Diamond said that providing access is key to improving these rates even further, and that education has to follow the access. If people don't realize that low- or no-cost vaccines are available, immunization rates won't go up, he pointed out.
"We need to ensure access and professional cooperation, and provide more outreach to the community," said Diamond.
"Vaccines are an important step to providing a healthy environment for your child," he noted.
Two other studies in the same issue of the pediatric journal also examined vaccine-related issues. One found that international records of immunizations for children adopted from other countries aren't reliable indicators of whether or not children have been vaccinated.
For example, immunity in some of the children against certain types of polio was only around 50 percent. The study included children adopted from China, Russia and Guatemala. Children from China were the most likely to be lacking protective immunity. The researchers suggested that children adopted from other countries should be tested to assess their protective immunity, and if necessary, be revaccinated.
A third study looked at the order in which two immunizations are given, to see if there was any difference in babies' pain levels. Pain levels were assessed using a visual pain scale and whether or not the baby cried.
The Canadian researchers found that pain was reduced when the pneumococcal-conjugate vaccine (PCV) was given after the diphtheria, polio, tetanus, pertussis and Haemophilus-influenzae type b (DPTaP-Hib) vaccine.
Learn more about childhood vaccines from the U.S. Food and Drug Administration.
SOURCES: Mark Diamond, M.D., pediatrician, Children's Hospital of Pittsburgh, Pa.; Peter Belamarich, M.D., pediatrician, Children's Hospital of Montefiore, New York City; May 2009, Archives of Pediatric & Adolescent Medicine