Hepatitis B vaccines:

Correct Answer: D

Rationale: The correct answer is D) Are very effective if used for post-exposure prophylaxis. Hepatitis B vaccines are not effective in patients with acute hepatitis B (Option A) because the vaccine is designed to prevent infection, not treat active infections. Option B is incorrect because Hepatitis B vaccines are not live attenuated vaccines; they are either recombinant DNA or inactivated virus vaccines. Option C is incorrect as more than $10 \%$ of adults may fail to respond adequately to the Hepatitis B vaccine due to various factors like age, health status, or immune response. In an educational context, it is crucial for nurses preparing for the NCLEX RN exam to understand the specifics of Hepatitis B vaccines, including their efficacy for post-exposure prophylaxis. Post-exposure prophylaxis with the Hepatitis B vaccine is highly effective in preventing infection if administered promptly after exposure to the virus. This knowledge is essential for healthcare professionals to protect themselves and their patients in the event of accidental exposure to Hepatitis B.

Correct Answer: A

Rationale: The correct answer is A) Sub-acute sclerosing pan-encephalitis (SSPE) is a fatal late complication of measles infection. This neurodegenerative disorder occurs years after the initial measles infection, usually affecting individuals who had measles before the age of two. SSPE is a rare but devastating consequence of measles, with a high mortality rate and no cure. Option B) is incorrect because SSPE occurs in about 1 in 10,000 measles cases, not every 25,000. Option C) is also incorrect as the introduction of the MMR vaccine has actually decreased the incidence of SSPE by preventing measles infections. Option D) is incorrect as the risk of developing SSPE is higher in those who had measles infection at a younger age, not after the age of one year. Educationally, understanding the link between measles and SSPE highlights the importance of measles vaccination in preventing not only the acute complications of the disease but also the potential long-term, severe consequences like SSPE. This knowledge underscores the significance of herd immunity and vaccination programs to protect individuals and communities from preventable diseases and their complications.

Correct Answer: C

Rationale: The correct answer is C) It was the commonest cause of viral meningitis in children before 1988. This statement is true because mumps was indeed a leading cause of viral meningitis in children before the introduction of the MMR (measles, mumps, rubella) vaccine in 1988. This historical context is important for understanding the impact of vaccination programs in preventing mumps-related complications like meningitis. Option A is incorrect because not all patients with mumps infection have bilateral swelling of the parotid glands. While parotitis is a common symptom, it may not always present bilaterally. Option B is incorrect because asymptomatic mumps infection can occur. Some individuals may be infected with the mumps virus but remain asymptomatic, making it challenging to identify and control the spread of the infection. Option D is incorrect because while neurological complications can occur as a rare complication of mumps infection, they are typically associated with swelling of the salivary glands. Neurological complications without salivary gland involvement would be atypical in mumps cases. Understanding the manifestations and complications of mumps infection is crucial for healthcare professionals, especially for nurses preparing for the NCLEX RN exam, as it highlights the importance of vaccination in preventing serious outcomes associated with mumps, such as viral meningitis. This knowledge also underscores the significance of public health interventions in controlling infectious diseases and protecting vulnerable populations.

Correct Answer: D

Rationale: The correct answer is D) Pain and induration at the vaccine site can last for 3 days following PPV. This adverse reaction is recognized with pneumococcal vaccines and is important for healthcare providers to be aware of when administering the vaccine. Pain and induration at the injection site are common local reactions to vaccines and typically resolve on their own within a few days. Option A is incorrect because most patients who receive PPV23 do not necessarily develop a mild fever as a recognized adverse reaction. Option B is incorrect because systemic reactions are not quite common with both pneumococcal vaccines; they are more commonly associated with certain individuals or specific circumstances. Option C is incorrect because headache is not a commonly recognized adverse reaction to PPV23. In an educational context, understanding the potential adverse reactions to vaccines is crucial for healthcare professionals to provide proper care and counseling to patients. By recognizing the expected side effects, healthcare providers can appropriately monitor and manage any reactions that may occur, ensuring patient safety and compliance with vaccination recommendations.