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...