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...