SEATTLE, April 30 (UPI) -- The pneumonia vaccine, which is recommended for all people over the age of 65, does not prevent the most common form of the illness in the elderly, a study released Wednesday reveals.
The large study, involving more than 47,000 senior citizens, found the vaccine "did not appear to prevent pneumonia overall," Dr. Lisa Jackson, the principal investigator of the study and an associate investigator at Group Health Cooperative's Center for Health Studies, told United Press International.
However, seniors should continue to receive the vaccine -- referred to as the pneumococcal vaccine -- because it was effective in preventing bacteremia, a rarer but deadlier form of infection caused by the same bacteria that causes pneumonia, Jackson said.
Other disease experts agreed with that recommendation.
"We're still gung-ho for use of this vaccine in people age 65 or older because it clearly is effective in preventing (bacteremia)," Dr. William Schaffner told UPI. Schaffner is chairman of Vanderbilt University's Department of Preventive Medicine at Vanderbilt University Medical Center in Nashville and a member of the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices.
Infection with the bacteria Streptococcus pneumoniae can affect the lungs and cause pneumonia, but it can also circulate in the bloodstream and cause bacteremia. The bloodstream infection is uncommon, but it is fatal in about 20 percent of cases.
Pneumonia also can be a serious problem in the elderly, requiring more than 600,000 seniors to be hospitalized each year. There are multiple causes of pneumonia and the Streptococcus bacteria may account for up to half of those hospitalizations but it was unclear whether the vaccine prevented this infection.
In the study, which appears in the May 1 issue of The New England Journal of Medicine, Jackson's team monitored 47,365 adults ages 65 or older for hospitalization for pneumonia over a 3-year period.
Those who had received the pneumococcal vaccine did not have a lower risk of developing pneumonia or being hospitalized for the illness as compared to those who were not vaccinated. Actually, those who were vaccinated had a slightly higher risk for hospitalization due to pneumonia.
However, the vaccine was associated with a significant reduction in the risk of developing bacteremia.
The findings suggest "we need to develop other types of vaccines if we want to make an impact on (pneumonia) in seniors," Jackson said, noting that the elderly, particularly those with chronic heart problems or other health conditions, are most at risk of developing serious complications from pneumonia.
Research is being done to find vaccines that are better at preventing pneumonia, but in the meantime, seniors can lower their risk by ensuring they receive the influenza vaccine every year, she said.
The flu can increase a senior's risk of developing pneumonia and studies have shown "that seniors who get the influenza vaccine have a lower risk of pneumonia during the flu season," Jackson said.
Schaffner agreed with that recommendation. "Two things are terribly important" for seniors, he said. "Get the pneumococcal vaccine and get the annual flu shot because the flu predisposes to all kinds of pneumonia."
One vaccine in development that may prove more effective at preventing pneumonia in seniors is something called the surface protein vaccine, Schaffner said. That is still being studied but "most of us think that has a better chance of being more effective in adults," he said.
Reported by Steve Mitchell, UPI Medical Correspondent, in Washington.
