Which combination of antibody tests may indicate recent vaccination or early primary infection for rubella?

Which combination of antibody tests may indicate recent vaccination or early primary infection for rubella?

• A. Only IgG antibodies positive
• B. Only IgM antibodies positive
• C. Both IgG and IgM antibodies positive
• D. Fourfold rise in titer for IgG antibodies

Answer: (B)

The presence of only IgM antibodies is indicative of a recent infection or current vaccination against rubella. IgM is the first type of antibody produced by the immune system in response to an infection; it appears soon after exposure to a pathogen. In the context of vaccination or primary infection, the detection of IgM antibodies suggests that the immune response is still in its early stages. This timing is critical for distinguishing between a recent acute infection and a more established immune response, which is typically indicated by the presence of IgG antibodies. When only IgG antibodies are positive, it could indicate past infection or vaccination but does not specifically point to a recent infection or vaccination event. In contrast, a fourfold rise in titer for IgG antibodies might suggest a recent infection but is not indicative of a prompt immune response like the presence of IgM. Therefore, in cases of recent vaccination or early primary infection, the detection of only IgM provides the clearest indication of a current response from the immune system to the rubella virus.

The presence of only IgM antibodies is indicative of a recent infection or current vaccination against rubella. IgM is the first type of antibody produced by the immune system in response to an infection; it appears soon after exposure to a pathogen.

In the context of vaccination or primary infection, the detection of IgM antibodies suggests that the immune response is still in its early stages. This timing is critical for distinguishing between a recent acute infection and a more established immune response, which is typically indicated by the presence of IgG antibodies.

When only IgG antibodies are positive, it could indicate past infection or vaccination but does not specifically point to a recent infection or vaccination event. In contrast, a fourfold rise in titer for IgG antibodies might suggest a recent infection but is not indicative of a prompt immune response like the presence of IgM. Therefore, in cases of recent vaccination or early primary infection, the detection of only IgM provides the clearest indication of a current response from the immune system to the rubella virus.