Since Vaccine, Pneumonia Admissions Drop

July 11, 2013

Hospital stays for pneumonia have dropped 10% in the decade since a pneumonia vaccine was introduced, a new study finds. The declines were even sharper among very young children and the elderly. These are the main target groups for the PCV7 vaccine. It protects against 7 strains of pneumococcal bacteria. The vaccine was approved in 2000. Researchers looked at hospital stays for 1997 through 1999. They compared these numbers to rates for 2007 through 2009. Annual hospital stays for pneumonia dropped by 168,000. The drop was steepest, 43%, among children under age 2. Among adults age 85 and older, the decrease was 23%. The pneumococcal vaccine is recommended mainly for babies, people age 65 or older and those with impaired immune systems. Hospital stays for pneumonia also fell for children ages 2 to 4 and for adults of all ages. The rates for children ages 5 through 17 were already low and did not change. The New England Journal of Medicine published the study. MedPage Today wrote about it July 11.

By Robert H. Shmerling, M.D.
Harvard Medical School

What Is the Doctor's Reaction?

When something terrible happens, we take notice. That's true, for example, when a disease causes suffering and death for thousands or even millions of people. Think HIV, epidemics of flu, or Alzheimer's disease.

But when something terrible doesn't happen, it may get much less attention. That tends to be true for successful prevention measures such as vaccines. A new study demonstrates this well. It appears in the latest edition of the New England Journal of Medicine.

The vaccination for a common type of pneumonia is a good example. Soon after the pneumococcal vaccine was developed and approved, it became a routinely recommended vaccine for millions of people. This included infants, the elderly and people with impaired immune systems. The vaccine is also called PCV7, or Pneumovax.

But vaccinations (and other medical treatments) may work better in studies than in "real life." One of the main reasons is that new strains of bacteria may emerge over time. The vaccine might not prevent infection with these newer strains.

Has the pneumonia vaccine delivered on its promise? A new study, sponsored by the Centers for Disease Control and Prevention, suggests that it has.

The vaccine was made to prevent infection with specific strains of pneumococcal bacteria. Within a few years of its introduction, new cases of pneumonia caused by those strains plummeted. This was true for people of all ages.

Infections were reduced even among people who did not get the vaccine. This occurred because of "herd immunity." This means that infections among vaccinated people have dropped so much that the rate of a disease also falls in the population as a whole.

The new study shows that this early success has been maintained. Researchers looked at hospital admission rates for pneumonia and its complications for two periods of time. They compared the late 1990s (before the pneumonia vaccine) with the rates from 2007 to 2009.

The researchers estimated that annual pneumonia-related hospital admissions dropped by:

• 47,000 among children younger than age 2
• 73,000 among adults ages 85 and older
• 168,000 among all age groups

That's a lot of disease prevented! This study does not prove that vaccinations were the only cause of the drop in admissions for pneumonia. But the timing suggests that the pneumonia vaccine deserves a big part of the credit.

What Changes Can I Make Now?

Consider getting the pneumonia vaccine. It is generally recommended for:

• Healthy infants (as a series of shots beginning at age 2 months)
• Any adult age 65 or older
• Adults ages 19 or older with certain long-term medical conditions (such as diabetes and heart failure) and those with poorly functioning immune systems

The specific advice on giving this vaccine has become a bit complicated in recent years. Now there are new versions of the vaccine. The first one was called PCV7 because it covered 7 common strains of pneumococcal bacteria. Newer vaccines covering more strains are called PCV13 and PPSV23.

What type of vaccine should you get? Does it need to be repeated? The answers will depend on your age, medical history and past vaccinations for pneumonia. For example:

If you are at least 65 years old, you should receive a dose of PPSV23.

If you are between the ages of 19 and 64, have HIV infection and have never been vaccinated, you should get the PCV13 vaccine. Then you will need a dose of PPSV23 at least 8 weeks later. Five years after that, you should get a second dose of PPSV23.

If you are 24 years old and smoke or have asthma, you should get the PPSV23 if you have not had a pneumonia vaccination before.

More advice and other specific examples can be found on this government vaccine page.

In case you're wondering, the safety record of the pneumonia vaccine is quite good. So ask your doctor about the pneumonia vaccine. The results of this new study suggest that if your doctor recommends the vaccine, you should probably get it.

What Can I Expect Looking to the Future?

You can expect to hear about even better vaccines in the future. This new study did not address the effect of the newer pneumonia vaccines, PCV13 and PPSV23. Their impact on rates of pneumonia, admissions and death should be the focus of future research.

I hope that future news reports will focus on how to prevent diseases as well as how to treat them. Today's news about the pneumonia vaccination is proof that disease that doesn't happen can be big news.