A Shot in the Thigh – Not the Arm

DTaP vaccine given in the thigh has lower reaction risk than when given in the arm

(RxWiki News) Common side effects of vaccines are soreness and redness where a child gets the shot. For one common vaccine, it may be better to inject it in the thigh rather than the arm.

A recent study found that giving the DTaP shot in the thigh often had less of a local reaction than giving it in the arm.

The DTaP is a vaccine that offers protection against three diseases: diphtheria, tetanus and pertussis (whooping cough). It is first given at 2 months of age, and children receive four boosters through age 6.

"Follow the CDC's vaccine schedule."

The study, led by Lisa A. Jackson, MD, MPH, of the Group Health Research Institute in Seattle, aimed to find out whether it made a difference if a child received vaccine injections in the arm or in the thigh.

Dr. Jackson and colleagues used data stored in the Vaccine Safety Datalink regarding 1.4 million children who received about 6 million injected vaccines between 2002 and 2009.

The researchers looked at the local reactions associated with the inactivated flu vaccine, the hepatitis A vaccine and the DTaP. They included the 5.6 million vaccine doses in the data which had information on whether the shot was given in the arm or leg.

The researchers then looked at which children had a "medically attended local reaction" within the next five days after receiving the vaccine.

These reactions were ones in which the child returned to a doctor for a variety of possible reactions, including a swollen limb, skin inflammation, pain in the limb, any other skin disorder or allergic reaction, infection or other complications from the shot.

The researchers did not include data for children with pre-existing conditions related to these types of reactions.

The researchers found that local reactions were not very common with the hep A and flu vaccines. They also did not find a difference in reactions whether these vaccines were given in the thigh or in the arm.

However, local reactions from the DTaP were more common, especially when the shot was given in children's arms.

Children aged 12 to 35 months were almost twice as likely to experience a local reaction from the DTaP shot if they got the shot in their arm instead of their thigh.

Children aged 3 to 6 years old were also a little more likely to see a reaction in the arm than in the thigh from the DTaP. However, among older children, the difference in reactions could have been due to chance.

The researchers therefore concluded that pediatricians and other healthcare providers should continue to follow the current recommendations of giving any intramuscular vaccines in the thigh for children under 3 years old.

The study was published January 14 in the journal Pediatrics. The research was funded by the US Centers for Disease Control and Prevention through America's Health Insurance Plans.

Dr. Jackson has received research funding from Sanofi Pasteur, Pfizer, Novartis and GlaxoSmithKline. Two other authors have received research funds from MedImmune and from GSK, and a third has received research funds from Sanofi Pasteur, MedImmune, Pfizer, Novartis, GSK and Merck. No other disclosures were noted for the other nine authors.

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Review Date: 
January 17, 2013
Last Updated:
January 20, 2013