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...