Do you need to aspirate before giving a vaccination?

No. ACIP does not recommend aspiration when administering vaccines because no data exist to justify the need for this practice. There are data that show that aspiration is more painful for the vaccine recipient. IM injections are not given in areas where large vessels are present. Given the size of the needle and the angle at which you inject the vaccine, it is difficult to cannulate a vessel without rupturing it and even more difficult to actually deliver the vaccine intravenously. We are aware of no reports of a vaccine being administered intravenously and causing harm in the absence of aspiration.