You can digest raw egg whites - though perhaps not completely (http://www.fnri.dost.gov.ph/htm/eggmyths.htm).

You are not likely to get a biotin deficiency from eating raw egg whites unless you eat only raw egg whites (in which case, you will likely have numerous nutritional deficiencies).

The risk of salmonella poisoning from raw, or undercooked, eggs is not insignificant. You should limit your consumption of raw eggs to reduce the risk of Salmonella poisoning.