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...