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...