Childhood vaccination rates remain high, the CDC says

U.S. immunization rates for the most common childhood vaccines continue to remain near or above the target level of 90% coverage, the Centers for Disease Control and Prevention said Thursday. Rates for the newest vaccines, including hepatitis A, hepatitis B and rotavirus, also continue to grow, the agency reported in its Morbidity and Mortality Weekly Report. Less than 1% of children had not received any vaccines.

“Today’s report is generally very reassuring, despite reports we have seen” about parents being reluctant to immunize children because of fears of a link between vaccines and autism. “We know that parents have a lot of questions, but a number of studies have been done and that question has been resolved. There is no link.” More information about that issue is available here.

The two major exceptions to the trend of increases involve the measles vaccine and that for Haemophilus influenzae b (Hib), which causes meningitis. The latter problem was caused by a shortage of the vaccine during 2008 and 2009 that led the CDC to recommend that physicians not give a fourth (booster) dose of the vaccine to children until the supply problem was resolved. That shortage has been eliminated and vaccination rates are returning to normal, Schuchat said.

For measles, there was “a significant drop, but not a large drop,” from 92.1% in 2008 to 90% in 2009. “It might be a warning sign of large drops to come, or small changes that proved statistically significant,” she said. But it is important to maintain high coverage “because measles is such an infectious disease -- so that when imported cases come in, they don’t find places to spread.” During the last measles outbreak in 1989-91, there were 55,000 hospitalizations, she noted.

The new findings came from the 2009 National Immunization Survey, which conducted telephone interviews with households containing 17,313 children and collected pediatricians’ records on their vaccination history.

Among the findings:

-- Coverage for the hepatitis A vaccine increased from 40.4% in 2008 to 46.6% in 2009.

-- Coverage for the hepatitis B vaccine given at birth increased from 55.3% to 60.8%.

-- Coverage for the rotavirus vaccine, which was introduced in 2006, had grown to 43.9% in 2009. If the researchers considered only children born between January and June 2008, 60% had been vaccinated.

Schuchat briefly addressed the pertussis (whooping cough) outbreak in California, which has so far killed nine infants. “We don’t think it is the coverage level in babies and toddlers that is the problem,” but the lack of vaccination in adults and teens. “Anybody who is going to be around a baby” needs to get a booster shot of the TDaP vaccine, which protects against pertussis. “A new mother can get it right there in the hospital, as well as the father and other caretakers,” she said. Adults and teens can also get it from physicians and many pharmacies. “We want to provide a cocoon of protection around the newborn” until he or she is old enough to receive a vaccination of their own.

There has been debate about whether a woman should get the pertussis booster during pregnancy, she said. Researchers have found no evidence that it is harmful, she noted, but the current recommendation is that the mother receive the vaccine before getting pregnant or immediately after giving birth.

-- Thomas H. Maugh II / Los Angeles Times