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...