I can't speak to how it would affect the vaccine and the body's response to it, but I can say that giving a vaccine Intravenously is impractical and potentially dangerous at scale. I work in an ER and it can easily take 20+ minutes to start an IV on a patient, especially if they're very young or very old. That's compared to administering Intramuscularly which will take 2 or 3 minutes at most. From what research we've done on vaccines, doing it intramuscularly is perfectly fine so there's just no reason to change that. There's also a greater risk of sepsis going from IM to IV since you're opening a path directly into your bloodstream instead of just near it (again I can't speak to whether or not the vaccine itself would cause issues, but I can't imagine it would help).
Moldy_Teapot t1_j50ndyl wrote
Reply to comment by Silverjeyjey44 in Is there any difference in efficacy when a vaccine is administered somewhere other than the upper arm (e.g. on the foot)? by MercurioLeCher
I can't speak to how it would affect the vaccine and the body's response to it, but I can say that giving a vaccine Intravenously is impractical and potentially dangerous at scale. I work in an ER and it can easily take 20+ minutes to start an IV on a patient, especially if they're very young or very old. That's compared to administering Intramuscularly which will take 2 or 3 minutes at most. From what research we've done on vaccines, doing it intramuscularly is perfectly fine so there's just no reason to change that. There's also a greater risk of sepsis going from IM to IV since you're opening a path directly into your bloodstream instead of just near it (again I can't speak to whether or not the vaccine itself would cause issues, but I can't imagine it would help).