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...