What are specific hemagglutination inhibition (H1) titers?
A It’s difficult to find a list defining SIV H1 titers. Many answers are based on experimental infections or field experiences measuring natural infections. Laboratories often use a titer of > 1:40 as evidence of a specific SIV H1 titer. But, that doesn’t mean that a titer of 1:10 or 1:20 is not specific. They may simply represent low-antibody titers in a population facing early infection or with declining antibody levels.
