The 68-year-old GP and TV presenter told Good Morning Britain' hosts Richard Madeley and Susanna Reid he remained cautions about plans to lift all UK restrictions against the COVID pandemic on 19 July - dubbed Freedom Day - warning it is creating a "factory for other variants".
Dr Hilary said: "Masks is one thing, social distancing is another, vaccination is a third thing.
"We're putting far too much faith in vaccination. Everyone is saying it's a wonderful thing, and it has weakened the link between cases and hospitalisations and deaths... substantially.
"And we would have been in a great position if we were only dealing with the Alpha variant and the Kent variant. But actually, we are dealing with the Delta variant which is much more transmissible.
"We're going to have 50,000 cases, probably, in another few days."
He added: "There are going to be other variants, the more cases we have, we have a factory, a breeding ground, for another variant."
The TV doctor was responding to comments from Madeley and Reid that they intend to continue wearing face masks in public, even if it stops being a legal requirement.
Madeley, 65, said: "Until everyone's been double jabbed, until I sense that people out there are comfortable getting back to a mask-less society. I will wear mine because I totally accept that it's good manners not to spook other people."
Reid, 50, said: "And that's very community minded of you, but there will be plenty of people, yesterday it was 50/50 between our viewers who said they were going to wear a mask. It's now 70/30 on the YouGov poll, but that's still a third of people who won't wear a mask.
"I've already seen a lack of compliance and it's still a requirement. The people who I'm concerned for are not double jabbed, those who are elderly.
"You'll be aware of this Dr Hilary, my parents are in their 80s and I want to know that when they go out there are people who are concerned enough about their health and their vulnerability that they'll continue wearing masks."
Dr Hilary's latest comments come a day after Madeley accused the doctor of misleading viewers of the risks of catching COVID after being double vaccinated.
Dr Hilary had said: "Yes you are absolutely right, we do have the vaccine but what people forget is the vaccination doesn't give you 100% protection.
"10% of people who are double jabbed are still likely to get the virus and are still vulnerable."
Madeley accused the medic of misleading people as he said: "Don’t you think the use of percentages, you're using percentages to make a case here but that’s a bit misleading, because yes the percentage rise in hospitalisations has gone up, I think 24%?
"That sounds a lot, but in real numbers it's starting at a very low level."
Watch: Richard Madeley accused Dr Hilary Jones of 'misleading' viewers with percentages