Can cows be crucial to developing HIV vaccines?


A new research revealed that cows’ quick immune response might just be the key to creating a human HIV vaccine.

Scientists have made a huge discovery and a huge step toward developing an HIV vaccine. The experiment was supported by the National Institutes of Health and oddly enough it included cows. Researches discovered that cows can develop HIV neutralizing antibodies (bNAbs) much faster than humans can.

They injected four calves with proteins which were designed to imitate the ones on the surface of HIV and hopefully induct an immune response. Every calf developed bNAbs after just 35 to 50 days. When humans are infected with HIV virus only 10 to 20 percent develop bNAbs and that happens after two years of infection.

More staggering is the fact that, thanks to its immune response, one cow neutralized 20 percent of the HIV strain in 42 days, and that’s not where it stops, another cow neutralized up to 96 percent of the HIV strain in 381 days.

After isolating the antibodies that immunized calves developed, scientists realized that they have a particularly potent antibody that will bind itself to the spot that the HIV virus uses to infect cells. They were also found to have longer loops of HCDR3 that develop at a much higher frequency.

Extended HCDR3 regions have the ability to penetrate the sugar molecules on the HIV’s surface and reach its concealed regions, which leads to ultimately neutralizing. These longer HCDR3 regions can be observed only in people who have lived with HIV for longer periods.

The very quick and effective immune response seen in the calves’ organisms is a significant discovery in the quest to develop a potent HIV vaccine.

So, how are cows able to produce the antigens so fast for the virus that only affects humans? Well, even the scientists are not sure and are still guessing. One theory is that the cows’ gastrointestinal systems are playing a big role in this process. Considering the fact that cows have multi-chambered stomachs that allow them to properly digest their main meal of grass, a possible scenario is that large population of bacteria in their guts are responsible for making such a powerful immune system.

This research did show some incredible results, but the development of an HIV vaccine is still out of sight. Besides the fact that cows are very different from humans, HIV is also human virus, therefore it is not easy to predict how these results will translate to the human immune response.

However, it is very promising development, especially because humans can produce bNAbs only after a long time of living with the infection, and by that time virus is already developing its own immunity to the human defense.