Immunisation safety: a priority of the World Health Organization's Department of Vaccines and Biologicals

Perceptions of vaccine safety in a global context

Given the serious consequences of low vaccine coverage, concerns and misconceptions need to be taken seriously and responded to appropriately to sustain accomplishments of immunization programmes. For parental decisions related to childhood vaccinations, it seems reasonable to assume that the cultural context of the immunization programme is of importance. This article is a short review of some recent studies of parental decision-making on vaccination in developed countries Kazaktstan, Uzbekistan and Northern Nigeria. Furthermore, an attempt is made to relate the findings in these studies to theoretical models of parental decision-making.

CONCLUSION

For the implementation of immunization programmes, it is important to develop an in-depth understanding of mechanisms underlying decisions to accept or reject the vaccination of a child. Theoretical models may aid in the understanding of these mechanisms.

Efficacy of measles and rubella vaccination one year after the nationwide campaign in Shiraz, Iran

BACKGROUND

The World Health Organization target for measles elimination in the Eastern Mediterranean Region was established in 2010. In Iran, the national measles-rubella campaign, targeting individuals aged 5-25 years, was initiated in December 2003.

METHODS

To evaluate the impact of the campaign after one year, 909 serum samples were collected in Shiraz, southern Iran, from a population aged 6-26 years, divided into five groups according to age. IgG antibodies were tested using ELISA for the measles and rubella antibodies, and the plaque reduction neutralization test (PRNT; measles) was used for samples with equivocal results.

RESULTS

Measles protective immunity reached 80.6%, 72.7%, 84.9%, and 87.5% and rubella immunity reached 91.0%, 99.6%, 99.6%, and 97.0% for the age groups 6-10, 11-15, 16-20, and 20-26 years, respectively. Seropositivity to the rubella virus in this population was high, especially in women of childbearing age (98.9%), thereby preventing congenital rubella infections. However for measles, it was significantly lower than the rate required to achieve >or=95% coverage for elimination.

CONCLUSIONS

These data indicate that an increase in immunization coverage by supplementary administration of a second dose of measles vaccine is needed to interrupt the endemic transmission of the measles virus.

Immunization and anesthesia - an international survey

BACKGROUND

There is no direct evidence of any major interaction between immunization and commonly used anesthetic agents and techniques in children, but it is possible that immunosuppression caused by anesthesia and surgery may lead to decreased vaccine effectiveness or an increased risk of complications. In addition, diagnostic difficulty may arise if a recently immunized child suffers from postoperative pyrexia or malaise.

AIM

The aim of this study was to ascertain anesthetists' attitudes and practices regarding anesthesia and immunization.

METHODS

We conducted an international survey of members of the Association of Paediatric Anaesthetists of Great Britain and Ireland (APAGBI) and the Society for Paediatric Anaesthesia of New Zealand and Australia (SPANZA).

RESULTS

Two hundred and ninety-six (52.1%) APAGBI and 86 (49.4%) SPANZA responses were analyzed. There was no consensus of approach to this theoretical risk among respondents. In total, 60% of respondents would anesthetize a child for elective surgery within 1 week of receiving a live attenuated vaccine, but 40% would not. Few hospitals have formal policies on this issue and government guidance is based on a lack of evidence for adverse events rather than positive evidence of safety.

CONCLUSIONS

There is a theoretical risk associated with anesthesia and surgery in recently immunized children. An international postal survey failed to find a consensus to this risk among pediatric anesthetists. From a risk management perspective, a review of the available evidence suggests that it would be prudent to adopt a cautious approach where the timing of elective surgery is discretionary. We therefore recommend that elective surgery and anesthesia should be postponed for 1 week after inactive vaccination and 3 weeks after live attenuated vaccination in children.

Issues and options for the safe destruction and disposal of used injection materials

It has long been known that the re-use of syringes can cause the spread of infections such as HIV and hepatitis. The production of disposable syringes was undertaken as a solution to the infection problem. In developing countries, however, there has been an unwanted result: the re-use and recycling of disposable syringes. One response has been "auto-disable" syringes that lock the plug and piston in place after a single use. These types of approaches, however, have resulted in greatly increased volumes of used injection materials. This is a particular problem in developing countries where contaminated medical wastes find their way into municipal garbage where people are known to scavenge and recycle. This poses obvious health risks, both in terms of direct exposure and environmental contamination. This study of issues and options for the safe destruction and disposal of used injection materials was undertaken using document analysis was to bring together and summarise approaches to the inter-related issues of "syringe re-use" and "clinical waste disposal". The authors suggest that holistic approaches to syringe use and clinical waste disposal need to be utilized in addressing the situation outlined. The focus is on technology and procedures that may be adaptable to rural areas in developing countries.

A global perspective on vaccine safety

"Immunization Safety" (i.e., ensuring and monitoring the safety of all aspects of immunization, including vaccine quality, storage and handling, vaccine administration and the disposal of sharps) remains a major challenge. Any vaccine safety issue, real or perceived, may lead to rumors and undermine confidence in vaccination and, ultimately, have dramatic consequences for immunization coverage and disease incidence. In 1999, WHO's Department of Vaccines and Biologicals launched the Immunization Safety Priority Project to establish a comprehensive system to ensure the safety of all immunizations given in national immunization programmes. The project aims at strengthening each country's capacity. The principal areas of activity of the project include: research and development of safer vaccines and safer and simpler vaccine delivery technologies; assurance of vaccine safety through quality control procedures and quality specifications; implementation of tools to ensure vaccine quality up to vaccine administration; access to safe and efficient vaccine administration technologies and their disposal; and identification and management of risks related to immunization. This report focuses on the latter area and highlights challenges and critical factors in establishing a safety profile for a vaccine and the importance and limits of post market surveillance. It presents some of WHO's supporting activities among which the establishment of a Global Advisory Committee on Vaccine Safety to provide an independent scientific assessment of vaccine safety issues. WHO has a role to play not only because of its technical and normative role but also because of its privileged relation with country authorities and its global vision and mandate and being perceived as neutral and free of conflicts of interest.

The challenge of achieving measles elimination in the eastern Mediterranean region by 2010

In 1997, the Eastern Mediterranean Region (EMR) of the World Health Organization adopted a resolution to eliminate measles by 2010. Of the 23 EMR member countries, 18 are polio-free and are building on this success to eliminate measles. The 5 countries where polio remains endemic are prioritizing polio eradication and working to improve measles control. Measles incidence has been reduced from 193/100,000 in 1981 to 6.8/100,000 in 2001. Supplemental vaccination campaigns for measles have been conducted since 1994 in 14 of the 18 polio-free countries. More than 50 million children have been immunized in these supplemental activities. However, in Afghanistan, Sudan, Somalia, Djibouti, and Pakistan, where 34% of the EMR population live, routine vaccination coverage for measles remains below 60% and measles deaths are estimated at 81,000 annually among children <5 years old. Significant resources must be allocated to these last 5 countries to achieve regional measles elimination by 2010.