Detection of unusual mutation within the VP1 region of different re-isolates of poliovirus Sabin vaccine

In the present study, a genomic analysis of full VP1 sequence region of 15 clinical re-isolates (14 healthy vaccinees and one bone marrow tumor patient) was conducted, aiming to the identification of mutations and to the assessment of their impact on virus fitness, providing also insights relevant with the natural evolution of Sabin strains. Clinical re-isolates were analyzed by RT-PCR, sequencing and computational analysis. Some re-isolates were characterized by an unusual mutational pattern in which non-synonymous mutations outnumbered the synonymous ones. Furthermore, the majority of amino-acid substitutions were located in the capsid exterior, specifically in N-Ags, near N-Ags and in the north rim of the canyon. Also mutations, which are well-known determinants of attenuation, were identified. The results of this study propose that some re-isolates are characterized by an evolutionary pattern in which non-synonymous mutations with a direct phenotypic impact on viral fitness are fixed in viral genomes, in spite of synonymous ones with no phenotypic impact on viral fitness. Results of the present retrospective characterization of Sabin clinical re-isolates, based on the full VP1 sequence, suggest that vaccine-derived viruses may make their way through narrow breaches and may evolve into transmissible pathogens even in adequately immunized populations. For this reason increased poliovirus laboratory surveillance should be permanent and full VP1 sequence analysis should be conducted even in isolates originating from healthy vaccinees.

Attenuating mutations in the influenza virus genome which may increase the safety of vaccine production

Influenza virus epidemics occur on an annual basis and cause severe disease in the very young and old. The vaccine administered to high-risk groups is generated by amplifying reassortant viruses, with chronologically relevant viral surface antigens, in eggs. Every 20 years or so, influenza pandemics occur causing widespread fatality in all age groups. These viruses display novel viral surface antigens acquired from a zoonotic source, and vaccination against them poses new issues since production of large amounts of a respiratory virus containing novel surface antigens could be dangerous for those involved in manufacture. To minimise risks, it is advisable to use a virus whose genetic backbone is highly attenuated in man. Traditionally, the A/PR/8/34 strain of virus is used, however, the genetic basis of its attenuation is unclear. Cold-adapted (CA) strains of the influenza virus are all based on the H2N2 subtype, itself a virus with pandemic potential, and again the genetic basis of temperature sensitivity is not yet established. Reverse genetics technology allows us to engineer designer influenza viruses to order. Using this technology, we have been investigating mutations in several different gene segments to effectively attenuate potential vaccine strains allowing the safe production of vaccine to protect against the next pandemic. (C) 2003 Elsevier B.V. All rights reserved.

Can a short period of micronutrient supplementation in older institutionalized people improve response to influenza vaccine? A randomized, controlled trial

OBJECTIVES: To test the hypothesis that a micronutrient supplement can improve seroconversion after influenza immunization in older institutionalized people. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Nursing and residential homes in Liverpool, United Kingdom. PARTICIPANTS: One hundred sixty-four residents aged 60 and older from 31 homes were initially randomized; of these, 119 (72.6%) completed the study. INTERVENTION: Participants were randomized to receive a micronutrient supplement providing the reference nutrient intake for all vitamins and trace elements or identical placebo. Tablets were taken over an 8-week period during September and October 2000; influenza vaccine was administered 4 weeks after their commencement. MEASUREMENTS: The hemagglutination-inhibiting antibody response as defined by a fourfold or greater titer rise over 4 weeks and assessed separately for each of the three antigens contained in the 2000/2001 influenza vaccine (A/New Caledonia/20/99 (H1N1), A/Moscow/10/99 (H3N2), B/Beijing/184/93 (B)). RESULTS: Despite a significant increase in serum concentrations of vitamins A, C, D-3, E, folate, and selenium in the supplemented group, there was no significant difference between groups (supplemented vs placebo, respectively) in the proportion of participants seroconverting to H1N1 (41% vs 49%, P=.374), H3N2 (49% vs 58%, P=.343), or B (41% vs 40%, P=.944). CONCLUSION: A micronutrient supplement providing the reference nutrient intake administered over 8 weeks had no beneficial effect on antibody response to influenza vaccine in older people living in long-term care.

Farmers’ willingness to pay for a tuberculosis cattle vaccine

We use contingent valuation (CV) and choice experiment (CE) methods to assess cattle farmers’ attitudes to and willingness to pay (WTP) for a bovine tuberculosis (bTB) cattle vaccine, to help inform vaccine development and policy. A survey questionnaire was administered by means of telephone interviews to a stratified sample of 300 cattle farmers in annually bTB-tested areas in England and Wales. Farmers felt that bTB was a major risk for the cattle industry and that there was a high risk of their cattle getting the disease. The CE estimate produced a mean WTP of £35 per animal per single dose for a vaccine that is 90% effective at reducing the risk of a bTB breakdown and an estimated £55 for such a vaccine backed by 100% insurance of loss if a breakdown should occur. The CV estimate produced a mean WTP of nearly £17 per dose/per animal/per year for a vaccine (including 100% insurance) which, given the average lifespan of cattle, is comparable to the CE estimate. These WTP estimates are substantially higher than the expected cost of a vaccine which suggests that farmers in high risk bTB ‘hotspot’ areas perceive a substantial net benefit from buying the vaccine.

Modulation of vaccine response by concomitant probiotic administration

Evidence suggests that probiotic bacteria modulate both innate and adaptive immunity in the host, and in some situations can result in reduced severity of common illnesses, such as acute rotavirus infection and respiratory infections. Responses to vaccination are increasingly being used to provide high quality information on the immunomodulatory effects of dietary components in humans. The present review focuses on the effect of probiotic administration upon vaccination response. The majority of studies investigating the impact of probiotics on responses to vaccination have been conducted in healthy adults, and at best they show modest effects of probiotics on serum or salivary IgA titres. Studies in infants and in elderly subjects are very limited, and it is too early to draw any firm conclusions regarding the potential for probiotics to act as adjuvants in vaccination. Although some studies are comparable in terms of duration of the intervention and age and characteristics of the subjects, most differ in terms of the probiotic selected. Further well designed, randomized, placebo-controlled studies are needed to fully understand the immunomodulatory properties of probiotics, whether the effects exerted are strain-dependent and age-dependent, and their clinical relevance in enhancing immune protection following vaccination.

A laboratory study of an inactivated bivalent iron restricted Salmonella enterica serovars Enteritidis and Typhimurium dual vaccine against Typhimurium challenge in chickens

A commercial inactivated iron restricted Salmonella Typhimurium and Salmonella Enterifidis vaccine was used to vaccinate chicks at I day and again at 4 weeks of age, with challenge by a high and a low dose of S. Typhimurium given either orally or by contact with seeder birds inoculated orally with a high dose of S. Typhimurium. In all three challenge regimes, the shedding of challenge strain was reduced significantly (p < 0.05) in vaccinated birds compared with unvaccinated controls. Vaccination reduced colonisation of internal organs after challenge by contact seeder birds. However, no effect of vaccination upon colonisation of internal organs after either high or low oral challenge was apparent. In conclusion, the data indicate that the vaccine should be a useful tool in the control of S. Typhimurium infection in chickens. (C) 2002 Elsevier Science B.V. All rights reserved.

The efficacy of Salenvac, a Salmonella enterica subsp. Enterica serotype Enteritidis iron-restricted bacterin vaccine, in laying chickens

The protective effect of two vaccination regimes using Salenvac, a commercially available iron-restricted Salmonella enterica subsp. Enterica serotype Enteritidis PT4 bacterin vaccine, was verified in laying birds. Immunization was intramuscular at 1 day old and again at 4 weeks of age (V2), or at 1 day and 4 weeks with a third dose at 18 weeks of age (V3). Challenge S. Enteritidis (5 to 7.5) x 10(7) colony forming units) was given intravenously at 8, 17, 23, 30 and 59 weeks of age. For all age groups, both vaccination regimes reduced significantly the number of tissues and faecal samples that were culture positive for the challenge strain. For laying birds, fewer eggs (P < 0.001) were culture positive for S. Enteritidis after challenge from vaccinated laying birds ( 56/439 batches of eggs) than unvaccinated birds (99/252 batches). The data give compelling evidence that the vaccine is efficacious and may contribute to the reduction of layer infection and egg contamination.

What have dendritic cells ever done for adjuvant design? Cellular and molecular methods for the rational development of vaccine adjuvants

Our new molecular understanding of immune priming states that dendritic cell activation is absolutely pivotal for expansion and differentiation of naïve T lymphocytes, and it follows that understanding DC activation is essential to understand and design vaccine adjuvants. This chapter describes how dendritic cells can be used as a core tool to provide detailed quantitative and predictive immunomics information about how adjuvants function. The role of distinct antigen, costimulation, and differentiation signals from activated DC in priming is explained. Four categories of input signals which control DC activation – direct pathogen detection, sensing of injury or cell death, indirect activation via endogenous proinflammatory mediators, and feedback from activated T cells – are compared and contrasted. Practical methods for studying adjuvants using DC are summarised and the importance of DC subset choice, simulating T cell feedback, and use of knockout cells is highlighted. Finally, five case studies are examined that illustrate the benefit of DC activation analysis for understanding vaccine adjuvant function.

The Prophetic Sound: a day and night of noise cabaret(symposium of talks and live performances)

'The Prophetic Sound: a day and night of noise cabaret' is the first event hosted by Agency of Noise. This all day event brought together artists and academics whose subject of focus is noise (in creative practice). Artists from across the UK were invited to consider a future post-digital era in which everything with a microchip has malfunctioned, as a thought exercise and starting point for response through sound. In response to Jacques Attali’s claim that music is prophecy, The Prophetic Sound asks us to consider if noise can communicate in an unbridled, unfiltered, way that is somehow not culturally coded -before it becomes sound that is recognised, refined, manipulated and exploited for musical or other cultured purpose. Featuring students from Reading, Brighton, LCC and Goldsmiths alongside more established artists and academics from across the UK, this event brings into focus locations where pattern, timbre, pitch, organisation and sequencing of sounds become distinguishable from noise and asks us to consider, through diversion within such locations, new origins for future communication systems. The Prophetic Sound included talks, films, presentations and performances from: Ryo Ikeshiro / Inigo Wilkins / Neal Spowage / Dane Sutherland / Poulomi Desai / Benedict Drew / AAS / Polly Fibre / Steven Dickie As part of The Prophetic Sound, POLLYFIBRE (Ellison, C.) performed LIVE RECORDING with Amplified Scissors. This industrial activity by POLLYFIBRE short-circuits the complicated chain that is music production. The distinctive roles of consumer, producer, composer, and performer collapse in a series of live ‘cuts’ where vinyl discs are produced with amplified scissors. Production happens through action and action becomes production. A limited edition of 9 flexi discs were produced and available for special collectors at the event.

Rational engineering of recombinant picornavirus capsids to produce safe, protective vaccine antigen

Foot-and-mouth disease remains a major plague of livestock and outbreaks are often economically catastrophic. Current inactivated virus vaccines require expensive high containment facilities for their production and maintenance of a cold-chain for their activity. We have addressed both of these major drawbacks. Firstly we have developed methods to efficiently express recombinant empty capsids. Expression constructs aimed at lowering the levels and activity of the viral protease required for the cleavage of the capsid protein precursor were used; this enabled the synthesis of empty A-serotype capsids in eukaryotic cells at levels potentially attractive to industry using both vaccinia virus and baculovirus driven expression. Secondly we have enhanced capsid stability by incorporating a rationally designed mutation, and shown by X-ray crystallography that stabilised and wild-type empty capsids have essentially the same structure as intact virus. Cattle vaccinated with recombinant capsids showed sustained virus neutralisation titres and protection from challenge 34 weeks after immunization. This approach to vaccine antigen production has several potential advantages over current technologies by reducing production costs, eliminating the risk of infectivity and enhancing the temperature stability of the product. Similar strategies that will optimize host cell viability during expression of a foreign toxic gene and/or improve capsid stability could allow the production of safe vaccines for other pathogenic picornaviruses of humans and animals.

Highly potent delivery method of gp160 envelope vaccine combining lentivirus-like particles and DNA electrotransfer

Particulate antigen assemblies in the nanometer range and DNA plasmids are particularly interesting for designing vaccines. We hypothesised that a combination of these approaches could result in a new delivery method of gp160 envelope HIV-1 vaccine which could combine the potency of virus-like particles (VLPs) and the simplicity of use of DNA vaccines. Characterisation of lentivirus-like particles (lentiVLPs) by western blot, dynamic light scattering and electron microscopy revealed that their protein pattern, size and structure make them promising candidates for HIV-1 vaccines. Although all particles were similar with regard to size and distribution, they clearly differed in p24 capsid protein content suggesting that Rev may be required for particle maturation and Gag processing. In vivo, lentiVLP pseudotyping with the gp160 envelope or with a combination of gp160 and VSV-G envelopes did not influence the magnitude of the immune response but the combination of lentiVLPs with Alum adjuvant resulted in a more potent response. Interestingly, the strongest immune response was obtained when plasmids encoding lentiVLPs were co-delivered to mice muscles by electrotransfer, suggesting that lentiVLPs were efficiently produced in vivo or the packaging genes mediate an adjuvant effect. DNA electrotransfer of plasmids encoding lentivirus-like particles offers many advantages and appears therefore as a promising delivery method of HIV-1 vaccines. Keywords:VLP, Electroporation, Electrotransfer, HIV vaccine, DNA vaccine