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...