Starting Monday, the country dropped several COVID-19 restrictions, reopening non-essential shops and allowing pubs and restaurants to resume outdoor services. The hospitality business also resumed operations as people can now travel inside the country.
"As we unlock, the result will inevitably be that we will see more infections, sadly, we will see more hospitalisations and deaths, and people have just got to understand that," Johnson said during a televised interview.
The prime minister stressed that the drop in new cases and hospitalisations was the result of not the mass vaccination campaign but rather the lockdown and restrictions.
"It is very very important for everybody to understand that the reduction in these numbers, in hospitalisations, and in deaths, and in infections, has not been achieved by the vaccination program. People do not, I think, appreciate that it is the lockdown that has been overwhelmingly important in delivering this improvement in the pandemic," Johnson said.
Since the outbreak of the pandemic last year, the UK has reported more than 4.3 million coronavirus cases, according to the health authorities. The country's COVID-19 death toll stands at 149,968.
The next phase of the UK road map toward easier restrictions is expected to start on May 17. Pubs and restaurants will be allowed to resume indoor services. Up to six people from different households will be allowed to meet indoors if the government's scientific advisers consider that the vaccination program is safely breaking the link between infections and deaths.