Evidence From England

In the UK, the clear cut increase in autism coincides with the introduction of the MMR II in late '88. Higher rates in the 90's reflect improved diagnostic ability to detect PDD.

Study Birth Years AD rate/10,000  
       
Webb('97) ’77 – ’79 3.3  
  MMR II introduced: 10/88    
Webb('97) ’88   9.2  
Kaye ('01) ’93  8  
Kaye (’01) ’90 – ’91  29  
Baird (’00)   30.8  

England: MMR II introduced in October, 1988