BOSTON (Reuters) - The smallpox vaccine protects for a lifetime, and so does actual an infection of measles or mumps, according to the first long-term study of immunity to childhood diseases.And, surprisingly, while a tetanus shot is only supposed to guard against the disease for about 10 years, a team at Oregon Health & Science University found that half the antibodies against the bacterium were still present in the blood 10 years later.
