Respiratory Syncytial Virus Antibody, Serum (Qualitative)

What Does This Test Measure?

The test looks for specific antibodies (immunoglobulin G, or IgG) that your immune system produces after exposure to RSV. These antibodies are a sign your body has recognized and fought off the virus, either from a past infection or vaccination. This is a qualitative test, meaning it only tells you whether antibodies are present or not, not their exact amount.

Why Might You Need This Test?

Doctors may order this test if you have symptoms of respiratory infections (like cold-like or flu-like symptoms with coughing, wheezing, or difficulty breathing), especially if you’re in a high-risk group (e.g., infants, elderly adults, or those with weakened immune systems). It can also be used to monitor immunity in people who’ve had RSV before or received RSV vaccines.

What Does a Positive Result Mean?

A positive result means your blood contains RSV antibodies, suggesting you’ve likely had an RSV infection in the past or have some level of immunity. This doesn’t mean you’re currently infected but could indicate protection against future infections.

What Does a Negative Result Mean?

A negative result means your blood does not currently have detectable RSV antibodies. This doesn’t rule out past infection—some people may not develop detectable antibodies after exposure. It also doesn’t confirm you’re not currently infected; other tests may be needed for that.