Pneumococcal vaccine could aid pandemic preparedness

US plans for an influenza virus pandemic should include a strong recommendation for bacterial pneumonia vaccination, as this measure has been shown to reduce influenza mortality by up to 50%.

In the US pandemic plan, there is little mention of bacterial vaccines. We believe their role is significant and has not been considered up until now.

Although the influenza virus alone can be fatal, the risk of death is greater with secondary pneumococcal infection, said by a professor of infectious diseases and the William H. Foege Chair of Global Health at Emory University, Atlanta.

The combination of bacterial superinfection and influenza is highly fatal. It’s a huge problem, and it’s not a small part of influenza mortality and morbidity.

Evidence that pneumococcal infection played a major role in the 1918 influenza pandemic is substantial but seems to have been forgotten, doctor recently wrote in a letter to the editor, citing historical evidence of culturable pneumococci in the blood of at least half of the survivors and victims of influenza.

A randomized, controlled trial has shown that, in children, vaccination against the pneumococcal bacteria results in a 31% decrease in pneumonias associated with respiratory viruses. Because of the vaccine, they are not getting the superinfection that brings them to the hospital. People have known for years that there can be bacterial superinfections with influenza, but they just didn’t realize how common they were.

The 23-valent pneumococcal polysaccharide vaccine (PPV 23) is recommended in adults older than 65 years, but giving the 7-valent pneumococcal conjugate vaccine (PCV 7) to children is more protective against bacterial pneumonia in adults.

Data from the Centers for Disease Control and Prevention show that adult infections with the 7 pneumococcal strains covered in the children’s vaccine have decreased, while infections from the other 16 strains covered by the adult vaccine have increased. The burden of disease in adults has been impacted more by giving the conjugate vaccine to children than by giving the 23-valent vaccine to adults.

This had led some investigators to ask whether adults might benefit by being immunized using the children’s conjugate vaccine.

A new study has shown that vaccinating children protects adults against all (not just bacteremic) pneumococcal pneumonia.