‘The good news about that is that the acceleration of the response goes way up. I mean even better than what you get with the two doses together. In other words, it goes up and up and then if you give a boost, it goes way up,’ he said.

‘I don’t know for certain, but that could mean that you induce a response that’s high enough – and durable enough – that you may not have to worry about what people are concerned about, needing a so-called boost every year or so.’

He continued: ‘I would hope that the degree of elevation of response that we will see with the boost might actually give us a lot of wiggle room of not necessarily needing a boost often.’

‘But I have to be, as you say, we are humble and we are modest about it. We don’t know the answer to that.’