A federal health panel for the first time has singled out smokers for vaccination because of their high risk of infection from a pneumonia-causing bacterium.
The federal Centers for Disease Control and Prevention already recommends the pneumococcal vaccine for children, adults over 65 and those with chronic illnesses and weakened immune systems.
The panel's new recommendation, proposed Wednesday and expected to be formally adopted by the CDC, would expand the group to smokers ages 19 to 64.
About one-fifth of U.S. adults smoke cigarettes, according to CDC spokesman Curtis Allen. Studies consistently find that smokers account for approximately half of otherwise healthy adults with invasive pneumococcal disease, Allen said.
"The risk of getting pneumococcal pneumonia among smokers is substantially greater than among nonsmokers, so it makes sense to recommend that smokers get the vaccine," said Dr. Norman H. Edelman, chief medical officer for the American Lung Assn. "But that in no way protects you from all of the terrible things that smoking will do."
The CDC committee also recommended that smokers who receive the pneumococcal vaccine be advised to stop smoking. About 50% of regular smokers will die of a smoking-related disease, usually lung cancer, emphysema, chronic bronchitis or cardiovascular disease, Edelman said.
The vaccine protects against several strains of Streptococcus pneumoniae, a group of bacteria also known as pneumococci. They live intermittently in the noses and throats of people of all ages, usually without causing harm.
But in the wrong place, they can cause middle-ear and sinus infections as well as less common but more serious infections of the lungs, central nervous system and blood.
Smoking makes it easier for the bacteria to get to the wrong place by damaging protective mucous membranes and tiny, hair-like cilia in the back of the nose and throat, said Dr. Lisa Jackson, senior investigator for the Seattle-based Group Health Center for Health Studies. Smoking also damages the ability of white blood cells to fight off infections, she said.
The bacterium is the most common cause of pneumonia acquired outside hospitals. It can also infect blood and the lining of the brain, causing meningitis. Studies have shown that the vaccine is effective at preventing those infections, Jackson said.
Pneumococcal blood infections are so severe that 15% to 20% of patients die, even with treatment, said Dr. William Schaffner, an infectious-disease expert at the Vanderbilt Medical Center in Nashville. Treatment is complicated because the bacteria have become resistant to some first-line antibiotics.
"We used to be able to just wave a bottle of penicillin at pneumococci and they would roll over and die," Schaffner said. "Prevention from infection becomes more important when treatment becomes more difficult."
A single dose of pneumococcal vaccine for adults protects against 23 types of Streptococcus pneumoniae.
Also Wednesday, the immunization committee heard reports on the safety of the cervical cancer vaccine Gardasil based on studies conducted since it came on the market in June 2006.
A review of more than 375,000 doses administered over two years did not find increased risk for blood clots, seizures, Guillain-Barre syndrome or other serious medical problems, according to the CDC's Allen.
The vaccine, which the CDC recommends for females between the ages of 11 and 26, protects against four types of human papillomavirus, which causes cervical cancer and is spread through sexual contact.