American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the timing for varicella immunization prior to solid organ transplantation?

1. At the time of transplantation

2. 4 weeks before transplantation

3. 2 weeks before transplantation

4. After the surgery

The correct answer is: 4 weeks before transplantation

The timing for varicella immunization prior to solid organ transplantation is critical to ensure that the recipient has adequate immunity against the varicella virus, reducing the risk of complications that can arise from infection post-transplant. The recommendation to administer the vaccine 4 weeks before transplantation allows for the development of an appropriate immune response, which typically takes about 2 to 4 weeks following vaccination. By immunizing at this interval, the individual has a better chance of building sufficient antibody levels to provide protection against varicella, which can be particularly severe in immunocompromised patients. Administering the vaccine at the time of transplantation or too close to the surgery would not allow adequate time for the immune response to develop, which could leave the patient vulnerable to infection. Vaccinating after the surgery is also not appropriate, as the immunosuppressive therapy initiated after transplantation could hinder the response to the vaccine, rendering it ineffective. Thus, the practice of immunizing 4 weeks before transplantation is deemed optimal for ensuring protection against varicella in solid organ transplant recipients.