TITLE

Frequency of Adverse Events after Vaccination with Different Vaccinia Strains

AUTHOR(S)
Kretzschmar, Mirjam; Wallinga, Jacco; Teunis, Peter; Xing, Shuqin; Mikolajczyk, Rafael
PUB. DATE
August 2006
SOURCE
PLoS Medicine;Aug2006, Vol. 3 Issue 8, pe272
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Background:Large quantities of smallpox vaccine have been stockpiled to protect entire nations against a possible reintroduction of smallpox. Planning for an appropriate use of these stockpiled vaccines in response to a smallpox outbreak requires a rational assessment of the risks of vaccination-related adverse events, compared to the risk of contracting an infection. Although considerable effort has been made to understand the dynamics of smallpox transmission in modern societies, little attention has been paid to estimating the frequency of adverse events due to smallpox vaccination. Studies exploring the consequences of smallpox vaccination strategies have commonly used a frequency of approximately one death per million vaccinations, which is based on a study of vaccination with the New York City Board of Health (NYCBH) strain of vaccinia virus. However, a multitude of historical studies of smallpox vaccination with other vaccinia strains suggest that there are strain-related differences in the frequency of adverse events after vaccination. Because many countries have stockpiled vaccine based on the Lister strain of vaccinia virus, a quantitative evaluation of the adverse effects of such vaccines is essential for emergency response planning. We conducted a systematic review and statistical analysis of historical data concerning vaccination against smallpox with different strains of vaccinia virus.Methods and Findings:We analyzed historical vaccination data extracted from the literature. We extracted data on the frequency of postvaccinal encephalitis and death with respect to vaccinia strain and age of vaccinees. Using a hierarchical Bayesian approach for meta-analysis, we estimated the expected frequencies of postvaccinal encephalitis and death with respect to age at vaccination for smallpox vaccines based on the NYCBH and Lister vaccinia strains. We found large heterogeneity between findings from different studies and a time-period effect that showed decreasing incidences of adverse events over several decades. To estimate death rates, we then restricted our analysis to more-recent studies. We estimated that vaccination with the NYCBH strain leads to an average of 1.4 deaths per million vaccinations (95% credible interval, 0-6) and that vaccination with Lister vaccine leads to an average of 8.4 deaths per million vaccinations (95% credible interval, 0-31). We combined age-dependent estimates of the frequency of death after vaccination and revaccination with demographic data to obtain estimates of the expected number of deaths in present societies due to vaccination with the NYCBH and Lister vaccinia strains.Conclusions:Previous analyses of smallpox vaccination policies, which rely on the commonly assumed value of one death per million vaccinations, may give serious underestimates of the number of deaths resulting from vaccination. Moreover, because there are large, strain-dependent differences in the frequency of adverse events due to smallpox vaccination, it is difficult to extrapolate from predictions for the NYCBH-derived vaccines (stockpiled in countries such as the US) to predictions for the Lister-derived vaccines (stockpiled in countries such as Germany). In planning for an effective response to a possible smallpox outbreak, public-health decision makers should reconsider their strategies of when to opt for ring vaccination and when to opt for mass vaccination.
ACCESSION #
23456989

 

Related Articles

  • Health workers to be vaccinated for smallpox. Krisberg, Kim // Nation's Health;Feb2003, Vol. 33 Issue 1, p1 

    Reports on the plan of public health and emergency response workers to vaccinate their personnel against smallpox following the recommendation of U.S. President George W. Bush in December 2002 that key staff be protected from the disease. Cooperation of U.S. Department of Health and Human...

  • US smallpox vaccination off to slow start. Lo, Pierrette // Nature Medicine;Mar2003, Vol. 9 Issue 3, p249 

    Reports on smallpox vaccination program in the U.S. Centers for Disease Control and Prevention's shipment of small pox vaccine to 40 states and counties; Reluctance of local health agencies to divert resources away from other public health programs.

  • SMALLPOX: SHOULD YOU BE VACCINATED? Dittmar, Mary Jane // Fire Engineering;Mar2003, Vol. 156 Issue 3, p65 

    Reports on the United States government's launching of the national smallpox vaccination program. Phases of the program for civilian vaccinations; Factors that should be considered by an individual in deciding to get vaccinated; Characteristics of the smallpox disease; Exposure potential; Legal...

  • Our Finest Hour. Clinton, Patrick // BioPharm International;Jan2003, Vol. 16 Issue 1, p10 

    Comments on the significance of eliminating smallpox in the U.S. Survey designed to test what the public knows about smallpox and smallpox vaccination; Role of public health management and containment in eliminating smallpox; Belief of Americans that smallpox can be treated; Contribution of...

  • Smallpox Vaccine in Persons with Eczema. Morantz, Carrie; Torrey, Brian // American Family Physician;4/15/2003, Vol. 67 Issue 8, p1839 

    Relates the warning issued by the National Eczema Association for Science and Education in April 2003 for people with eczema or atopic dermatitis not to receive the smallpox vaccine. Basis of the health advisory; Prevalence of the skin disease in the U.S.; Signs of exposures.

  • Dermatologists are key players in smallpox war. Kapes, Beth // Dermatology Times;Jan2004, Vol. 25 Issue 1, p18 

    Focuses on the role of dermatologists in implementing small pox vaccination programs in the United States. Key to the successful implementation of a broad smallpox vaccination program; Involvement of the Department of Defense in the implementation of the program.

  • Risks of serious complications and death from smallpox vaccination: A systematic review of the United States experience, 1963-1968. Aragón, Tomás J.; Ulrich, Skylar; Fernyak, Susan; Rutherford, George W. // BMC Public Health;2003, Vol. 3 Issue 1, p26 

    Background: The United States (US) has re-instituted smallpox vaccinations to prepare for an intentional release of the smallpox virus into the civilian population. In an outbreak, people of all ages will be vaccinated. To prepare for the impact of large-scale ring and mass vaccinations, we...

  • Death sparks smallpox vaccine investigation.  // Australian Nursing Journal;May2003, Vol. 10 Issue 10, p15 

    Reports on the investigation made by the U.S. health officials whether small-pox vaccination contributed to the death of a Maryland nurse in March 2003 from heart complications and serious side effects in people inoculated against the smallpox virus. Agency which has been spearheading a...

  • Smallpox: We'll Soon Have Enough Vaccine...  // Child Health Alert;May2002, Vol. 20, p1 

    Focuses on smallpox vaccine in the U.S.

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics