Overview of new vaccines and technologies

Abstract

Molecular technology has given us a greater insight into the aetiology of disease, the functioning of the immune system and the mode of action of veterinary pathogens. The knowledge gained has been used to develop new vaccines with specific, reactive antigens which elicit protective immune mediated responses (humoral and/or cell mediated) in the host. These vaccines should not burden the immune system by initiating responses against non-essential antigens. However, the efficacy of these vaccines is only as good as the delivery technology or route used to present them to the immune system. Some vaccines, traditionally given by the parenteral route, are now given by the natural route; either orally or intranasally. Two major advantages, often interrelated, are the rapid onset of immunity and stimulation of the local, mucosal immunity. These new technologies are now making an impact on current vaccine development. The balance has to be found between what is technologically feasible and what will provide at least as good a protective immunity as current, conventional vaccines. As new and emerging diseases appear globally, new opportunities arise for molecular and conventional technologies to be applied to both the development and delivery of novel vaccines, as well as the improvement of vaccines in current use.

Mucosal antibody responses in experimental hookworm infection

“…The inability to detect intestinal IgA‐specific to AceES‐2 and other low molecular weight ES antigens suggests that the parasite may have evolved a strategy to subvert (or at least delay) the induction of secretory IgA responses to potentially vulnerable proteins. It also suggests that protocols specifically aimed at generating mucosal immune responses, such as oral vaccination (63–65), may be employed to induce or enhance protection in this model. This approach has shown promise using soluble adult worm extracts and recombinant AceES‐2 (28).…”

The dichotomy of pathogens and allergens in vaccination approaches

“…This vaccine has also demonstrated efficacy in other bird species such as the American robins ( Turdus migratorius ) ( Kilpatrick et al, 2010 ) and the fish crows ( Corvus ossifragus ; Turell et al, 2003 ). The first two DNA vaccines for veterinary use were granted US approval in 2005 for West Nile virus vaccine for horses and haematopoietic necrosis vaccine for farm-reared Atlantic salmon ( Chalmers, 2006 ). Even though there are no currently approved DNA vaccines for human use, as of May, 2014 there are 128 open trials listed on Clinicaltrials.Gov (2014) that involve DNA-based vaccines and therapies…”

“…To combat the growing epidemic the Dutch government chose an acellular vaccine which was used in primary vaccinations in 2005; however, the Health Minister advised that this decision was not based on recommendations and evidence provided by the Dutch Health Council, but on the need to appease parents and re-establish their confidence in the vaccine strategy ( Blume and Zanders, 2006 ). By contrast, in areas where any disease is endemic and the health system is overwhelmed, often the vaccination strategy proposed by governing bodies will be accepted by the population and acquiesced as mandatory ( Chalmers, 2006 ).…”

Applications of Plant-derived Vaccines for Developing Countries

“…These discrepancies were addressed in 1992 at the Children's Vaccine Initiative, a platform by which globally accessible oral vaccines are generated through an assembly of philanthropic groups in conjunction with the World Health Organization. The initiative set out to develop novel vaccines that are inexpensive, efficacious, safe, easy to transport to remote areas, and temperature stable [1,2]. The employment of plants as potential production and delivery platforms for the expression of vaccines to infectious diseases is one promising approach that emerged from this Initiative.…”