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...