Vaccines may be administered by any of the following routes, except?

Vaccines may be administered by any of the following routes, except?

• A. Subcutaneously
• B. Intramuscularly
• C. Intraperitoneally
• D. Intranasally

Answer: (C)

Vaccination relies on delivering antigen to tissues where immune cells can recognize it and start an protective response. Subcutaneous and intramuscular routes place the antigen in connective or muscle tissue where antigen-presenting cells readily pick it up and provoke a strong systemic immune response, which is why they’re commonly used. Intranasal delivery targets the mucosal immune system in the nasal passages, helping protection at entry points for many respiratory pathogens. Intraperitoneal administration, however, is not a standard route for vaccines in clinical practice. The peritoneal cavity isn’t a predictable, well-controlled site for antigen uptake, and absorption can be inconsistent. There’s also a higher risk of complications such as injury to abdominal organs or peritonitis, and some vaccines may not produce the desired systemic immunity when given into the peritoneal space. Because of these issues, vaccines are not given intraperitoneally, making that route the exception.

Vaccination relies on delivering antigen to tissues where immune cells can recognize it and start an protective response. Subcutaneous and intramuscular routes place the antigen in connective or muscle tissue where antigen-presenting cells readily pick it up and provoke a strong systemic immune response, which is why they’re commonly used. Intranasal delivery targets the mucosal immune system in the nasal passages, helping protection at entry points for many respiratory pathogens.

Intraperitoneal administration, however, is not a standard route for vaccines in clinical practice. The peritoneal cavity isn’t a predictable, well-controlled site for antigen uptake, and absorption can be inconsistent. There’s also a higher risk of complications such as injury to abdominal organs or peritonitis, and some vaccines may not produce the desired systemic immunity when given into the peritoneal space. Because of these issues, vaccines are not given intraperitoneally, making that route the exception.