Symbiosis: The Covert-OP: Symbiosis Series, Book 1 (Unabridged‪)‬

Victor Caraway, vice president of the USA, enlists the help of his trusted friend and lead biochemist at Area 51, Dr. Leonard Mills, to cover up a presumed fatal accident. After examining the body, they discover she's alive, but most likely won't make it. The victim's survival is essential to both and they resort to desperate measures, subjecting her to an experimental treatment using alien DNA.