A viral serology test detects antibodies in a blood sample to determine whether someone has been infected with a specific virus or has developed immunity after infection or vaccination. It helps confirm recent or past infections, assess immune status, guide clinical decisions and public-health measures, and complement direct viral tests (such as PCR) that detect active infection.

A serology test detects antibodies in blood—primarily IgM (early) and IgG (later)—showing a past or recent immune response from infection or vaccination. It does not reliably diagnose active infection (use PCR) and antibody presence doesn’t always confirm protective immunity. Timing, test sensitivity/specificity and possible false positives/negatives affect results. Serology is most useful for surveillance and assessing prior exposure.

A viral screening blood test checks your blood for virus-specific markers—antigens, antibodies, or viral genetic material—to identify current or past infections. Tests may use antibody/antigen assays or molecular techniques (PCR) to detect viruses such as HIV, hepatitis B/C, and others. Results guide diagnosis, treatment, monitoring, or blood-donor safety; abnormal or positive screens usually require confirmatory testing and clinical follow-up.

Serology treatment uses blood serum antibodies—from recovered donors or manufactured immunoglobulins—to provide passive immunity or modify immune responses. Examples include convalescent plasma, pooled immunoglobulin, and monoclonal antibodies for infections or immune disorders. Benefits can be immediate but temporary; effectiveness depends on timing and antibody levels. Risks include allergic or transfusion reactions and variable clinical outcomes.

Serology (antibody) test costs vary by country, lab and type. In many public health systems it's free; private labs typically charge roughly $20–$150 (or local equivalent). In countries like India private prices often range about ₹400–₹2,000. Prices depend on test complexity, lab accreditation and whether insurance or government programs cover it. Always confirm cost with the testing provider.

Polymerase chain reaction (PCR), specifically reverse-transcription PCR (RT-PCR) for RNA viruses, is the most sensitive test to detect active viral infection by identifying viral genetic material. Rapid antigen tests can also detect active infection by identifying viral proteins but are less sensitive. Antibody (serology) tests indicate past exposure and generally do not confirm current infection.