Cows have a very well evolved immune system that produces rare antibodies which have the potential to neutralize human immunodeficiency virus.
Scientists at the International Aids Vaccine Initiative and the Scripps Research Institute have discovered that although cows do not contract HIV infection, when injected with HIV proteins their immune system produce the broadly neutralizing antibodies (bNA’s) which are required to fight against or neutralize the potent virus. The possible origin of these antibodies could be from the multi-chambered stomachs of the cows containing abundant range of bacteria that enables them to breakdown and digest grasses.
10-20% Humans also produce these antibodies but at a much later stage and up until then viruses mutate or develop resistance to them. The antibodies from cows will have to be modified for use as a vaccine in humans but atleast the potential has been realized. National Institute of Health defined this research as a truly remarkable stride in the quest for finding a cure for HIV.
Devin Sok et al 2017. Rapid elicitation of broadly neutralizing antibodies to HIV by immunization in cows. Nature doi:10.1038/nature23301