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...