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...