Pneumococcal vaccine does not appear to protect against pneumonia

January 5, 2009

Commonly used pneumococcal polysaccharide vaccines do not appear to be effective for preventing pneumonia, found a study by a team of researchers from Switzerland and the United Kingdom.

In many industrialized countries, polysaccharide pneumococcal vaccines (PPVs) are currently recommended to help prevent pneumococcal disease in people aged 65 and over and for younger people with increased risk due to conditions like HIV. Studies have shown conflicting results regarding the efficacy of PPV.

The study, a systematic review and meta-analysis, looked at 22 clinical trials, reviews and meta-analyses and more than 100,000 participants from countries in North America as well as India, Africa, Latin America and the Caribbean. Unlike other similar studies the authors examined the reasons why different clinical trials produced different results. They found that the quality of the studies substantially affected the results. When only high quality trials were included, there was no evidence that PPVs could prevent pneumonia. The study adds to the ongoing debate around effectiveness of the vaccine.

"Policy makers may therefore wish to reconsider their current recommendations for PPV, especially where routine pneumococcal conjugate immunization has been introduced," conclude Dr. Matthias Egger from the University of Bern, Switzerland and coauthors.

However, in a related commentary www.cmaj.ca/press/pg18.pdf>, Dr. Ross Andrews and coauthor from the Menzies School of Health Research, Darwin, Australia state that the researchers' conclusions exceed the evidence presented. They caution that there should be no change in vaccine policy in countries that recommend PPV to prevent invasive pneumococcal disease.

Paper: www.cmaj.ca/press/pg48.pdf>

Source: Canadian Medical Association Journal

Explore further: Community of soil bacteria saves wild tobacco plants from root rot

Related Stories

Some vaccines support evolution of more-virulent viruses

July 27, 2015

Scientific experiments with the herpesvirus such as the one that causes Marek's disease in poultry have confirmed, for the first time, the highly controversial theory that some vaccines could allow more-virulent versions ...

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

(PhysOrg.com) -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.