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...