The Prime Minister said it was a boost for efforts to keep the June 21 date for the further easing of lockdown restrictions.
Mr Johnson added that the latest data indicates the jabs are working against all variants of the virus.
The spread of the B1617.2, known as the Indian variant, had cast doubt on next month’s plans to ease the remaining restrictions in England.
However, Mr Johnson has said there is no conclusive evidence to suggest a deviation from the road map.
In a further sign of optimism, the Prime Minister told MPs on Wednesday: “We’ve looked at the data again this morning and I can tell the House we have increasing confidence that vaccines are effective against all variants, including the Indian variant.”
Mr Johnson thanked people in Bolton and Blackburn – Indian variant hotspots – for “coming forward in record numbers” to receive a jab.
Travel to ‘amber list’ countries
Sir Keir Starmer said “absolute clarity” is needed over whether or not people should travel to amber list countries before highlighting mixed messages given by ministers on Tuesday.
The Labour leader said: “The Government has lost control of the messaging.”
Boris Johnson replied in the Commons: “We are trying to move away from endlessly legislating for everything and to rely on guidance and asking people to do the right thing.
“It is very, very clear – you should not be going to an amber list country except for some extreme circumstance, such as the serious illness of a family member.
“You should not be going to an amber list country on holiday.”