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...