Career
He represented Hungary in Chess Olympiads:
In 1926 in 2nd unofficial Chess Olympiad in Budapest – team gold medal and individual 11th place (1st FIDE Masters);
In 1927 at third board in 1st Chess Olympiad in London (+5 –3 =5) team gold medal;
In 1928 at third board in 2nd Chess Olympiad in The Hague (+6 –1 =9) team gold medal;
In 1930 at third board in 3rd Chess Olympiad in Hamburg (+7 –3 =4) team silver medal;
In 1931 at third board in 4th Chess Olympiad in Prague (+4 –4 =7) team 10th place;
In 1933 at third board in 5th Chess Olympiad in Folkestone (+4 –3 =4) team 5th place;
In 1936 at seventh board in 3rd unofficial Chess Olympiad in Munich (+5 –0 =10) team gold medal;
In 1937 at reserve board in 7th Chess Olympiad in Stockholm (+0 –2 =2) team silver medal. Vajda was awarded the International Master (IM) title in 1950.