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...