Most vaccines currently administered are delivered by intramuscular injection. Yet the pathogenic organisms these vaccines aim to protect against usually enter the body by a different route. For instance, many viruses infect us via the respiratory tract, and many bacterial pathogens infect via the gastrointestinal tract. One major advantage of delivering vaccines against these organisms via their normal route of infection would be:
A) That the vaccines would no longer require the incorporation of an adjuvant in their composition
B) That the vaccines would elicit IgA antibodies in addition to IgG antibodies
C) That the vaccines would no longer require several boosters to elicit protective responses
D) That the vaccines would be more stable and not require refrigeration
E) That the vaccines would be safer and have fewer side effects than injected vaccines

Question

Quizplus · Accepted Answer

Delivering vaccines via their normal route of infection would enable the elicitation of IgA antibodies in addition to IgG antibodies. While IgG antibodies are effective against pathogens circulating in the blood, IgA antibodies are more effective against pathogens located at the mucosal surfaces, such as in the respiratory and gastrointestinal tracts. This would enhance the effectiveness of the vaccine in preventing infection.

Most Vaccines Currently Administered Are Delivered by Intramuscular Injection