12th Annual Conference on Vaccine Research

Jennifer O'Brien

Disclosures

Expert Rev Vaccines. 2009;8(9):1139-1142. 

In This Article

Abstract and Issues in Vaccine Safety

Abstract

The 12th Annual Conference on Vaccine Research, hosted by the National Foundation for Infectious Disease, attracted approximately 450 leaders in the fields of epidemiology, health economics, immunology and vaccinology, making it the largest scientific meeting devoted exclusively to vaccine research and technology. The conference highlighted recent issues in vaccine safety, including the history and design of a vaccine for rotavirus. Other topics included discussions of the synergies between veterinary and human vaccine development, updates on the development of vaccines for tuberculosis and malaria, and a comprehensive overview of immunization initiatives and goals for extending coverage of new and underused vaccines. Keynote remarks were provided by David Salisbury (Department of Health, London, UK) who outlined the aims and objectives of the Global Immunization Vision and Strategy (GIVS), an agenda created by the WHO and UNICEF. Salisbury highlighted the four primary aims of GIVS: immunize more people against more diseases, introduce a range of newly available vaccines and technologies, integrate other critical health interventions with immunization, and manage vaccination programs within the context of global interdependence. The GIVS initiative spans the time period of 2006-2015.

Issues in Vaccine Safety

Vaccine clinical trials are important in assessing not only the efficacy of a vaccine, but also any health risks posed by the vaccine itself. This surveillance is important both before and after a vaccine has been licensed, and systems are needed to ensure that these data can be collected and communicated properly. The goal of these efforts is to create both highly efficacious and safe vaccines.

Rotavirus - a leading cause of diarrheal disease worldwide - accounts for approximately 600,000 child deaths per year. In 1998, following two decades of research, a rhesus rotavirus vaccine, Rotashield®, was licensed for use in children in the USA. A year later, however, the vaccine was withdrawn: researchers detected a rare association between the vaccine and intussusception (IS), a potentially fatal invagination of the small intestine. Umesh Parashar (CDC, Atlanta, GA, USA) discussed the costs and benefits of this decision. In the USA, the vaccine resulted in 400,000 fewer rotavirus-related doctor visits and 40,000 fewer hospitalizations, while the number of hospital visits due to IS increased among the vaccinated group by 700. Translated into developing country settings where the burden of rotavirus is quite high, Rotashield had the potential to prevent one in 250 child deaths (600,000 per year); the risks would have probably included one case of IS in every 30,000 vaccinated children. Parashar noted that this experience influenced the design and development of subsequent vaccines for rotavirus; new products had to undergo large-scale, time-consuming and expensive trials of more than 60,000 infants. As of 2006, two vaccines - RotaTeq® and Rotarix® - had been approved and introduced into several national immunization programs. Not until 2009, however, were the vaccines considered safe and efficacious for children in south Asia and sub-Saharan Africa, the two areas with the greatest burden of rotavirus. Postlicensure monitoring of both vaccines is ongoing to further guard against health risks.

Paul Offit (Children's Hospital of Pennsylvania, PA, USA) discussed the role of the scientific community in identifying and communicating adverse events following immunization (AEFI). Offit focused on the 1998 paper published by the Lancet, which claims that the combined measles-mumps-rubella (MMR) vaccine caused autism. Since that publication, Offit noted that 12 separate studies have concluded that MMR does not cause autism. Despite these results, fear and skepticism surrounding the MMR vaccine still exist and are influencing parents as they decide whether or not to vaccinate their children. Offit encouraged members of the scientific community to assume a greater role in communicating health information to the general public. Steven Black (Cincinnati Children's Hospital, OH, USA) discussed the need for new approaches to assessing low-frequency AEFI. Given modern communication systems, AEFI of any origin can be communicated rapidly, requiring high-quality methods to survey, verify and respond to these events. Although some passive reporting systems exist, such as the Vaccine Adverse Event Reporting System, Black argued that they are plagued by under-reporting, misclassification, and reporter bias. He called for further investigation into how to collect these data and respond to them effectively.

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