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Disease information 

Virus or bacteria

Pneumococcus is caused by Streptococcus pneumoniae. This bacterium is commonly found lining the nose and the back of the throat.

How it spreads

• Coughing
• Sneezing
• Talking

Pneumococcal bacteria sometimes live in the back of the throat. Occasionally, they are able to get into the blood as a result of damage to the cells in the throat. This damage can be caused by illness, smoking or drinking. When the bacteria get into the bloodstream, the person is said to have “invasive pneumococcal disease.”

Symptoms

Symptoms vary based on the complications that occur.

Typical disease timeline

The length of illness for this disease varies, depending on a number of factors. One factor is which complications occur. The image shows the chance of experiencing each type of complication if the bacteria enter the person’s blood, meaning if they develop invasive disease.

Possible complications

• Lung Infections
  • Pneumonia (5 of 100 people will die from this complication)
  • Empyema
  • Lung abscesses
• Meningitis (30 of 100 people will die from this complication)
• Sepsis (20 of 100 people will die from this complication)
• Other
  • Septic arthritis
  • Pericarditis
  • Otitis media 

Other things to know

• S. pneumoniae is called an "opportunistic" bacterium. This is because it causes disease when an opportunity presents itself for the bacteria to get into the blood. This can happen when an infection like influenza damages cells in the respiratory tract. The pneumococcal infection that occurs after an influenza infection is why many elderly people become sick with or die from pneumonia each year.
• Interest in developing a vaccine for pneumococcus waned with the discovery of antibiotics. But, antibiotic resistant strains of pneumococcus began to appear. Because of this, developing a vaccine became important for combating this disease.
• Pneumococcal bacteria only infect people.
• Before the vaccine: Each year in the U.S., pneumococcus caused about 700 cases of meningitis, 17,000 cases of sepsis and 71,000 cases of pneumonia.

Vaccine information 

The pneumococcal vaccine is used to prevent pneumococcus.

Two types of pneumococcal vaccines are available: 

• Polysaccharide vaccine (PPSV) — This type contains the sugar coating from the bacteria. 
• Conjugate vaccine (PCV) — This type also contains the sugar coating (polysaccharide), but in this version of vaccine, the polysaccharide is linked to a harmless, “helper” protein in order to produce a stronger immune response. 

Four pneumococcal vaccines are available:

• PCV15, PCV20 and PCV21 — These versions protect against 15, 20 or 21 types of pneumococcus, respectively. Each of these versions are conjugate vaccines, meaning they include the harmless, “helper” protein. These versions are used in babies and adults. 
• PPSV23 — This version is a polysaccharide vaccine. It protects against 23 common types of pneumococcus. This version is most commonly used for older adults and people at increased risk of infection who received a version of PCV with less than 20 types of pneumococcus. People with chronic conditions of the heart or lungs, among others, are at higher risk for pneumococcal infection.

Vaccine type

• Polysaccharide vaccines

Vaccine side effects

Common

• Pain and swelling at the injection site (5 to 50 of 100 recipients)
• Fever (greater than 100.4°F) (Up to 35 of 100 recipients)
• High fever (greater than 102°F) (Up to 10 of 100 recipients)
• Decreased appetite (80 of 100 recipients)
• Irritability (80 of 100 recipients)
• Headache (5 of 100 recipients of PCV21)
• Muscle aches (2 of 100 recipients of PCV21)

Rare

• None

Very rare

• Serious allergic reaction (fewer than 1 of 1,000,000 recipients)

Other things to know 

Pneumococcus can be fatal. It is particularly dangerous for older people, whose immune systems can not readily recover from pneumonia, and young infants, whose immune systems do not make a good response to polysaccharides and whose breathing tubes are small, making it difficult to breathe when damaged by or clogged during infection. 

Reasons to get the pneumococcal vaccine

• Pneumococcus causes infections every year in the U.S.
• Pneumococcal infections can complicate other infections.
• Some pneumococcal infections do not respond to antibiotics.
• The pneumococcal vaccine works.
• The pneumococcal vaccine is safe.