Potential use of inflammation and early immunological event biomarkers in assessing vaccine safety.

Highly effective vaccines have traditionally been designed in a rather empirical way, often with incomplete understanding of their mode of action. Full assessment of efficacy and reactogenicity takes time and, as a result, vaccine introduction to the market is usually slow and expensive. In addition, in rare cases, unacceptable reactogenicity may only become apparent after years of development or even widespread use. However, recent advances in cell biology and immunology offer a range of new technologies and systems for identifying biological responses or "biomarkers" that could possibly be used to evaluate and predict efficacy and safety during vaccine development and post-marketing surveillance. This report reflects the conclusions of a group of scientists from academia, regulatory agencies and industry who attended a conference on the potential use of biomarkers to assess vaccine safety which was held in Baltimore, Maryland, USA, from 10 to 11 May 2012 and organized by the International Association for Biologicals (IABS). The conference focused particularly on determining which biomarkers might relate to vaccine efficacy and reactogenicity and whether our knowledge base was sufficiently robust at this time for the data to be used for decision-making. More information on the conference output can be found on the IABS website, http://www.iabs.org/.

Mode of action of adjuvants: implications for vaccine safety and design.

For decades, the search for new vaccine adjuvants has been largely empirical. A series of new adjuvants and related formulations are now emerging that are acting through identified immunological mechanisms. Understanding adjuvant mechanism of action is crucial for vaccine design, since this allows for directing immune responses towards efficacious disease-specific effector mechanisms and appropriate memory. It is also of great importance to build new paradigms for assessing adjuvant safety at development stages and at regulatory level. This report reflects the conclusions of a group of scientists from academia, regulatory agencies and industry who attended a conference, organized by the International Association for Biologicals (IABS), on the mode of action of adjuvants on 29-30 April 2010 in Bethesda, Maryland, USA, particularly focusing on how understanding adjuvants mode of action can impact on the assessment of vaccine safety and help to develop target-specific vaccines. More information on the conference output can be found on the IABS website, http://www.iabs.org/.

Viral hepatitis: some reflections on a personal journey.

The pathway to understanding a new field is often more fraught with issues than it appears from later accounts. The series of coincidences that led to my involvement in the field of viral hepatitis and the circuitous pathway leading to the development of the first hepatitis A vaccine is described from a personal perspective.

Influenza vaccine strain selection and recent studies on the global migration of seasonal influenza viruses.

Annual influenza epidemics in humans affect 5-15% of the population, causing an estimated half million deaths worldwide per year [Stohr K. Influenza-WHO cares. Lancet Infectious Diseases 2002;2(9):517]. The virus can infect this proportion of people year after year because the virus has an extensive capacity to evolve and thus evade the immune response. For example, since the influenza A(H3N2) subtype entered the human population in 1968 the A(H3N2) component of the influenza vaccine has had to be updated almost 30 times to track the evolution of the viruses and remain effective. The World Health Organization Global Influenza Surveillance Network (WHO GISN) tracks and analyzes the evolution and epidemiology of influenza viruses for the primary purpose of vaccine strain selection and to improve the strain selection process through studies aimed at better understanding virus evolution and epidemiology. Here we give an overview of the strain selection process and outline recent investigations into the global migration of seasonal influenza viruses.

The global circulation of seasonal influenza A (H3N2) viruses.

Antigenic and genetic analysis of the hemagglutinin of approximately 13,000 human influenza A (H3N2) viruses from six continents during 2002-2007 revealed that there was continuous circulation in east and Southeast Asia (E-SE Asia) via a region-wide network of temporally overlapping epidemics and that epidemics in the temperate regions were seeded from this network each year. Seed strains generally first reached Oceania, North America, and Europe, and later South America. This evidence suggests that once A (H3N2) viruses leave E-SE Asia, they are unlikely to contribute to long-term viral evolution. If the trends observed during this period are an accurate representation of overall patterns of spread, then the antigenic characteristics of A (H3N2) viruses outside E-SE Asia may be forecast each year based on surveillance within E-SE Asia, with consequent improvements to vaccine strain selection.

A global pandemic influenza vaccine action plan.

In case of an influenza pandemic, the world will be in a situation where potential vaccine supply will fall short by several billion doses from global needs. The World Health Organization (WHO) convened in Geneva on May 2-3, 2006 a consultation of all stakeholders in influenza vaccines and immunization to identify practical solutions to fill this gap. The consultation resulted in a global action plan outlining promising specific strategies to increase influenza vaccine production and surge-capacity before and during an influenza pandemic. Although the timing and severity of the next influenza pandemic cannot be predicted, vaccines are considered the one of the most important medical interventions for reducing morbidity and mortality if and when such an event occurs. Despite this acknowledged role, current limitations on influenza vaccine manufacturing capacity mean that, should a pandemic virus emerge in the near future, vaccine supplies would fall short of the anticipated global demand by several billion doses. Concern about this situation was formally acknowledged in May 2005, when the World Health Assembly approved a resolution [1] on strengthening pandemic influenza preparedness and response. That resolution called on the World Health Organization (WHO) to seek solutions with international and national partners, including the private sector, to reduce the present global shortage of influenza vaccines. More specifically, the resolution asked WHO to look at strategies for economizing on the use of antigen and transferring production technologies from industrialized to developing countries. In response to this request, WHO convened a consultation from 2-3 May 2006 attended by representatives of the major stakeholders in the area of influenza vaccines and immunization. The consultation had two main objectives: (1) To prepare a global action plan with specific short-, medium-, and long-term activities designed to increase influenza vaccine production and surge-capacity, to identify key obstacles and driving forces, and to estimate funding needs.(2) To strengthen the engagement and collaboration of key partners and stakeholders.

The pros and cons of immunisation -- Paper two: the importance of immunisation.

Like other medicine, all vaccines have some side effects or complications; in general the incidence and severity of complications is lower than for pharmaceuticals. When considered on a population basis, the incidence of serious complications of vaccination is minute, when compared with the outcome of natural infection. Enlightened governments, which promote immunisation as a means of minimising the impact of infectious diseases in their communities, also accept the responsibility for any adverse events which can be demonstrated to be vaccine related, and provide compensation and care for people who are affected.