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...