ATLANTA — Despite new data suggesting that current Centers for Disease Control and Prevention recommendations regarding needle length for intramuscular vaccine injections might be flawed, the CDC's Advisory Committee on Immunization Practices favors maintaining the current recommendations.
The new data published this year by Dr. William Lippert and associates suggest that the currently recommended needle lengths increase risk of overpenetration and striking of bone and periosteum (Pediatrics 2008;122:e556–63). In some cases, the CDC recommendations are nearly twice what the study authors recommended, based on their review of 250 diagnostic MRI and CT scans. For example, in boys weighing 140 kg or less and in girls weighing 115 kg or less, the authors recommended a 5/8-inch needle length, while the current CDC recommendations call for a 1-inch needle length in these groups, according to Dr. Andrew Kroger of the CDC and ACIP's General Recommendations Working Group, which proposed the revision at ACIP's fall meeting.
Most working group members favored changing the general recommendations to “partially adopt” the new data by adding footnotes that incorporate the new data, Dr. Kroger said.
A proposed footnote states that “some experts recommend a needle shorter than 1 inch (25 mm) for children/adolescents 3 years through 18 years who weigh less than 140 kg (males) or less than 115 kg (females).”
However, several ACIP members argued against any change, saying that in years of practice they have not seen the types of complications noted in the study and arguing that the proposed change complicates matters for health care providers.
“Overall, I think that any change is unworkable,” said Dr. Michael S. Marcy of the UCLA Center for Vaccine Research in Torrance, Calif.
The Lippert study is “interesting, but perhaps irrelevant,” Dr. Marcy said, noting that a recommendation for shorter needle length for some children might outweigh any benefits—especially given the fact that an increasing number of pediatric patients are overweight or obese, which could lead to increased risk of subcutaneous vs. intramuscular injection with use of shorter needles.
The committee asked the working group to maintain the current recommendations in the updated general recommendations report the group is currently drafting. The first half of the revised report was presented at the meeting.
The last report, adopted in 2006, includes a grid calling for the use of a 5/8-inch needle in newborns injected at the anterolateral thigh, a 1-inch needle in those aged 1–12 months injected at the anterolateral thigh, a 1- to 1 1/4-inch needle in those aged 1–2 years injected at the anterolateral thigh or a 5/8- to 1-inch needle in those injected at the deltoid muscle of the arm, and a 5/8- to 1-inch needle in those aged 3–18 years injected at the deltoid muscle of the arm or a 1- to 1 1/4-inch needle in those injected at the anterolateral thigh.
Although the grid does not emphasize injection technique, the text of the recommendation in the report does address technique, Dr. Kroger noted.
The second half of the revised draft of the General Recommendations report, which addresses immunization issues relevant to all vaccines and which addresses topics ad hoc that cannot be attributed to a single vaccine, will be presented to ACIP in February 2009. The revised report is scheduled for publication in December 2009.