Final answer:
For an HIV-positive patient, a CD4 count of ≥ 200 cells/mm³ is sufficient for live vaccines. Counts above this threshold indicate a better capability of the immune system to handle live vaccines. Flow cytometry is used to monitor CD4 counts, and treatment adjustments are made if counts fall below 500 cells/μl.
Step-by-step explanation:
The appropriate CD4 count for an HIV-positive patient receiving live vaccines is ≥ 200 cells/mm³ (option a). It is important that patients with HIV, whose immune systems are compromised, have a sufficient number of CD4 T cells to mount an immune response to the live vaccine without significant risk. A CD4 count of 200 cells/mm³ is generally considered the threshold for administering live vaccines to ensure patient safety and vaccine efficacy. Patients with higher CD4 counts are typically better able to handle live vaccines without increased risk of vaccine-related illness.
As a reference, a healthy person's CD4+T cell count is around 1,000 cells per microliter. A decline to below 400 cells/mm³ may indicate an inability to mount a proper immune response. Flow cytometry is a sensitive test used in hospitals to monitor CD4 T cell counts in HIV-positive patients, with adjustments to treatment being made if the count falls below 500 cells/μl.