National Institutes of Health

The NIH conducts its scientific research through the NIH Intramural Research Program (IRP) and provides significant biomedical research funding to non-NIH research facilities through its Extramural Research Program. , the IRP had 1,200 principal investigators and more than 4,000 postdoctoral fellows in basic, translational, and clinical research, being the largest biomedical research institution in the world, while, as of 2003, the extramural arm provided 28% of biomedical research funding spent annually in the U.S., or about US$26.4 billion.
The NIH is responsible for many scientific accomplishments, including the discovery of fluoride to prevent tooth decay, the use of lithium to manage bipolar disorder, and the creation of vaccines against hepatitis, ''Haemophilus influenzae'' (HIB), and human papillomavirus (HPV). In 2012, the NIH comprised 27 separate institutes and centers of different biomedical disciplines.
In 2019, the NIH was ranked number two in the world, behind Harvard University, for biomedical sciences in the Nature Index, which measured the largest contributors to papers published in a subset of leading journals from 2015 to 2018. Provided by Wikipedia