Vaccines have been an important part of modern medicine, used as a preventive tool to protect us from disease like polio, tetanus, or small pox. These vaccines work by challenging one’s immune system with an inactive agent similar to the real pathogen. Thus, when faced with the real disease agent our body is able to effectively and efficiently mount an offensive to prevent illness. However a new study is showing that despite vaccines, pneumonia hospital visits still remain quite common. 

Research was published this week in the New England Journal of Medicine and the first study to evaluate pneumonia hospitalization rates since the 1990s, before a vaccine was available for the disease. This prominent disease kills almost 50,000 people in the U.S. Pneumonia rates have declined but older adults are hospitalized for the disease, according to new research from the Centers for Disease Control and Prevention (CDC).

Routine vaccination in children has reduced the rate of pneumonia in adults. The rate of hospitalization for the disease does remain at pre-vaccine levels, about 25 cases per 10,000 adults, according to the CDC study. 

Most disease experts do recommend this study be approached with caution since comparions can't really be made to other studies on pneumonia hospitalization rates in adults since the methods varied so much.

So why does pneumonia hospitalization remain a concern? One main problem is that people aren't proactive in getting the vaccination for pneumonia and influenza, even though the CDC recommends the pneumonia vaccination for all adults ages 65 and older. Only 65% of older adults get it according to the government's National Center for Health Statistics.

The second main issue is the vaccine technically only prevents one kind of bacterial pneumonia in adults, which this study did find less of. But other strains not included in the vaccine may still cause the disease.  The study also found evidence consistent with previous studies that show older adults are most likely to pneumonia hospitalization. Those ages 50-64 are 4x as likely to be hospitalized for the disease as younger adults. 80 years of age and older have 25X the risk. 

One hypothesis for why this occurs is as we age, we're more susceptible to develop underlying conditions that put one at risk for developing pneumonia, some examples being chronic lung disease, heart disease and diabetes. This study analyzed 2,300 adults hospitalized with pneumonia. 

Vaccinations against the flu and pneumonia still remain highly recommended for adults ages 65 and older, young children, and people with specific risk factors.