A new federal survey released Thursday shows that more American teens have received many of the vaccines they're supposed to receive routinely around ages 11 or 12.
But despite a big improvement for several key vaccines, coverage rates nationally in 2009 remained not much better than 50 percent for booster shots against tetanus and pertussis and a shot aimed at protecting against deadly brain infections.
The Centers for Disease Control and Prevention's national survey of more than 20,000 teens ages 13 to 17 estimates that 56 percent had received one dose of tetanus-diphtheria-acellular pertussis vaccine (Tdap), up about 15 percentage points from 2008.
Coverage for one dose of meningococcal conjugate vaccine rose by 12 percentage points to 54 percent.
The survey also shows that 44 percent of teen girls had received at least one dose of vaccine against the human papillomavirus (HPV), up from 37 percent in 2008. But only about 27 percent had received the recommended three doses of the vaccine, which is intended to prevent cervical cancer from the sexually transmitted virus.
"This year's data are mixed," said Dr. Anne Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases. "We can see that more parents of adolescents are electing to protect their children from serious diseases such as pertussis, meningitis and cervical cancer, but there is clear room for improvement in our system's ability to reach this age group."
Schuchat noted in particular that with several pertussis outbreaks this year, it is important that teens and adults get a one-time Tdap booster to protect any infants they might be around.
Vaccination rates among teens for shots they typically got as infants or preschoolers were considerably higher -- nearly 90 percent for the measles-mumps-rubella series and hepatitis B. But less than half the teens in the survey -- 48.6 percent -- have received the recommended two doses of vaccine against chicken pox.
Teens are particularly hard to reach for vaccines and other preventive care because many don't have a regular doctor or seek care unless they're ill or hurt.