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...