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...