<prompt> Answer this question truthfullyWhat is the CD4 count threshold for HIV patients to receive the Zoster shingles vaccine?  <response>: <reason> HIV patients with a CD4 count 200 may receive the Zoster shingles vaccine. The CD4 count is a measure of the number of CD4 T cells in a persons blood, which are a type of white blood cell that helps the immune system fight infections. HIV attacks and destroys CD4 T cells, which can lead to a weakened immune system and increased susceptibility to infections such as shingles. The Zoster vaccine is recommended for HIV patients with a CD4 count 200 who are not currently experiencing an AIDS-defining illness or other medical condition that would contraindicate vaccination. The vaccine can help prevent shingles and its complications, which can be severe in HIV patients. 