American Board of Internal Medicine (ABIM) Certification Practice Exam

What immunization should all adults, including immunocompromised patients, receive once?

1. The influenza vaccine

2. The tetanus-diphtheria-acellular pertussis vaccine

3. The varicella vaccine

4. The hepatitis B vaccine

The correct answer is: The tetanus-diphtheria-acellular pertussis vaccine

The tetanus-diphtheria-acellular pertussis (Tdap) vaccine is recommended for all adults, including those who are immunocompromised, as it provides vital protection against serious diseases. This vaccine is particularly crucial because pertussis (whooping cough) can have severe consequences for individuals with weakened immune systems, as well as for young infants who may be vulnerable to severe illness if exposed to pertussis. The recommendation to administer the Tdap vaccine once to adults is in line with guidelines, which suggest that adults should receive this vaccine if they have not previously received it as an adolescent or adult. Additionally, subsequent boosters of the tetanus-diphtheria (Td) component are recommended every 10 years, but the initial Tdap dose is critical for establishing immunity against pertussis. In contrast, other vaccines listed may not be recommended universally for all adults or immunocompromised individuals in the same way. For example, while the influenza vaccine is recommended annually for all adults, the emphasis on a single Tdap dose distinguishes it due to its role in controlling pertussis outbreaks, especially in vulnerable populations. Similarly, the varicella vaccine is often less relevant for adults who have already had chickenpox or for certain