A report in the May issue of Archives of Pediatrics & Adolescent Medicine indicates that infants who receive the pneumococcal conjugate vaccine (PCV) after being given the grouping vaccine for diphtheria, polio, tetanus, pertussis and Haemophilus influenza type b (DPTaP-Hib vaccine) seem to experience less pain than other infants who are given the vaccinations in the reverse order.

Background facts sustained in the report imply that injections are the most frequent and painful medical procedures administered during childhood. “Multiple injections are routinely administered during a single visit to a physician,” the authors explain. “Because some vaccines cause more pain than others, the order in which they are given may affect the overall pain experience.” More than 90 percent of U.S. pediatricians reported in a current study that in the preceding year, at least one parent had declined to immunize their child, simply because of the pain inflicted by numerous vaccines. As a result, by reducing the pain related to vaccines, immunization could be improved, avoiding a resurgence of infectious diseases.

Between 2006 and 2007, a study including 120 healthy infants two to six months old going through a scheduled immunization at an outpatient clinic, was conducted by Moshe Ipp, M.B.B.Ch., of The Hospital for Sick Children, Toronto, Ontario, Canada, and colleagues. One half of the infants received the PCV before the DPTaP-Hib vaccine, the other half received it in the reverse order. While videotaping of the procedure, pain was evaluated according to the degree of the infant’s facial expressions, crying and body movements. On a scale of zero to ten, parents were also required to rate their children’s pain levels.

“Infant pain response during routine intramuscular vaccine injection was affected by the order of administration of the vaccine,” the authors remark. “Infants given the less painful DPTaP-Hib vaccine first followed by the more painful PCV experienced less pain overall when compared with those given the vaccines in the reverse order. In addition, pain increased from the first to the second injection, regardless of the order of vaccine injection.”

The authors indicate that according to the results, when two immunizations are administered, the least painful vaccine should be done first. The infant’s attention is focused on the procedure and activates pain processing centers in the brain after receiving the more painful shot. As a result, there is a more intense pain signal in reaction to any injection given later.

“Steps to minimize vaccine-related pain reduces the pain experienced by the child and improves the immunization experience of parents and health care workers,” the authors write in conclusion. “Varying the order of vaccine administration to reduce pain is a strategy that is simple and effective, cost-free and easily incorporated into clinical practice. In considering methods of reducing pain with vaccination, vaccine manufacturers must play a more integral role in attempting to produce vaccine formulations that are less painful.”

“Order of Vaccine Injection and Infant Pain Response”
Moshe Ipp, MBBCh; Patricia C. Parkin, MD; Naomi Lear, MD; Morton Goldbach, MD; Anna Taddio, PhD
Arch Pediatr Adolesc Med. 2009; 163[5]469-472.

Written by Stephanie Brunner (B.A.)