(20 U.S.C. 6301 et. seq.), as amended by this Act, from programs. authorized under the Elementary and Secondary Education Act. of 1965 (20 U.S.C. 6301 et seq.), as in effect on the day before. the date of enactment of this Act.
The efficacy of a vaccine is different from its effectiveness. It is dependent on several factors such as: 1  adherence to vaccine schedules. 2  the disease â some diseases have vaccines against them that perform better than for other diseases. 3  the strain of vaccine â some vaccine strains are more effective than others.
Measles vaccine. Measles vaccine is a vaccine that is very effective at preventing measles. After one dose 85% of children nine months of age and 95% over twelve months of age are immune. Nearly all of those who do not develop immunity after a single dose develop it after a second dose.