You are familiar with whey and casein, as well as soya, and probably other vegetable protein powders, such as rice and pea protein. But plasma protein powders are fairly new to the market.
Plasma (also known as serum) protein starts with blood, typically from cows. The red blood cells are removed and the remaining liquid is plasma, or serum if the blood-clotting factors are removed. This liquid is spray-dried and ground into a fine powder that is more than 90% powder. Most of that is from albumin, which is the major protein in blood and is responsible for carrying certain hormones and maintaining blood volume, and from immunoglobulins or antibodies, which fight off foreign invaders in the body. Taking plasma protein can boost your immune system, which can help prevent you getting sick or help you recover quicker from an illness. In fact, University of Barcelona researchers reported that rats infected with the Staphylococcus aureus bacterium, that were given plasma protein powder, produced more anti-inflammatory and fewer inflammatory agents than rats given regular milk proteins, and thus had a better capacity to recover from the infection.
To prevent illness from derailing your training, especially during the flu season, choose plasma (or serum) protein that supplies at least 40% immuniglobulins and add about 10 grams to your pre-workout and post-workout protein shakes. Also add 10 grams to other shakes you have throughout the day.