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...