Australian researchers claim they have developed milk that protects human cells from the Human Immunodeficiency Virus (HIV).

The team, led by Dr Marit Kramski of the University of Melbourne’s Department of Microbiology and Immunology, vaccinated pregnant cows with an HIV protein and studied the first milk that cows produced after giving birth.

The first milk, called the bovine colostrum, is naturally packed with antibodies to protect the newborn calf from infections. The vaccinated cows produced milk that contains antibodies which defend against HIV.

“We were able to harvest antibodies specific to the HIV surface protein from the milk,” said Dr Kramski, lead author of a paper published in the journal Antimicrobial Agents and Chemotherapy.

“We have tested these antibodies and found in our laboratory experiments that they bind to HIV and that this inhibits the virus from infecting and entering human cells.”

Cows cannot contract HIV, but their immune systems develop antibodies against the foreign protein.

According to the scientists, the HIV-inhibiting antibodies from cows’ milk will be developed into a cream called a microbicide that is applied into the vagina before and /or after sex to protect women from contracting sexually transmitted infections.

Other microbicides are being developed around the world but the antibodies in this study are easier and cheaper to produce, providing a new HIV-prevention strategy.

“We hope that our anti-HIV milk antibodies will provide a user-friendly, female-controlled, safe and effective tool for the prevention of sexually acquired HIV infection,” Dr Kramski said. “If proven effective in humans, it will empower women to protect themselves against HIV.”

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Bibliographic information: Marit Kramski et al. 2012. Hyperimmune bovine colostrum as a low-cost, large-scale source of antibodies with broad neutralizing activity for HIV-1 Envelope with potential use in microbicides. Antimicrobial Agents and Chemotherapy, vol. 56, no. 8, 4310-4319; doi: 10.1128/AAC.00453-12