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...