THERE  WAS A CROWDSOURCED  VACCINE,  
  THAT COULD BE CREATED REGIONALLY BY   
   MOST   PHARMACEUTICAL   COMPANIES    
   WITHOUT MUCH  EFFORT,  AND IT  WAS   
    ESTIMATED  THAT  IT   HAD   SAVED   
       TENS      OF     MILLIONS.       
                                        
 BUT IT WAS NOT OFFICIALLY RECOGNIZED  BY 
 THE  WORLD HEALTH ORGANIZATION,  AND  AS 
 SUCH DID  NOT GIVE  WHAT THE  SANCTIONED 
 (AND   UNOBTAINABLE)   ONES   DID:   THE 
 SUBSKIN CHIP  THAT  WOULD  LET YOU ENTER 
       (OR     LEAVE)     CITIES.       
                                        
  AND THAT'S WHY, EVENTUALLY, WE WOULD  
  CREATE  OUR  OWN CHIPS.  THEY  WERE   
  LARGER THAN THE OFFICIAL ONES, AND A  
   LITTLE   UNSTABLE,   AND   NEEDED    
    MAINTENANCE.  BUT  THEY  WORKED!    
   OR, THEY WOULD WORK TOGETHER WITH A  
  LITTLE SOMETHING  TO  MAKE THE GUARD  
      LOOK    THE    OTHER    WAY.      
                                      
                                      
                                          
   BUT THE SCANNER SHOWED GREEN, SO...