3 ms·
Demonstrably false - http://www.immune.org.nz/duration-protection-efficacy-and-effectiveness http://www.immune.org.nz/duration-protection-efficacy-and-ef... - t
by edent 12y ago
Demonstrably false - http://www.immune.org.nz/duration-protection-efficacy-and-effectiveness http://www.immune.org.nz/duration-protection-efficacy-and-ef... - there are several vaccines with effectiveness longer than 7 years.