Back to Annual Meeting Page		American Public Health Association 133rd Annual Meeting & Exposition December 10-14, 2005 Philadelphia, PA

Abstract #111927

Ran D. Balicer, MD, MPH, Epidemiology and Health Managment, Ben-Gurion University of the Negev, 27 Hagilgal st., Ramat-Gan, 52392, Israel, Itamar Grotto, MD, MPH, Epidemiology Department, Ben-Gurion University of the Negev, PO BOX 653, Beer-Sheva, 84105, Israel, 972 9 7434497, grotto@netvision.net.il, Nadav Davidovitch, MD, Health Systems Management, Faculty for Health Sciences, Ben Gurion University, P.O. Box 653, Beer Sheva, 84105, Israel, Alex Leventhal, MA, MPH, MPA, Head, Public Health Services, Ministry of Health, 20 King David Street, P.O. Box 1176, Jerusalem, 91010, Israel, Vered Yahalom, MD, MDA National Blood Services Center, Tel-Hashoner, Ramat-Gan, Israel, Michael Huerta, MD, MPH, Barzilai Medical Center, Ashkelon District Health Office, Ashkelon, 78306, Israel, and Dani Cohen, PhD, Epidemiology and Preventive Medicine, Tel-Aviv University, 32 Haim Levanon St, Tel-Aviv, 69978, Israel.

Background: In recent smallpox vaccination campaigns, Israel has adopted a unique vaccination technique of using vaccine droppers and surgical needles rather than the universally accepted bifurcated needle. Differences in vaccination techniques are known to impact clinical take rates, but these two techniques were never compared. The Israeli re-vaccination campaign resulted in a relatively high rate (35%) of failure to achieve clinical success ("take"), compared with similar campaigns in the US (<5%). We assessed the role of the Israeli vaccination technique in these differences.

Methods: An historical prospective study of an Israeli cohort, alternatively vaccinated using one of these two techniques. Multivariate regression models were used to compare "take" rates, vaccination site lesion size (a marker of immune response intensity) and reactogenicity by the vaccination technique used, while adjusting for potential confounders.

Results: "Take" was achieved in 41 of the 46 (91.4%) subjects vaccinated with bifurcated needles, and 64 of the 70 (89.1%) subjects vaccinated with beveled needles (p=0.751). Vaccination site lesion size and adverse event rates did not differ significantly between the two smallpox vaccination techniques studied. Take rates and lesion sizes increased as the time passed since previous vaccination increased (p=0.001 and p=0.05, respectively). The bifurcated needle is associated with considerable logistical advantages (quicker procedure, easily trainable frugal use of personnel) but is significantly more costly, compared with the use of surgical needles.

Conclusions: The differences in "take" rates between Israel and the US are most likely associated with differences in vaccine concentration and in host factors (mainly pre-existing residual immunity). This preliminary evidence may allow the economic and logistic considerations to guide health authorities worldwide in determining their default smallpox vaccination technique.

Learning Objectives:

• 1.Recognize the various factors that impact the clinical success of smallpox vaccination including the vaccination techniques used.
• 2.List the considerations affecting the choice of a national default vaccination technique, including epidemiological, logistical and economical aspects.
• 3.Determine the most appropriate vaccination technique to be used in one's country during emergency and routine smallpox vaccination campaigns.

Keywords: Bioterrorism, Immunizations

Presenting author's disclosure statement:
I have a significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.
Relationship: I serve in the Israel Defense Force as the Head of the Army Health Branch

Recorded presentation