By ADRIANA DIAZ FOR DAILYMAIL.COM PUBLISHED: 01:54 EST, 22 December 2021 | UPDATED: 10:05 EST, 22 December 2021 After nearly two years, scientists at the Walter Reed Army Institute of Research believe they have developed a vaccine that is effective against all COVID and SARS variants. Researchers at the Maryland-based facility expect to officially announce the completion of the...