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...