Obstacles to vaccination of animals and prospective solutions.

On the 17th of October 2019, a workshop was held at Wageningen Bioveterinary Research in Lelystad, the Netherlands, to discuss the obstacles to vaccination in the veterinary field. Participants from academia, OIE, FAO, EC, EMA, USDA, national regulatory and veterinary health authorities, and the animal health industry discussed how availability and access to animal vaccines can be improved not just in the EU and US but also in Low to Middle Income Countries (LMIC) across the world and agreed that this requires innovations in both the scientific and the regulatory field. The workshop called for engaging all stakeholders to improve regulatory acceptance of novel vaccine technologies and encourage their registration. There is a need for better mutual understanding between academia, industry and regulators, and more openness to discuss framework, requirements, and product authorisations, and to converge the regulatory rules between regions. The next leap forward could be a broader application of novel technologies using RNA- or DNA-based vaccine platforms, where the "backbone" is maintained, while the gene of interest coding for an immunogenic protein can be exchanged in a standardised manner. This approach enables rapid response in outbreak situations and should lower the risk and cost of vaccine development.

DNA Vaccines: A Strategy for Developing Novel Multivalent TB Vaccines.

Multivalent DNA vaccines that are delivered by electroporation (EP) through muscle tissue provide a novel method for eliciting immunity against tuberculosis (TB) as well as a broad range of diseases including HIV and cancers. Proper plasmid construction containing suitable protective TB antigens capable of evoking desired vaccine-induced responses would lead to the appropriate induction of both humoral and cellular immunity. DNA vaccines are safe and of low cost in comparison to traditional vaccines while also providing potentially effective prophylactic or therapeutic modalities against currently untreatable diseases. Here, we describe the steps for developing a rational multivalent TB DNA vaccine delivered with intramuscular EP in mice.

Inovio.

A Pennsylvania company hopes to turn synthetic DNA vaccines into rapid response agents against flu epidemics and cancer.

European Union vaccine research--an overview.

Recent developments in vaccine research provide new momentum for an important area in health innovation. Particularly interesting are novel DNA vaccine approaches, many of which are already under clinical investigation. The Framework Programmes of the European Union play an important role in supporting collaborative efforts in vaccine research to develop new and better vaccines and bring them to the market. With a timely strategic reorientation towards a sustainable investment in innovation, the current seventh Framework Programme will help to bring large industry and small and medium-sized enterprises (SME) on board and foster partnership between stakeholders. As the first human DNA vaccines progresses through the development pipeline, more and more questions revolve around licensing and regulation and appropriate guidelines are being developed.

3rd Global Vaccine Congress.

Singapore was the location of the 3rd Global Vaccine Congress on 4-6 October 2009, and it provided a suitable place for sharing a range of developments, concepts and challenges associated with vaccines. One of the major goals of this meeting was to present a broad and balanced program of research, development, production, clinical testing and delivery of vaccines to people living in different parts of the world. This report contains an overview of recent developments in the vaccine field against a range of infections and disease situations that were presented during the meeting. The highlights included challenges to the current constraints on the timely and cost-effective development of vaccines and a focus on the H1N1 influenza pandemic concerns. The meeting also generated presentations that challenged the regulatory and political status quo in order to expand global access to vaccines and facilitate speedier and more cost-effective development of new vaccines.

Bringing DNA vaccines closer to commercial use.

Progress in the application of DNA vaccines as an immunization protocol is evident from the increasing number of such vaccines under evaluation in clinical trials and by the recent approval of several DNA vaccine products for veterinary applications. DNA vaccine technology offers important therapeutic and commercial advantages compared with conventional approaches, including the opportunity to target pathogens characterized by significant genetic diversity using a safe immunization platform, and the ability to use a simple, rapid and well-characterized production method. However, further optimization of DNA vaccine technology through the use of improved constructs, delivery systems and immunization protocols is necessary to clinically achieve the promising results that have been demonstrated in preclinical models.

DNA vaccines in veterinary use.

DNA vaccines represent a new frontier in vaccine technology. One important application of this technology is in the veterinary arena. DNA vaccines have already gained a foothold in certain fields of veterinary medicine. However, several important questions must be addressed when developing DNA vaccines for animals, including whether or not the vaccine is efficacious and cost effective compared with currently available options. Another important question to consider is how to apply this developing technology in a wide range of different situations, from the domestic pet to individual fish in fisheries with several thousand animals, to wildlife programs for disease control. In some cases, DNA vaccines represent an interesting option for vaccination, while in others, currently available options are sufficient. This review will examine a number of diseases of veterinary importance and the progress being made in DNA vaccine technology relevant to these diseases, and we compare these with the conventional treatment options available.

Development of a vaccine against pandemic influenza viruses: current status and perspectives.

The constant threat of a new influenza pandemic, which may be caused by a highly pathogenic avian influenza virus, necessitates the development of a vaccine capable of providing efficient, long-term, and cost-effective protection. Proven avenues for the development of vaccines against seasonal influenza as well as novel approaches have been explored over the past decade. Whereas significant insights are consistently being made, the generation of a highly efficient and cross-protective vaccine against the future pandemic influenza strain remains as the ultimate goal in the field. In this review, we re-examine these efforts and outline the scientific, political, and economic problems that befall this area of biotechnological research.

Rabies DNA vaccines for protection and therapeutic treatment.

DNA vaccines have shown efficacy in preclinical animal models in preventing or even treating a variety of diseases caused by infectious agents, malignancies or immunological disorders. One of the main perceived advantages of DNA vaccines for use in less developed countries is their low cost. Nevertheless, in general, immune responses elicited by DNA vaccines are less potent than those induced by traditional vaccines or second generation viral recombinant vaccines, and their efficacy in human Phase I trials has been disappointing. DNA vaccines have shown good efficacy in preventing rabies in some experimental animal models; their performance in postexposure treatment has been less impressive. Considering that rabies is nearly always fatal, efficacious vaccines are available and treatment in most cases is initiated after exposure, the development of current DNA vaccines to rabies for use in humans is, at the current time, not appropriate.

Spermine compaction is an efficient and economical method of producing vaccination-grade DNA.

Plasmid DNA inoculations can induce both humoral and cellular immunity, and this technique is now being employed in developing vaccination regimens for a large number of applications. DNA vaccination studies require the preparation of large amounts of purified plasmid DNA with low endotoxin contamination, and the cost burden for multiple injections, multiple animal or large animal studies is significant. We recently reported that selective compaction with spermine can be used to purify large quantities of DNA. We wanted to determine whether this method would produce DNA suitable for vaccination. Endotoxin levels for spermine-compacted DNA were 0.3+/-0.01 endotoxin units (EU)/microg, well within the accepted range (less than 3 EU/microg) for in vivo use. When injected intramuscularly into mice, column-purified and spermine-compacted DNA induced an equivalent antigen-specific CD8+ T-cell response. The labor and time involved in purifying 5 mg of DNA by each method were similar, but the cost of spermine-compacted DNA was only 20% of the cost of column-purified DNA. We conclude that spermine compaction is an efficient and economical method for preparing vaccination-grade DNA.

[Vaccination of medical personnel against hepatitis B: epidemiological and socio-economic aspects]. / Vaktsiantsiia meditsinskikh rabotnikov protiv gepatita B: épidemiologicheskie i sotsial'no-ékonomicheskie aspekty.

Epidemiological and social aspects of the vaccinal prophylaxis of medical personnel against hepatitis B are discussed on the basis of the morbidity analysis in viral hepatitis, the results of dynamic screening for the presence of hepatitis B markers and the state of postvaccination immunity. The reactogenicity and immunogenicity of the vaccine "Euvax B", as well as the socio-economic effect of vaccinal prophylaxis, are evaluated.

New oral DNA vaccine funded for trials.

A new kind of vaccine uses a harmless bacterium to deliver selected parts of HIV to immune cells in the intestinal membranes.

Nonhuman primate models to evaluate vaccine safety and immunogenicity.

When considering preclinical studies to evaluate the safety and immunogenicity of putative vaccine candidates, such as nucleic acid vaccines, species most closely related to humans should be considered. Phylogenetically, the great apes (chimpanzees, orangutans, gorillas, and gibbons) are most closely related to humans. However, the great apes, which diverged from humans over 5 million years ago, represent endangered or threatened species that limits their utility in preclinical studies. In addition, cost considerations for using great apes in biomedical studies represents another serious limitation. The Old World monkeys, (macaques, baboons, mandrills, and mangabeys), diverged from humans over 15 million years ago. A number of the Old World monkey species including rhesus, cynomolgus, and African green monkeys, have also been employed in biomedical research to evaluate vaccine safety and immunogenicity. New World monkeys (aotus, owl, cebus monkeys, and marmosets) are the most phylogenetically divergent from humans, yet they have also been utilized to develop nonhuman primate models for a number of human infectious diseases and tumors. The advantages and disadvantages in selecting a particular nonhuman primate species for studies to evaluate DNA vaccine safety and immunogenicity are briefly discussed. Comparative immunology, reproductive physiology, endogenous infectious agents, and cost considerations are briefly described.