In Jan. 1961, I, along with 150 others, turned up at Locking for apprentice training. On the second day, we were marched to sick quarters for our jabs. In one of the wards some trestle tables had been set up in two rows, end to end with a row of benches between them. The idea was that you sat astride the benches and shuffled down between the tables whilst being jabbed in either arm by the SSQ staff. At the end of the rows was a separate table, manned by civvies, who gave us all an additional jab. All the RAF mannned tables told you what you were getting and it appeared on our jab sheets. Nobody mentioned what the last jab was for and no mention on the jab sheet. Still talked about at reunions.