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...