American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the preferred postexposure prevention method for varicella infection in patients who can receive varicella vaccination?

1. Passive immunoprophylaxis with varicella-zoster immune globulin

2. Administration of the varicella vaccine

3. Use of antiviral medications

4. Observation without treatment

The correct answer is: Administration of the varicella vaccine

The preferred postexposure prevention method for varicella infection in patients who can receive varicella vaccination is administration of the varicella vaccine. This approach is effective because if the vaccine is given within three to five days after exposure to the varicella virus, it can significantly reduce the risk of developing the disease or attenuate its severity. The varicella vaccine is a live attenuated vaccine that stimulates the immune system to produce a response similar to that of a natural infection, which helps in preventing the actual disease. This proactive approach is usually recommended for susceptible individuals who have had close contact with someone with varicella or shingles, provided they are not immunocompromised or have contraindications to vaccination. Passive immunoprophylaxis with varicella-zoster immune globulin is generally reserved for high-risk individuals, such as pregnant women or those with severely weakened immune systems who cannot receive the vaccine. Antiviral medications might be utilized in cases of high-risk patients who develop varicella, but they are not a primary method for postexposure prevention. Observation without treatment would not effectively prevent the disease after exposure, thus making vaccination the optimal strategy in appropriate candidates.