What is PPV?

PPV is the abbreviated name of the Pneumococcal Polysaccharide Vaccine, an injection administered to immunise people against pneumococcal infections. In this article we look at what pneumococcal infections are and why vaccinating against them is so important.

What does the PPV injection do?

As mentioned above, the PPV injection immunises against pneumococcal infections. These are diseases caused by an extremely potent bacterium called Streptococcus pneumonia, but usually shortened to pneumococcus. A pneumococcal infection is a disease caused by any one of the over 90 different strains of pneumococcus, each of which can have a unique mechanism of action and cause a variety of different serious bacterial infections. The most well-known pneumococcal infection is probably pneumonia, an infection of the respiratory system which can be fatal amongst vulnerable populations like infants and the elderly. However pneumococcus can also cause:


  • An inflammation of the sinuses referred to as sinusitis.
  • An inflammation of the meninges (protective coating of the brain) which causes a range of unpleasant symptoms and can be deadly.
  • Whole body inflammation called sepsis which is also referred to as blood poisoning.
  • An infection of the blood called bacteraemia, where pneumococcal bacteria make their way into the bloodstream as a complication of a serious infection.

The bacteria can also be held responsible for other infections affecting various other organs. This s why immunising against pneumococcus is important, particularly amongst at-risk groups vulnerable to infections from the bacterium. 

PPV is actually one of two widely used pneumococcal vaccines, the second being PCV, the pneumococcal conjugate vaccine.

Who receives the PPV injection?

PPV is given to a slightly different population than its counterpart, PCV. PPV is used on elderly people aged 65 and above, while PCV is the injection administered to young children.

The elderly are typically at risk of serious pneumococcal infection because of the fact that our immunity diminishes as we get older. This puts us at more serious risk of developing complications, and many elderly people are likely to develop pneumonia as a complication of a mild infection like the flu.

What kind of vaccine is PPV?

PPV is a polysaccharide vaccine, the latest incarnation of which is the drug commercially dubbed Pneumovax 23. Polysaccharide vaccines make use of specific components derived from the coating of pneumococcal bacteria. Pneumococcus belongs to a class of bacteria referred to as gram-positive because of their polysaccharide coating. It is this coating which identifies the bacterium as an invader to our body’s defences, and by engineering a vaccine with specific polysaccharide antigens (identifying markers), people of all ages can be safely and effectively immunised against the pneumococcus.

Because of its use of polysaccharide antigens PPV is far safer than alternative vaccination technologies like live vaccines, which make use of weakened strains of living virus to immunise people. PPV can therefore be used on at-risk groups very safely, thereby granting immunisations to a broader range of people.


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VACCINATIONS