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...