| Value | Category | 
                                    
                    
                        | 0 | sin información | 
                                    
                    
                        | 4444 | tarjeta indica que si hay vacuna, no hay fecha | 
                                    
                    
                        | 6666 | recibio, segun madre | 
                                    
                    
                        | 9998 | no sabe/no recuerda | 
                                    
                    
                        | Sysmiss |  | 
                            
            Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.