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...