The study also provided evidence of the so-called "herd immunity effect" in which unvaccinated older people benefit from the vaccination of children and infants.
This is called herd immunity.
By contrast several rich countries, including America, Britain, France and Italy, are below herd immunity.
The vaccination rate for herd immunity varies by disease, but usually falls between 85% and 95%.
Because no vaccine protects 100 percent of kids who get it, epidemiologists rely on "herd immunity" to make sure enough kids are well enough protected to keep a disease from spreading.
The success of any given vaccine depends on so-called herd immunity, in which a high rate of immunization in a population helps to protect those individuals who are not immune.
Low 'herd immunity'.
There was a very significant negative association between the attack rate and the herd immunity (P
We would provide a herd immunity against every single strain conceivable.
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