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...