A 19-year-old man presents to his primary care physician. He is asymptomatic and has no acute complaints, has no medical problems, and takes no medications. He was born in the United States but moved to El Salvador at age 11 and has only recently moved back to the United States in the past year. He was up to date on his vaccinations prior to his move to El Salvador. He last received a diphtheria, tetanus, and acellular pertussis (DTaP) vaccine 14 years ago at age 5, the second dose of a meningococcal vaccine 3 years ago, and an influenza vaccine 2 months ago. The patient’s temperature is 98.2°F (36.8°C), blood pressure is 120/76 mmHg, pulse is 82/min, and respirations are 16/min. There are no rashes noted on physical exam. Which of the following vaccine regimens is indicated in this patient?
Tetanus, diphtheria, acellular pertussis, and influenza
Tetanus and diphtheria
Influenza
Tetanus, diphtheria, and acellular pertussis
Tetanus, diphtheria, and acellular pertussis
This patient has recently moved back to the United States after living in another country for several years and is behind on his tetanus, diphtheria, and pertussis vaccine series. The tetanus, diphtheria, and acellular pertussis (Tdap) vaccine is indicated at least once in adults who have not previously received Tdap.

The standard vaccination schedule for tetanus, diphtheria, and pertussis includes a 5-dose childhood vaccine series consisting of DTaP at ages 2 months, 4 months, 6 months, 15-18 months, and 4-6 years. The first booster dose then consists of Tdap at age 11-12, with a tetanus and diphtheria (Td) vaccine every 10 years afterwards. In adults who have not previously received Tdap, a single Tdap dose should be administered regardless of time interval since the last dose of Td. Subsequent Td booster doses should then be given at 10-year intervals. Contraindications to Tdap include prior anaphylaxis after a tetanus, diphtheria, or pertussis vaccine or a history of seizures or encephalopathy within 7 days of receiving a previous pertussis-containing vaccine.

Kerr et al. studied the risk of major birth defects after administering the Tdap vaccine in pregnant patients. The authors found no increase in the risk of malformations in the offspring of pregnant patients that received the Tdap vaccine. The authors recommend the administration of Tdap during pregnancy.

Incorrect Answers:
Answer A: Influenza is incorrect because the influenza vaccine is recommended only once per flu season. This patient already received the flu vaccine during this flu season, so the influenza vaccine is not indicated.

Answer B: Tetanus and diphtheria only are incorrect because the Td vaccine booster is indicated every 10 years in adults who have already received a prior dose of Tdap. In adults who have never received a previous Tdap dose, Tdap is indicated unless contraindications exist.

Answer C: Tetanus, diphtheria, acellular pertussis, and influenza are incorrect because influenza vaccine is not indicated in this patient. This patient has already received a dose of the influenza vaccine during this flu season.

Answer E: Tetanus, diphtheria, and influenza are incorrect because neither the Td nor influenza vaccines are indicated in this patient. The Td vaccine is indicated every 10 years in adults who have already received a prior dose of Tdap. The influenza vaccine is only indicated once per flu season.

Bullet Summary:
The tetanus, diphtheria, and acellular pertussis (Tdap) vaccine is usually administered to adolescents at age 11-12 and is indicated at least once in adults who have not previously received Tdap.