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...