42 C.F.R. § 52.3
Who is eligible to apply for a grant?
(a) Persons eligible. Any individual, corporation, public or private institution or agency, or other legal entity shall be eligible for a grant award, except:
(1) An individual or entity which is otherwise ineligible for an award under applicable law or regulation;
(2) Federal agencies or institutions, unless specifically authorized by law to receive the grant; or
(3) Individuals, corporations, institutions, agencies, and other entities during the period they are debarred or suspended from eligibility for Federal financial assistance (see 45 CFR part 76).
(b) Permissible activities within research projects. Any project found by the Secretary to be a research project within the meaning of this part shall be eligible for a grant award. Eligible projects may consist of laboratory, clinical, population, field, statistical, basic, applied or other types of investigations, studies or experiments, or combinations thereof, and may either be limited to one, or a particular aspect of a problem or subject, or may consist of two or more related problems or subjects for concurrent or consecutive investigation and involving multiple disciplines, facilities and resources.
(c) Preferences. In the award of grants for international research relating to the development and evaluation of vaccines and treatments for AIDS under section 2315 of the Act, preference shall be given to:
(1) Activities conducted by, or in cooperation with, the World Health Organization, and
(2) With respect to activities in the Western Hemisphere, activities conducted by, or in cooperation with, the Pan American Health Organization or the World Health Organization.