The president of Argentina has just been diagnosed with Covid, with mild symptoms, after being vaccinated with both doses of Sputnik for over a month or two.
We have people in hospital after 2 rounds of Pfizer.
Not all batches should or could be tested but you could do random sample testing.
1: https://factual.afp.com/las-cajas-con-vacunas-sputnik-v-mant...