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...