The prime minister said there could be yet another resurgence in deaths from the disease.
Mr Johnson said there is “a high likelihood of a flare-up this winter when the weather facilitates the transmission of all respiratory diseases and when the pressure on our NHS is most acute”.
He added that the country had gone through trauma “like no other” in the battle against the coronavirus.
His comments came as the prime minister announced a full independent investigation into his government’s handling of the pandemic – but it won’t start for a year.
The Prime Minister has finally set a date for the long-awaited investigation, which will begin in spring 2022.
Grieving families and activists have called for an investigation to ensure lessons are learned from the pandemic.
Speaking in the House of Commons, Mr Johnson has so far described the impact of the pandemic and added: ‘In the midst of such a tragedy, the state has an obligation to review its actions too. rigorously and frankly as possible, and to draw all the lessons for the future – which is why I have always said that when the time comes, there should be a full and independent investigation.
“I can therefore confirm today that the government will set up an independent public inquiry on a statutory basis, with full powers under the 2005 Inquiries Act – including the ability to compel the production of all relevant documents and to collect public testimony under oath. ”
He said decentralized administrations would be consulted before the final scope of the investigation was released.
He added, “This process will put state actions under the microscope and we should be aware of the scale of this endeavor and the resources required to do it properly. ”
Regarding the continuing threat of new variants, he added: “If these were found to be highly transmissible and escape the protection of our vaccines, they would have the potential to cause even greater suffering than we endured in January. .
“There is in any case a high probability of a power surge this winter when the weather facilitates the transmission of all respiratory diseases and when the pressure on our NHS is most acute. ”
He added: “So I would expect the right time for the investigation to begin to be at the end of this period in the spring of next year, in the spring of 2022.”
Labor leader Sir Keir Starmer hailed the independent investigation into the pandemic.
Sir Keir highlighted the difficulties faced by families who lost loved ones during the pandemic, including the lack of luck to say goodbye or have a funeral as they wanted.
He said: “It is good that the government consults the decentralized authorities, of course.
“But the government must also consult with families because this investigation will only work if it has the support and confidence of the families. ”
Sir Keir said the government should consult with frontline workers as well.
It comes as NHS sources told the PA news agency that people aged 38 and 39 will be able to book their Covid-19 vaccinations from Thursday morning in England.