When I was a kid, they used the needles, but years later, they developed the scratch test. I had
the scratch test around 1977, and it was quite an improvement! Things are probably even better today. Nothing to worry about if they do the scratch test - just light scratches on the back, and everything can be done at once, as opposed to those painful shots, which took weeks and weeks to complete. I hated those shots, which I had at a very young age, about 6 years old.