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...