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...