COVID-19 cases have risen sharply in the United Kingdom, with 1,739,700 people testing positive in the week ending June 18, according to the UK Office of National Statistics. That’s a 75% increase from the number of cases two weeks earlier. 

The wave of infections may be related to crowds forming for the Queen’s Platinum Jubilee celebrations earlier in June, CNBC reported. 

The UK’s Health Security Agency said Friday that it appears the new Omicron variants BA.4 and BA.5 are driving the increase in infections, with BA.4 now accounting for 22% of cases in the UK and BA.5 accounting for 39%. The ministry said BA.5 will likely become the nation’s dominant COVID strain soon. 

“It is clear that the increasing prevalence of Omicron BA.4 and BA.5 are significantly increasing the case numbers we have observed in recent weeks,” Susan Hopkins, the UKHSA’s chief medical advisor, said Friday. “We have seen a rise in hospital admissions in line with community infections but vaccinations are continuing to keep ICU admissions and deaths at low levels.” 

Luckily, the BA.4 and BA.5 variants are not causing more severe illness than previous strains, the ministry said. The ministry encouraged people to follow safety practices, such as staying home if they test positive, and to keep up with their vaccinations. 

“As prevalence increases, it’s more important than ever that we all remain alert, take precautions, and ensure that we’re up to date with COVID-19 vaccinations, which remain our best form of defence against the virus,” Hopkins said. “It’s not too late to catch up if you’ve missed boosters, or even first doses so please take your recommended vaccines.” 

Meanwhile, authorities in Shanghai declared victory over COVID as the city reported no new local cases for the first time in two months. 

Li Qiang, the city’s Communist Party chief, spoke Saturday at the opening of the city’s party congress and said authorities had “won the war to defend Shanghai,” U.S. News and World Report said. 

Though many restrictions have been lifted in Shanghai, most in-person classes have not resumed and inside restaurant dining is not allowed yet, according to U.S. News and World Report. 

Authorities in Beijing said primary and secondary schools could reopen for in-person classes for the first time since May, when students moved to online learning because of a spike in COVID cases, U.S. News and World Report said. 

Sporting activities for the young will be allowed soon in non-school locations in Beijing if no community cases have been reported in seven days, U.S. News and World Report said. 

While other countries are trying to live with and manage COVID while opening up their economies, China has employed a “zero-COVID” strategy, which involves contact tracing, mass testing and lockdowns to get COVID-19 numbers down to zero.