The viral infection hepatitis A can be most effectively controlled if:

• A. Antibiotics are administered after infection
• B. Individuals are vaccinated before exposure to the virus
• C. Infected individuals are treated with antiviral drugs
• D. Only symptomatic individuals are isolated

Answer: (B)

Verified step by step guidance

1. Understand the nature of hepatitis A: it is a viral infection primarily transmitted through the fecal-oral route, often via contaminated food or water.
2. Recognize that antibiotics are ineffective against viruses because they target bacterial structures and processes, so administering antibiotics after infection will not control hepatitis A.
3. Consider the role of vaccination: vaccines stimulate the immune system to develop protection before exposure to the virus, preventing infection or reducing severity.
4. Evaluate treatment options: antiviral drugs are generally not used for hepatitis A because the infection is usually self-limiting and resolves on its own.
5. Understand isolation measures: isolating only symptomatic individuals may not be sufficient because asymptomatic carriers can still spread the virus; therefore, vaccination before exposure is the most effective control method.