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...