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...