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...