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...