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...