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...