Universal Vaccines : shifting to one for many

Abstract

Human vaccines, with their exquisite antigenic specificity, have greatly helped to eliminate or dramatically abate the incidence of a number of historical and current plagues, from smallpox to bacterial meningitis. Nonetheless, as new infectious agents emerge and the number of vaccine-preventable diseases increases, the practice and benefits of single-pathogen-or disease-targeted vaccination may be put at risk by constraints of timely production, formulation complexity, and regulatory hurdles. During the last influenza pandemic, extraordinary efforts by vaccine producers and health authorities have had little or no influence on disease prevention or mitigation. Recent research demonstrating the possibility of protecting against all influenza A virus types or even phylogenetically distant pathogens with vaccines based on highly conserved peptide or saccharide sequences is changing our paradigm. "Universal vaccine" strategies could be particularly advantageous to address protection from antibiotic-resistant bacteria and fungi for which no vaccine is currently available. CURRENT VACCINES: MERITS AND CONSTRAINTS

Adjuvants and alternative routes of administration towards the development of the ideal influenza vaccine

“…From this viewpoint, the most promising approach is that regarding the production of vaccines based on more conserved antigenic epitopes than the highly variable surfaces of the HA and NA proteins, such as the extracellular portion of the M2 protein, the nucleoprotein and some conserved domains of the HA. 27,[117][118][119] Positive preliminary results for a "universal target" antigen vaccine against influenza have been achieved using the extracellular portion of the M2 protein in the mouse model, in which antibodies elicited by immunization, directed to this domain, have been shown to confer protection against a range of influenza strains: 120 the magnitude of this immune response, in other animal models, remains to be further investigated and the same will be assessed in ongoing clinical trials, with many key-points of this very promising immunization strategy becoming clearer in the near future.…”

A universal influenza vaccine: Where are we in the pursuit of this “Holy Grail”?

“…Clearly, a universal influenza vaccine, one that would be effective against all (or most) circulating influenza virus strains, would obviate the need for annual reformulation and repeated annual immunizations, and would significantly reduce the burden, both human and economic, of the disease. 1 Global research and development efforts towards the development of such a universal flu vaccine have gained pace in recent years, and the prospect of such a vaccine reaching the market in the next few years is now increasingly becoming more tangible.…”

The surge of universal influenza vaccines

“…There is large consensus that properly used vaccines have been one of the greatest successes of modern medicine. The major problem now appears to be in expanding the practice of vaccination in vaccine non-compliant areas and broaden the vaccines spectrum to target many other highly incident and lethal, diseases [1,2].…”

“…As discussed elsewhere [2], we should nonetheless recognize that some of the current vaccines have limitations, and their benefits are challenged by several factors that, if dealt with complacently, could undermine people's confidence in the vaccination as a safe and effective health measure. An incomplete list of the above factors is reported in Table 1.…”