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...