IgG Antibody to Streptococcus pneumoniae (Serum)

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have a history of pneumococcal infections, are at high risk for pneumonia (e.g., due to age, chronic illness, or weakened immune system), or if you’ve received pneumococcal vaccination to monitor your immune response.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm to draw blood. The process usually takes a few minutes, and you may feel a brief pinch. If you’re nervous, let your provider know—some people use numbing cream or distractions.

What the Results Mean

Higher-than-normal levels may indicate your body is producing antibodies in response to infection or vaccination. Lower-than-normal levels could suggest an impaired immune response, especially if you’ve had recent exposure to pneumococcal bacteria.

Common Reasons for Testing

This test is often used in high-risk patients (e.g., children with sickle cell disease, elderly adults, or those with HIV) to track pneumococcal immunity or diagnose suspected infections.