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...