Derivation
variable: meas1date (table[s]: all_vaccination_records [derived table])
variable: birth_date (table[s]: all_vaccination_records [derived table])
*for MEAS1: problem if vacc date is less than 8 months, or more than 12 months after birthdate (supposed to be after 9 months)
if "`vacc'"=="meas1" replace `vacc'Sprob=1 if (meas1date-birth_date<244 | meas1date-birth_date>365) & meas1date~=. & birth_date~=.