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...