The nation's toddlers are being immunized at or near Healthy People 2010 goals of 90 percent for longer-standing recommended vaccines, according to the results of the 2009 National Immunization Survey. However, one top CDC official says that sporadic disease outbreaks in some areas that are associated with lower rates of coverage for certain vaccines confirm the importance of working with parents to ensure they have their children immunized appropriately.
The survey, published Sept. 17 in Morbidity and Mortality Weekly Report(www.cdc.gov), reported immunization results for more than 17,000 children born between January 2006 and July 2008.
Assistant Surgeon General Anne Schuchat, M.D., director of the CDC's National Center for Immunization and Respiratory Diseases, called the report "reassuring" during a Sept. 16 news conference(cdc.gov), noting that it indicated that less than 1 percent of children ages 19-35 months had received none of the vaccines recommended(5 page PDF) for that age group.
"Today's report is generally very reassuring, despite concerns we have seen in the past about whether parents are continuing to have their children vaccinated and despite some resurgence in vaccine-prevented diseases in particular areas," Schuchat said.
According to the survey, coverage for poliovirus (92.8 percent); measles, mumps, and rubella, or MMR, (90 percent); hepatitis B (92.4 percent); and varicella (89.6) vaccines remained at or near the 90 percent goals established by HHS' Healthy People 2010 initiative for each of these vaccines.
It's worth noting, however, that coverage with at least one dose of MMR vaccine has dipped slightly, from 92.3 percent in the 2007 survey to 90 percent in the 2009 report. Coincidentally, a 2008 outbreak of measles affected more than 100 patients in more than a dozen states.
Schuchat said that although the overall national rate remains high, children remain more susceptible to the disease in communities with lower rates.
"I think this shows that every year, parents need to remain vigilant," she said. "We need providers to keep doing the great jobs of educating parents about vaccines, answering their questions and making sure they are able to protect their kids."
Declining childhood immunization rates coincided with another disease outbreak -- this one, of pertussis -- but Schuchat said the large spike in whooping cough cases this year in California might have more to do with adolescent and adult vaccination rates.
Schuchat said although it is important for infants and toddlers to receive diphtheria, tetanus, and pertussis, or DTaP, vaccine, the principle challenge is ongoing pertussis transmission in teens, adults and infants younger than age 2 months, who cannot yet receive the vaccine.
Shuchat said it was important that adults, especially those who spend time with young infants, the older siblings of infants and health care workers receive tetanus, diphtheria and pertussis, or Tdap, vaccine in order to stop transmission of the disease.
Among children ages 19-35 months, coverage with three doses of DTaP fell slightly from 96.2 percent in 2008 to 95 percent in 2009, while coverage with four doses fell from 84.6 percent to 83.9 percent.
As of Sept. 14, California had more than 4,000 reported cases of pertussis(www.cdph.ca.gov), and nine infant deaths had been linked to the outbreak.
Schuchat said California's DTaP coverage rate for children ages 19-35 months was 83.4 percent.
Yet another dip in vaccine coverage rates also coincided with an outbreak during the reporting period, but the decline of Haemophilus influenzae type b, or Hib, immunizations was related, at least in part, to a vaccine shortage that lasted from December 2007 to September 2009.
Coverage with three Hib doses fell from 92.9 percent in 2007 to 83.6 percent in 2009. The CDC's Advisory Committee on Immunization Practices, or ACIP, the AAFP and the American Academy of Pediatrics recommended deferring the booster dose in most healthy children to maintain an Hib vaccine supply sufficient to enable younger children to complete the primary series.
Despite the shortage, 92.1 percent of eligible children completed the primary Hib series during the reporting period.
Meanwhile, coverage rates for both the birth dose of hepatitis B vaccine (60.8 percent) and two doses of hepatitis A vaccine (46.6 percent) increased by more than 5 percent.
Live rotavirus vaccine, which was licensed in 2006, was included in the survey for the first time, and 43.9 percent of children had received the vaccine. Schuchat said that among children born between January and June 2008, coverage was 60 percent.
According to the MMWR article, hospitalizations for gastroenteritis during the rotavirus season have declined significantly since the introduction of the live vaccine, as have emergency department visits and physician office visits.