No, NIAID uses conference awards (R13, U13) to directly support scientific meetings, conferences, and workshops; not attendees. We do prioritize applications that would use funds to facilitate participation of graduate students, postdoctoral trainees, and junior faculty members. For an NIAID-supported scientific meeting, you should ask the organizers whether there are funds available to help with costs like registration, hotel, and airfare.
Find additional details in our Conference Awards SOP. Note that NIAID requires potential applicants to request and receive written permission at least 6 weeks before application submission.