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...