Selected Major Issues in Vaccine Safety

Abstract

Recent examples of the major public health benefits of vaccination include global reductions in measles mortality and record low levels of vaccine-preventable diseases in the United States. Nevertheless, real or perceived vaccine safety issues may adversely impact vaccine programs. Robust post-licensure safety monitoring which combines active and passive surveillance with use of standardized case definitions for adverse events is the scientific basis for assessing safety concerns. Emerging aspects of vaccine safety science include clinical research networks and vaccine risk communication research. Current high-profile safety issues include the introduction of 2 second-generation rotavirus vaccines, for which close monitoring of intussusception is necessary. To date, data from the US do not indicate an elevated risk associated with the licensed Merck vaccine (Rotateq®). An issue of global interest is the use of thimerosal as a preservative in multi-dose vaccine vials. Comprehensive independent reviews as well as recently published research have reaffirmed the lack of association between thimerosal and neuro-developmental disorders, including autism. Expanded use of annual influenza vaccine and pandemic planning in the developed or developing world should include plans for safety monitoring. As the number of newly licensed vaccines increases, potentially preventable vaccine administration errors and post-vaccination events such as syncope are being increasingly recognized. Primary care clinicians and others involved in giving vaccines should follow proper vaccine storage, handling and administration procedures and should participate in adverse event following immunization (AEFI) reporting systems. The Brighton Collaboration provides another outlet, which interested clinicians and researchers can participate in, increasing the global vaccine safety knowledge base. Increased knowledge of and participation in vaccine safety systems at all levels of health care systems in both developed and developing country settings will allow vaccines to maintain their excellent safety track record, as safety data is used to improve immunization practice.