Asked whether the discovery of the new variant would have an impact on the next stage of restrictions lifting on June 21, the spokesman said the five-week gap between measures relaxing would allow the variant to be monitored. "So it is vital to get both doses to gain maximum protection against all existing and emerging variants".
People were also allowed to travel overseas to a number of green-list countries without having to quarantine upon return as the ban on foreign travel has also been lifted.
That compared with 93% effectiveness against the B.1.1.7 "Kent" strain which is Britain's dominant Covid variant.
The Public Health England on Sunday said that the difference in effectiveness between the vaccines after two doses may be attributed to the fact that the Oxford-AstraZeneca vaccine was rolled out after the Pfizer shot.
The latest PHE statistics released earlier this week show that case numbers of the B1.617.2 variant had risen by 2,111 over the past week to hit 3,424 cases across the country. "That's really good news".
A nurse holding a bottle of Pfizer coronavirus vaccine.
As the virus changes, protection against infection was always going to be the first thing that slips.
PHE said there are now insufficient cases and follow-up periods to estimate vaccine effectiveness against severe outcomes from the B1.617.2 variant but that it will continue to evaluate this over the coming weeks.
This compared with about 50% effectiveness against the Kent variant.
At the same time NHS Test and Trace said 15,202 people in England tested positive for Covid-19 in the week to May 12th - up five per cent on the previous week and the first seven-day increase since early January.
The more hard question to answer is what this means for the speed of the route back to normality.
"In the face of uncertain evidence the risk of over-reacting seems small compared to the potential benefit of delaying a third wave until more people are vaccinated". The designation will also spur efforts to control the variant's spread and, potentially, development of new diagnostics or the modification of vaccines or treatments.
India on Saturday reported another 257,000 cases and 4,194 deaths in 24 hours, taking its total to 26.2 million infections and 295,525 deaths.
"For the most part, the sky is mostly blue but with a black cloud on the horizon which is the Indian variant", he warned.
Dr Jenny Harries, the chief executive of the UK Health Security Agency, said experts were "increasingly confident" about the effectiveness of vaccines against the strain in preventing severe disease. Around 72% of adults in the United Kingdom have had a first dose, with some 43% fully vaccinated.
Prof Susan Hopkins, PHE's Covid-19 strategic response director, said the data trend was "quite clear" and was heading in the "right direction".