Public health experts say they're concerned about the low number of U.S. adults who receive recommended vaccinations -- and in particular about seniors who aren't immunized against pneumonia.
As of 2008, one-third of people 65 and older had not received the pneumococcal vaccine, according to a report issued by the Trust for America's Health (TFAH), the Infectious Diseases Society of America (IDSA), and the Robert Wood Johnson Foundation.
In 36 states, 30 percent or more of their older residents had not received the vaccine.
The worst coverage was in the District of Columbia, where 45.6 percent of seniors had not been vaccinated. Even in the best performing state, Oregon, more than a quarter (26.8 percent) of older people had not received the one-time shot.
Among all adults, the investigators also found extremely low rates of immunization against tetanus, diphtheria, and pertussis (2.1 percent), shingles (less than 2 percent), human papillomavirus (10 percent), and seasonal influenza (36.1 percent).
"The vaccination efforts around the 2009 H1N1 outbreak actually showed how well our public health system can react to vaccinate millions of people in a very short amount of time," L.J. Tan, director of medicine and public health for the American Medical Association, told reporters in a conference call.
"But I think our response also clearly demonstrated that we do have a lack of a strategy and a system for vaccinating adults."
Jeffrey Levi, executive director of TFAH, said, "We need a national strategy to make vaccines a regular part of medical care and to educate Americans about the effectiveness and safety of vaccines."
Doing so could avoid 40,000 to 50,000 deaths from vaccine-preventable illnesses and save about $10 billion in healthcare costs each year, he said.
But, according to Dr. William Schaffner, chair of IDSA's immunization working group and a co-author of the report, there are many obstacles to adult vaccination efforts.
First, unlike children in school, adults lack widespread institutional access to adults or a way to require most to undergo vaccination.
In addition, there are limited interactions with the healthcare system because, also unlike in children, care in adults generally revolves around acute care and not well care visits.
Insurance coverage also plays a major role in low vaccination rates among adults, and not just in the uninsured or underinsured.
Most insurance plans do not cover routine vaccination, Schaffner said, a situation that would change under pending healthcare reform legislation in Congress. That would require insurers to pay for all vaccinations recommended by the CDC's Advisory Committee on Immunization Practices.
Schaffner also cited what he called misunderstandings and misinformation regarding the safety and effectiveness of vaccines, and the limited support for research, development, and production of vaccines as reasons for low immunization rates among adults.
"It's a shame that we aren't focusing enough resources on the science to prevent disease and we don't have a system where we can better protect people by getting them all of the vaccines that are currently available," he said.