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...