Interprofessional education in clinical practice: Not a single vaccine

In increasingly complex health service environments, the quality of teamwork and co-operation between doctors, nurses and allied health professionals, is 'under the microscope'. Interprofessional education (IPE), a process whereby health professionals learn 'from, with and about each other', is advocated as a response to widespread calls for improved communication and collaboration between healthcare professionals. Although there is much that is commendable in IPE, the authors caution that the benefits may be overstated if too much is attributed to, or expected of, IPE activities. The authors propose that clarity is required around what can realistically be achieved. Furthermore, engagement with clinicians in the clinical practice setting who are instrumental in assisting students make sense of their knowledge through practice, is imperative for sustainable outcomes. © AHHA 2010.

Non-segmented negative sense RNA viruses as vectors for vaccine development

This article intends to cover two aspects of non-segmented negative sense RNA viruses. In the initial section, the strategy employed by these viruses to replicate their genomes is discussed. This would help in understanding the later section in which the use of these viruses as vaccine vectors has been discussed. For the description of the replication strategy which encompasses virus genome transcription and genome replication carried out by the same RNA dependent RNA polymerase complex, a member of the prototype rhabdovirus family - Chandipura virus has been chosen as an example to illustrate the complex nature of the two processes and their regulation. In the discussion on these viruses serving as vectors for carrying vaccine antigen genes, emphasis has been laid on describing the progress made in using the attenuated viruses as vectors and a description of the systems in which the efficiency of immune responses has been tested.

A Safe Vaccine (DV-STM-07) against Salmonella Infection Prevents Abortion and Confers Protective Immunity to the Pregnant and New Born Mice

Pregnancy is a transient immuno-compromised condition which has evolved to avoid the immune rejection of the fetus by the maternal immune system. The altered immune response of the pregnant female leads to increased susceptibility to invading pathogens, resulting in abortion and congenital defects of the fetus and a subnormal response to vaccination. Active vaccination during pregnancy may lead to abortion induced by heightened cell mediated immune response. In this study, we have administered the highly attenuated vaccine strain delta pmrG-HM-D (DV-STM-07) in female mice before the onset of pregnancy and followed the immune reaction against challenge with virulent S. Typhimurium in pregnant mice. Here we demonstrate that DV-STM-07 vaccine gives protection against Salmonella in pregnant mice and also prevents Salmonella induced abortion. This protection is conferred by directing the immune response towards Th2 activation and Th1 suppression. The low Th1 response prevents abortion. The use of live attenuated vaccine just before pregnancy carries the risk of transmission to the fetus. We have shown that this vaccine is safe as the vaccine strain is quickly eliminated from the mother and is not transmitted to the fetus. This vaccine also confers immunity to the new born mice of vaccinated mothers. Since there is no evidence of the vaccine candidate reaching the new born mice, we hypothesize that it may be due to trans-colostral transfer of protective anti-Salmonella antibodies. These results suggest that our vaccine DV-STM-07 can be very useful in preventing abortion in the pregnant individuals and confer immunity to the new born. Since there are no such vaccine candidates which can be given to the new born and to the pregnant women, this vaccine holds a very bright future to combat Salmonella induced pregnancy loss.

Mother-Infant Antibodies to Pneumococcal Polysaccharides and Proteins : Transfer and Persistence of Maternal Antibodies and Development of Vaccine-Induced and Naturally Acquired Antibodies in Infants

Symptomless nasopharyngeal carriage of Streptococcus pneumoniae (pneumococcus) is very common in young children. Occasionally the carriage proceeds into mild mucosal diseases, such as sinusitis or acute otitis media, or into serious life-threatening diseases, such as pneumonia, sepsis or meningitis. Each year, up to one million children less than five years of age worldwide die of invasive pneumococcal diseases (IPD). Especially in the low-income countries IPD is a leading health problem in infants; 75% of all IPD cases occur before one year of age. This stresses the need of increased protection against pneumococcus in infancy. Anti-pneumococcal antibodies form an important component in the defence against pneumococcal infection. Maternal immunisation and early infant immunisation are two possible ways by which potentially protective antibody concentrations against pneumococci could be achieved in early infancy. The aim of this thesis is to increase the knowledge of antibody mediated protection against pneumococcal disease in infants and young children. We investigated the transfer of maternal anti-pneumococcal antibodies from Filipino mothers to their infants, the persistence of the transferred antibodies in the infants, the immunogenicity of the 23-valent pneumococcal polysaccharide vaccine (PPV) in infants and the response of the children to a second dose of PPV at three years of age. We also investigated the development of antibodies to pneumococcal protein antigens in relation to culture-confirmed pneumococcal carriage in infants. Serum samples were collected from the mothers, the umbilical cords and from the infants at young age as well as at three years of age. The samples were used to determine the antibody concentrations to pneumococcal serotypes 1, 5, 6B, 14, 18C and 19F, as well as to the pneumococcal proteins PspA, PsaA, Ply, PspC, PhtD, PhtDC and LytC by the enzyme immunoassay. The findings of the present study confirm previously obtained results and add to the global knowledge of responses to PPV in young children. Immunising pregnant women with PPV provides the infants with increased concentrations of pneumococcal polysaccharide antibodies. Of the six serotypes examined, serotypes 1 and 5 were immunogenic already in infants. At three years of age, the children responded well to the second dose of PPV suggesting that maternal and early infant immunisations might not induce hyporesponsiveness to polysaccharide antigens after subsequent immunisations. The anti-protein antibody findings provide useful information for the development of pneumococcal protein vaccines. All six proteins studied were immunogenic in infancy and the development of anti-protein antibodies started early in life in relation to pneumococcal carriage.

Recombinant mid gut antigen (Bm95) as a vaccine against Indian Rhiphicephalus haemaphysaloides in Bos indicus cattle

In the present study, we report for the first time the efficacy of recombinant Bm95 mid gut antigen isolated from an Argentinean strain of Rhipicephalus microplus strain A in controlling the tick infestations in India. The synthetic gene for Bm95 optimized for expression in yeast was obtained and used to generate yeast transformants expressing Bm95 which was purified to apparent homogeneity. Liquid chromatography-mass spectrometry analysis of the purified protein confirmed its identity as Bm95. Vaccine was prepared by blending various concentrations of purified Bm95 with aluminium hydroxide as an adjuvant. lmmunogenicity studies of the vaccine in rabbits and cattle indicated that the vaccine was highly immunogenic. The efficacy studies of the vaccine was done in cattle. Naive Bos indicus cattle were vaccinated with the recombinant vaccine and were challenged with the larval, nymphal and adult forms of Rhiphicephalus haemaphysaloides. The vaccine protected the animals from larval, nymph and adult tick challenges with an efficacy of 98.7%, 84.6% and 78.9% respectively. The results obtained from the above studies clearly demonstrated the advantage and possibilities of the use of Bm95 in controlling R. haemaphysaloides infestations in the field. (C) 2010 Elsevier Ltd. All rights reserved.

Needleless Vaccine Delivery Using Micro-Shock Waves

Shock waves are one of the most efficient mechanisms of energy dissipation observed in nature. In this study, utilizing the instantaneous mechanical impulse generated behind a micro-shock wave during a controlled explosion, a novel nonintrusive needleless vaccine delivery system has been developed. It is well-known that antigens in the epidermis are efficiently presented by resident Langerhans cells, eliciting the requisite immune response, making them a good target for vaccine delivery. Unfortunately, needle-free devices for epidermal delivery have inherent problems from the perspective of the safety and comfort of the patient. The penetration depth of less than 100 mu m in the skin can elicit higher immune response without any pain. Here we show the efficient utilization of our needleless device (that uses micro-shock waves) for vaccination. The production of liquid jet was confirmed by high-speed microscopy, and the penetration in acrylamide gel and mouse skin was observed by confocal microscopy. Salmonella enterica serovar Typhimurium vaccine strain pmrG-HM-D (DV-STM-07) was delivered using our device in the murine salmonellosis model, and the effectiveness of the delivery system for vaccination was compared with other routes of vaccination. Vaccination using our device elicits better protection and an IgG response even at a lower vaccine dose (10-fold less) compared to other routes of vaccination. We anticipate that our novel method can be utilized for effective, cheap, and safe vaccination in the near future.

Responsiveness of human male volunteers to immunization with ovine follicle stimulating hormone vaccine: Results of a pilot study

A study of 140 days duration was performed to examine if human male volunteers (n = 5) respond to ovine follicle stimulating hormone (oFSH) immunization (administered adsorbed on Alugel on days 1, 20, 40 and 70) by producing antibodies capable of both binding and neutralizing bioactivity of human FSH. The kinetics of antibody production for both the immunogen (oFSH) and the cross-reactive antigen (hFSH) were essentially similar, The volunteers responded only to the first two immunizations, The boosters given on days 40 and 70 were ineffective, probably because of the presence of substantial amounts of circulating antibody to oFSH. Of the antibodies generated to oFSH, 25-45% bound hFSH with a mean binding affinity of 0.65 x 10(9) +/- 0.53 M(-1). The binding capacities at the time of high (30-80 days of immunization) and low (>110 days) titres were 346 +/- 185 and 10.5 +/- 5.8 ng hFSH/ml respectively, During the period of high titre, free serum FSH (value in normal males 1-5 ng/ml) was not monitorable, A 50 mu l aliquot of the antiserum obtained from different volunteers between days 30 and 80 and on day 140 blocked binding of I-125-labelled hFSH to its receptor by 82 +/- 9.7 and 53 +/- 12.2% respectively, The antibody produced was specific for FSH, and no significant change in the values of related glycoprotein hormones (luteinizing hormone/testosterone and thyroid stimulating hormone/thyroxine) were recorded, Seminal plasma transferrin, a marker of Sertoli cell as well as of seminiferous tubular function, showed marked reduction (30-90%) following immunization with oFSH. Considering that endogenous FSH remained neutralized for approximately one sperm cycle only (65 days), the reduction in sperm counts (30-74%) exhibited by some volunteers is encouraging, Immunization with oFSH did not result in any significant changes in haematology, serum biochemistry or hormonal profiles, There was no production of antibodies capable of interacting with non-specific tissues, It is concluded that it should be possible to obtain a sustained long-term blockade of endogenous FSH action in men by using oFSH as an immunogen, This is a prerequisite for obtaining significant reduction in the quality and quantity of spermatozoa produced, thus leading to infertility.

Typhoid fever & vaccine development: a partially answered question

Typhoid fever is a systemic disease caused by the human specific Gram-negative pathogen Salmonella enterica serovar Typhi (S Typhi). The extra-intestinal infections caused by Salmonella are very fatal. The incidence of typhoid fever remains very high in impoverished areas and the emergence of multidrug resistance has made the situation worse. To combat and to reduce the morbidity and mortality caused by typhoid fever, many preventive measures and strategies have been employed, the most important being vaccination. In recent years, many Salmonella vaccines have been developed including live attenuated as well as DNA vaccines and their clinical trials have shown encouraging results. But with the increasing antibiotic resistance, the development of potent vaccine candidate for typhoid fever is a need of the hour. This review discusses the latest trends in the typhoid vaccine development and the clinical trials which are underway.

Pre-clinical toxicity & immunobiological evaluation of DNA rabies vaccine & combination rabies vaccine in rhesus monkeys (Macaca mulatta)

Background & objectives: Pre-clinical toxicology evaluation of biotechnology products is a challenge to the toxicologist. The present investigation is an attempt to evaluate the safety profile of the first indigenously developed recombinant DNA anti-rabies vaccine DRV (100 mu g)] and combination rabies vaccine CRV (100 mu g DRV and 1.25 IU of cell culture-derived inactivated rabies virus vaccine)], which are intended for clinical use by intramuscular route in Rhesus monkeys. Methods: As per the regulatory requirements, the study was designed for acute (single dose - 14 days), sub-chronic (repeat dose - 28 days) and chronic (intended clinical dose - 120 days) toxicity tests using three dose levels, viz. therapeutic, average (2x therapeutic dose) and highest dose (10 x therapeutic dose) exposure in monkeys. The selection of the model i.e. monkey was based on affinity and rapid higher antibody response during the efficacy studies. An attempt was made to evaluate all parameters which included physical, physiological, clinical, haematological and histopathological profiles of all target organs, as well as Tiers I, II, III immunotoxicity parameters. Results: In acute toxicity there was no mortality in spite of exposing the monkeys to 10XDRV. In sub chronic and chronic toxicity studies there were no abnormalities in physical, physiological, neurological, clinical parameters, after administration of test compound in intended and 10 times of clinical dosage schedule of DRV and CRV under the experimental conditions. Clinical chemistry, haematology, organ weights and histopathology studies were essentially unremarkable except the presence of residual DNA in femtogram level at site of injection in animal which received 10X DRV in chronic toxicity study. No Observational Adverse Effects Level (NOAEL) of DRV is 1000 ug/dose (10 times of therapeutic dose) if administered on 0, 4, 7, 14, 28th day. Interpretation & conclusions: The information generated by this study not only draws attention to the need for national and international regulatory agencies in formulating guidelines for pre-clinical safety evaluation of biotech products but also facilitates the development of biopharmaceuticals as safe potential therapeutic agents.

Progress in tuberculosis vaccine development and host-directed therapies-a state of the art review

Tuberculosis continues to kill 1.4 million people annually. During the past 5 years, an alarming increase in the number of patients with multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis has been noted, particularly in eastern Europe, Asia, and southern Africa. Treatment outcomes with available treatment regimens for drug-resistant tuberculosis are poor. Although substantial progress in drug development for tuberculosis has been made, scientific progress towards development of interventions for prevention and improvement of drug treatment outcomes have lagged behind. Innovative interventions are therefore needed to combat the growing pandemic of multidrug-resistant and extensively drug-resistant tuberculosis. Novel adjunct treatments are needed to accomplish improved cure rates for multidrug-resistant and extensively drug-resistant tuberculosis. A novel, safe, widely applicable, and more effective vaccine against tuberculosis is also desperately sought to achieve disease control. The quest to develop a universally protective vaccine for tuberculosis continues. So far, research and development of tuberculosis vaccines has resulted in almost 20 candidates at different stages of the clinical trial pipeline. Host-directed therapies are now being developed to refocus the anti-Mycobacterium tuberculosis-directed immune responses towards the host; a strategy that could be especially beneficial for patients with multidrug-resistant tuberculosis or extensively drug-resistant tuberculosis. As we are running short of canonical tuberculosis drugs, more attention should be given to host-directed preventive and therapeutic intervention measures.

A Multiantigenic DNA Vaccine That Induces Broad Hepatitis C Virus-Specific T-Cell Responses in Mice

There are 3 to 4 million new hepatitis C virus (HCV) infections annually around the world, but no vaccine is available. Robust T-cell mediated responses are necessary for effective clearance of the virus, and DNA vaccines result in a cell-mediated bias. Adjuvants are often required for effective vaccination, but during natural lytic viral infections damage-associated molecular patterns (DAMPs) are released, which act as natural adjuvants. Hence, a vaccine that induces cell necrosis and releases DAMPs will result in cell-mediated immunity (CMI), similar to that resulting from natural lytic viral infection. We have generated a DNA vaccine with the ability to elicit strong CMI against the HCV nonstructural (NS) proteins (3, 4A, 4B, and 5B) by encoding a cytolytic protein, perforin (PRF), and the antigens on a single plasmid. We examined the efficacy of the vaccines in C57BL/6 mice, as determined by gamma interferon enzyme-linked immunosorbent spot assay, cell proliferation studies, and intracellular cytokine production. Initially, we showed that encoding the NS4A protein in a vaccine which encoded only NS3 reduced the immunogenicity of NS3, whereas including PRF increased NS3 immunogenicity. In contrast, the inclusion of NS4A increased the immunogenicity of the NS3, NS4B, andNS5B proteins, when encoded in a DNA vaccine that also encoded PRF. Finally, vaccines that also encoded PRF elicited similar levels of CMI against each protein after vaccination with DNA encoding NS3, NS4A, NS4B, and NS5B compared to mice vaccinated with DNA encoding only NS3 or NS4B/5B. Thus, we have developed a promising ``multiantigen'' vaccine that elicits robust CMI. IMPORTANCE Since their development, vaccines have reduced the global burden of disease. One strategy for vaccine development is to use commercially viable DNA technology, which has the potential to generate robust immune responses. Hepatitis C virus causes chronic liver infection and is a leading cause of liver cancer. To date, no vaccine is currently available, and treatment is costly and often results in side effects, limiting the number of patients who are treated. Despite recent advances in treatment, prevention remains the key to efficient control and elimination of this virus. Here, we describe a novel DNA vaccine against hepatitis C virus that is capable of inducing robust cell-mediated immune responses in mice and is a promising vaccine candidate for humans.

Haloarchaeal gas vesicle nanoparticles displaying Salmonella antigens as a novel approach to vaccine development

A safe, effective, and inexpensive vaccine against typhoid and other Salmonella diseases is urgently needed. In order to address this need, we are developing a novel vaccine platform employing buoyant, self-adjuvanting gas vesicle nanoparticles (GVNPs) from the halophilic archaeon Halobacterium sp. NRC-1, bioengineered to display highly conserved Salmonella enterica antigens. As the initial antigen for testing, we selected SopB, a secreted inosine phosphate effector protein injected by pathogenic S. enterica bacteria during infection into the host cells. Two highly conserved sopB gene segments near the 3'- region, named sopB4 and sopB5, were each fused to the grIpC gene, and resulting SopB-GVNPs were purified by centrifugally accelerated flotation. Display of SopB4 and SopB5 antigenic epitopes on GVNPs was established by Western blotting analysis using antisera raised against short synthetic peptides of SopB. Immunostimulatory activities of the SopB4 and B5 nanoparticles were tested by intraperitoneal administration of SopB-GVNPs to BALB/c mice which had been immunized with S. enterica serovar Typhimurium 14028 ApmrG-H111-D (DV-STM-07), a live attenuated vaccine strain. Proinflammatory cytokines IFN-y, IL-2, and IL-9 were significantly induced in mice boosted with SopB5-GVNPs, consistent with a robust Thl response. After challenge with virulent S. enterica serovar Typhimurium 14028, bacterial burden was found to be diminished in spleen of mice boosted with SopB4-GVNPs and absent or significantly diminished in liver, mesenteric lymph node, and spleen of mice boosted with SopB5GVNPs, indicating that the C-terminal portions of SopB displayed on GVNPs elicit a protective response to Salmonella infection in mice. SopB antigen-GVNPs were also found to be stable at elevated temperatures for extended periods without refrigeration. The results show that bioengineered GVNPs are likely to represent a valuable platform for antigen delivery and development of improved vaccines against Salmonella and other diseases.