Pneumococcal disease

One of the most important vaccinations a senior should get is against pneumococcal disease. What is pneumococcal disease? Streptococcus pneumoniae is a Grampositive bacterium that is known to cause invasive disease such as sepsis, meningitis and pneumonia.

Symptoms depend on the site of infection. It is a major cause of morbidity and mortality in children, the elderly population and individuals with immunosuppression and other chronic conditions.

S. pneumoniae can be spread from an infected person to another person by droplets from the nose or mouth, by sneezing or coughing. It is estimated that about one million children die of pneumococcal disease each year, most of whom are children in developing countries. In developed countries such as Canada, a large burden of disease exists among elderly persons.

Children and adults are often asymptomatically colonized with S. Pneumoniae in their upper respiratory tract and nasopharynx (nose and throat area).

IPD or invasive pneumococcal disease is a severe form of the disease that occurs when the bacterium invades normally sterile sites, such as the blood stream and central nervous system. Chronic conditions predispose to complications of pneumococcal infections and those over 65 years of age are also at increased risk.

Since 2006, implementation of Canadawide vaccinations programs has resulted in a decreased incidence rate of pneumococcal disease in the under-5 age group but there has been a steady increase in the incidence rate in adults 60 years and older.

Two forms of pneumococcal vaccine are available in Canada; polysaccharide vaccines and conjugated vaccines which have polysaccharide antigens bound to a protein.

The polysaccharide vaccines such as the well-known Pneumovax 23 are sugar based and do not result in as strong an immune response as the conjugate vaccines. They have poor effectiveness against non-bacteremic pneumonia, and also have a limited duration of efficacy which means people at risk need to be revaccinated after five years.

Prevnar 13 is a conjugate vaccine. This creates a better, robust, immune response in the recipient, whether young or old.

Another advantage is that it provides an immune response even in immunocompromised people. The disadvantage of this vaccination is that it only provides protection against 13 serotypes of Strep pneumoniae. Prevnar 13 shares 12 of these with Pneumovax 23 but also has an antigen of serotype 6A unique to it.

The National Advisory Committee on Immunisation (NACI) recommends the following:

In the elderly who have never been immunized against pneumococcal disease Prevnar13 should be given first, followed by Pneumovax 23 at least 8 weeks later (not sooner than this!).

Elderly people who have had Pneumovax 23 within the last 3 years should receive Prevnar 13 only but at least one year after the Pneumovax.

In people with underlying conditions such as COPD, heart disease or diabetes, who have already had their Pneumovax 23 and are due for their five year revaccination dose, this is a good time to give them Prevnar 13, followed by an eight week break, then their booster of Pneumovax23.

An ideal time to discuss your particular needs with your family doctor is when you are getting your annual flu shot (you are getting your annual flu shot, aren't you??).

Next week: Should I get the “Shingles shot”?

Dr. Wendy Ross is the lead physician at the Penticton cancer clinic and The Herald’s health columnist. Email: drwendyross@gmail.com, and on the Web: drwendyross.com. This column appears Tuesdays .