The correct answer is choice B. 1 ml syringe, 25-gauge needle, vastus lateralis muscle.This is because the vastus lateralis muscle is the preferred site for intramuscular injections in infants, and a 25-gauge needle is appropriate for the viscosity of the hepatitis B vaccine.A 1 ml syringe can deliver the required dose of 0.5 ml for newborns.

Choice A is wrong because the anterolateral aspect of upper thigh is not a recommended site for intramuscular injections in infants.

Choice C is wrong because the deltoid muscle is not well developed in infants and may not have enough muscle mass to absorb the vaccine.

Choice D is wrong because the ventrogluteal muscle is not a recommended site for intramuscular injections in infants, and a 23-gauge needle may cause more pain and tissue damage than a 25-gauge needle.

The correct answer is A.“Yes, you need to get vaccinated because HBV can be transmitted from mother to child during pregnancy or delivery.” This statement is correct because HBV is a blood-borne virus that can infect the fetus through the placenta or during birth.Vaccination can prevent HBV infection and its complications, such as chronic liver disease or cancer.

Statement B is wrong because HBV is a serious disease that affects the liver and can cause inflammation, scarring, cirrhosis, or failure.

Statement C is wrong because although HBV can cause chronic liver disease or cancer in later life, this is not the main reason for vaccination during pregnancy.The main reason is to prevent transmission to the baby.

Statement D is wrong because HBV is not only spread through contact with infected blood or body fluids, but also through sexual contact, sharing needles, or from mother to child.

Normal ranges for HBV tests are:

• HBsAg (hepatitis B surface antigen): negative

• Anti-HBs (antibody to hepatitis B surface antigen): positive after vaccination

• Anti-HBc (antibody to hepatitis B core antigen): negative

• HBeAg (hepatitis B e antigen): negative

• Anti-HBe (antibody to hepatitis B e antigen): positive after recovery

• HBV DNA: undetectable

The correct answer is choice C. The infant should receive the second dose of the hepatitis B vaccine at 4 months of age.This is based on the recommended 3-dose vaccine series for infants, which includes a birth dose, a second dose at 1 month, and a third dose at 6 months.The 4-dose combination vaccine series, which includes a pentavalent or hexavalent vaccine, also requires a birth dose, followed by doses at 6 weeks, 4 months, and 6 months.

Choice A is wrong because 1 month is too early for the second dose.The minimum interval between the first and second doses is 4 weeks.

Choice B is wrong because 2 months is also too early for the second dose.The minimum interval between the first and second doses is 4 weeks, and the second dose should be given at least 8 weeks after the first dose.

Choice D is wrong because 6 months is too late for the second dose.The second dose should be given at least 8 weeks after the first dose, and the third dose should be given at least 8 weeks after the second dose and at least 16 weeks after the first dose.

The correct answer is choice A and B.

Hepatitis B vaccine and hepatitis B immune globulin (HBIG) are the recommended interventions for a person who has been exposed to hepatitis B virus (HBV) through a distinct, identifiable exposure to blood or body fluids that contain blood.Hepatitis B vaccine provides active immunity by stimulating the production of antibodies against HBV, while HBIG provides passive immunity by giving temporary antibodies from another source.

Choice C is wrong because antiviral medication is not indicated for postexposure prophylaxis of HBV, but rather for the treatment of chronic HBV infection.

Choice D is wrong because antibiotics are not effective against viral infections such as HBV.

Choice E is wrong because blood transfusion is not a preventive measure for HBV infection, but rather a potential source of exposure to HBV and other bloodborne pathogens.