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...