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...