WBR0608

Author	[[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Yazan Daaboul, M.D. and Alison Leibowitz [1])]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Immunology
Sub Category	SubCategory::General Principles
Prompt	[[Prompt::A young boy is brought by his mother to the physician's office for a scheduled vaccination. The boy has no complaints, and physical examination is unremarkable. Prior to the administration of the vaccine, the mother asks the physician if the vaccine is associated with any serious adverse reactions. The physician explains that the vaccine the child is about to receive is generally safe, but there is a very rare risk of inducing an actual disease. Which of the following vaccines is the child most likely receiving during his check-up?]]
Answer A	AnswerA::Hepatitis A vaccine
Answer A Explanation	AnswerAExp::Hepatitis A vaccine is an inactivated vaccine.
Answer B	AnswerB::Oral polio vaccine
Answer B Explanation	AnswerBExp::Oral polio vaccine (Sabin) is a live attenuated vaccine.
Answer C	AnswerC::Tetanus-diphtheria (Td) vaccine
Answer C Explanation	AnswerCExp::Tetanus-diphtheria (Td) is a toxoid vaccine.
Answer D	AnswerD::Human papillomavirus (HPV)
Answer D Explanation	AnswerDExp::HPV vaccine is a recombinant vaccine.
Answer E	AnswerE::Acellular pertussis
Answer E Explanation	AnswerEExp::Acellular pertussis vaccine is a subunit vaccine.
Right Answer	RightAnswer::B
Explanation	[[Explanation::The patient in this vignette is most likely being administered a live attenuated vaccine. Vaccines may be classified according to the table shown below. Only live attenuated vaccines contain real-life weakened bacterial or viral agents that have a rare potential to revert and induce actual disease. On the other hand, inactivated vaccines, subunit vaccines, and toxoid vaccines either contain killed agents or non-living components of agents and do not revert to cause actual disease. Examples of live attenuated vaccines include BCG (tuberculosis vaccine), oral polio vaccine (OPV, Sabin), intranasal influenza vaccine, and vaccines against smallpox, measles, mumps, and rubella (MMR), varicella (chickenpox), zoster (shingles), Salmonella typhi, yellow fever, and rotavirus. Educational Objective: Vaccines may be classified according to the table shown below. Only live attenuated vaccines contain real-life weakened bacterial or viral agents that have a rare potential to revert and induce actual disease. Examples include BCG (tuberculosis vaccine), oral polio vaccine (OPV, Sabin), intranasal influenza vaccine, and vaccines against smallpox, measles, mumps, and rubella (MMR), varicella (chickenpox), zoster (shingles), Salmonella typhi, yellow fever, and rotavirus. References: First Aid 2014 page 207]]
Approved	Approved::Yes
Keyword	WBRKeyword::Live attenuated vaccine, WBRKeyword::Oral polio vaccine, WBRKeyword::OPV, WBRKeyword::Sabin, WBRKeyword::Check-up, WBRKeyword::Vaccine, WBRKeyword::Vaccination
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