Effect of needle length when immunizing obese adolescents with hepatitis B vaccine.
OBJECTIVE
Several studies have noted that obese adolescents and adults achieve lower titers of antibody in response to vaccines such as hepatitis B virus (HBV) vaccine. The objective of this study was to determine whether use of a longer (1.5-in) rather than a standard (1-in) needle to penetrate the thicker deltoid fat pad among obese youth would result in higher antibody titers after immunization against HBV.


METHODS
Obese adolescents from a large metropolitan area who had not previously received the HBV vaccine were randomly assigned to be immunized with HBV vaccine by using either a 1-inch or a 1.5-inch needle.


RESULTS
Those who were immunized with a 1.5-inch needle achieved significantly higher antibody titers to hepatitis B surface antigen (median titers: 1-inch = 189.8 mIU/mL, 1.5-inch = 345.4 mIU/mL; P = .03).


CONCLUSIONS
This finding supports the hypothesis that needle length accounts for a significant portion of the discrepancy in immune response to HBV vaccine that is seen among those with obesity.
MSEd, Baylor College of Medicine, Texas Children's Hospital, 6621 Fannin St, Suite 1710.00, Houston, TX 77030, USA. amym@bcm.edu
Amy B
AB
Middleman
Roberta
R
Anding
Celestine
C
Tung
D000293:Adolescent; D004867:Equipment Design; D005260:Female; D006510:Hepatitis B Antibodies / Q000097:blood*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D006801:Humans; D008297:Male; D009339:Needles; D009765:Obesity; D055815:Young Adult
D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines