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...