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...