adults, which ranges from 0-80%. Subsequently, the mc2-CMX vaccine was developed with promising results. Nonetheless, this recombinant vaccine needs to be compared to the standard BCG vaccine. The objective of this study was to evaluate the immune response induced by mc2-CMX and compare it to the response generated by BCG. BALB/c mice were immunised with both vaccines and challenged with Mycobacterium tuberculosis (Mtb). The immune and inflammatory responses were evaluated by ELISA, flow cytometry, and histopathology. Mice vaccinated with mc2-CMX and challenged with Mtb induced an increase in the IgG1 and IgG2 levels against CMX as well as recalled specific CD4+ T-cells that produced T-helper 1 cytokines in the lungs and spleen compared with BCG vaccinated and challenged mice. Both vaccines reduced the lung inflammatory pathology induced by the Mtb infection. The mc2-CMX vaccine induces a humoral and cellular response that is superior to BCG and is efficiently recalled after challenge with Mtb, although both vaccines induced similar inflammatory reductions.

Original Research Article Humoral and cellular immune responses to modified hepatitis B plasmid DNA vaccine in mice

Purpose: To evaluate the immunogenicity and types of immune response of a quality-controlled modified recombinant hepatitis B surface antigen (HBsAg) plasmid encoding HBsAg in mice. Methods: The characterized plasmid DNA was used in the immunization of Balb/c mice. Three groups of mice were intramuscularly injected with three different concentrations (50, 25 and 10 μg/100 μL) of the modified plasmid. Humoral immune response was monitored by enzyme-linked immunosorbent assay (ELISA), while cellular immune response was investigated by analysis of spleen cytokine profile (TNFα, IFN γ and IL2) as well as CD69 expression level in CD4 and CD8 positive cells. Results: In general, the activated CD4 cells showing intracellular cytokines were higher than CD8 positive population of cells (p < 0.05). These findings indicate that the vaccine induced both a humoral and cellular immunity. Cytokine profile also showed high levels of TNFα, IFN γ and IL2 and CD69 expression in the group of animals immunized at a dose of 10 μg when compared to control group (p < 0.05). Conclusion: A 10 μg dose intramuscular injection of the modified DNA-based vaccine encoding HBsAg in mice induces both high humoral and cellular immune responses.

Protein expression of Myt272-3 recombinant clone and in silico prediction of a possible vaccine candidate against Mycobacterium tuberculosis

Purpose: To investigate the expression of Myt272-3 recombinant protein and also to predict a possible protein vaccine candidate against Mycobacterium tuberculosis . Methods: Myt272-3 protein was expressed in pET30a+-Myt272-3 clone. The purity of the protein was determined using Dynabeads® His-Tag Isolation & Pulldown. Protein sequence was analysed in silico using bioinformatics software for the prediction of allergenicity, antigenicity, MHC-I and MHC-II binding, and B-cell epitope binding. Results: The candidate protein was a non-allergen with 15.19 % positive predictive value. It was also predicted to be antigenic, with binding affinity to MHC-I and MHC-II, as well as B-cell epitope binding. Conclusion: The predicted results obtained in this study provide a guide for practical design of a new tuberculosis vaccine.