Vacuum on TOAST table
TOAST table is treated as system table , so you need to query pg_stat_sys_tables, not pg_stat_user_tables:

select relname, vacuum_count, n_tup_del, n_live_tup, n_dead_tup 
from pg_stat_sys_tables 
where relname='pg_toast_147777'


Or you can put it all together, 

select  cl.relname ,vacuum_count, n_tup_del, n_live_tup, n_dead_tup  
 FROM pg_class cl 
 inner join pg_stat_sys_tables st on st.relid = cl.reltoastrelid
 WHERE cl.relname = 'messages1';


Quoting the manual:


  The pg_stat_all_tables view will contain one row for each table in the
  current database (including TOAST tables), showing statistics about
  accesses to that specific table. The pg_stat_user_tables and
  pg_stat_sys_tables views contain the same information, but filtered to
  only show user and system tables respectively.