The U.S. Centers for Disease Control and Prevention says more American teens are receiving vaccines that protect against diseases such as pertussis, meningitis and cervical cancer.

A national survey of 20,399 adolescents aged 13 to 17 found that 56 percent had received one dose of tetanus-diphtheria-acellular pertussis vaccine (Tdap) in 2009, up about 15 percentage points from 2008.

"We can see that more parents of adolescents are electing to protect their children from serious diseases such as pertussis (whooping cough), meningitis, and cervical cancer but there is clear room for improvement in our system's ability to reach this age group," said Dr. Anne Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases.

Schuchat noted that with recent outbreaks of whopping cough, teens and adults should make sure to get a one-time Tdap booster to protect infants from catching pertussis.

“Pertussis outbreaks in several states and an increase in pertussis-related infant deaths in California highlight how important it is for pre-teens to receive the Tdap booster,” Schuchat said. “It is important for teens and adults to get a one-time dose of Tdap to protect themselves and those around them from whooping cough. Young infants are most vulnerable to serious complications from pertussis and can be infected by older siblings, parents or other caretakers.”

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.

The survey found that 54 percent of teens got at least one dose of meningococcal conjugate vaccine, up 12 points since 2008.

The survey showed 44 percent of girls had received at least one dose of human papillomavirus, or HPV vaccine, an increase of seven percentage points. Only 27 percent of girls got all three doses of the vaccine, up nine points from 2008.

HPV is the main cause of cervical cancer and also can cause throat, anal and penile cancers.

"Completing the three-dose HPV vaccine series is very important to ensure protection against cervical cancer," Schuchat said. "Visits for immunization can be a great opportunity to address other important preventive issues that all teens need."

Two HPV vaccines are licensed -- Cervarix from GlaxoSmithKline and Gardasil from Merck & Co.

Novartis and Sanofi make vaccines against meningitis and several companies make Tdap vaccines.