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...