Is a new Covid 19 wave about to hit the UK?

What we know about new Omicron sub-variants BA.4 and BA.5 and will lateral flow tests work:

BA.4 and BA.5 were behind a recent wave in South Africa, and is now gaining ground across the United States.

BA.5 is believed to be driving a surge in UK cases and an uptick in hospitalisations in well-vaccinated Portugal.

In the UK 989,800 people in private households were estimated to have had the virus in the week ending June 2. Up from 953,900 the previous week, according to the Office for National Statistics (ONS).

Hospital admissions with Covid are also rising across England, up 10% week-on-week. The BA.4 and BA.5 infections have overtaken Omicron variant BA.2 as of this week.

Is the summer wave about to hit the UK?

We do not know. But what we do know is the vaccines have given the population a level of protection.

What are BA.4 and BA.5?

The BA.4 and BA.5 are sub-variants of Omicron which emerged at the close of 2021. They are the latest variants of Covid-19 that is, like all viruses, continuing to adapt to an increasingly immune population.

BA.4 and BA.5 share many of the same mutations as the original Omicron variant, but have more in common with the BA.2 variant, previously referred to as "stealth Omicron".

But there are notable differences, specifically that their spike proteins - the part of the virus that attaches to receptors on human cells - are different.

Where have Omicron BA.4 and BA.5 cases been found?

BA.4 and BA.5 were first detected in South Africa in January and February 2022.

Since then have become the country's dominant variant.

Portugal now has the world's second-highest Covid infection rate, driven, experts believe, by BA.5. More worryingly, death rates and hospitalisations are also on the rise.

Germany is also seeing cases and the country is preparing for a Covid surge in the autumn.

Sarah Crofts, Head of Analytical Outputs for the Covid-19 Infection Survey, said: “Today’s data shows a mixed picture for infection rates across the UK, with small increases in England and Northern Ireland, likely driven by increasing trends in Omicron BA.4 and BA.5 variants.

“Infections with Omicron BA.2 remain the most common variant of Covid-19 and continue to decrease across much of the UK. We will continue to monitor the data closely.” * Paul Hunter, Professor in Medicine at the Norwich School of Medicine told ITV News, BA.2 infections have been falling since about early April, but cases of BA.4 and BA.5 have been increasing "quite quickly".*

"My guess is, that it was about three days ago they became more than 50% of all cases So what we'll see is that over the next few days, the rate of increase in total cases will get greater, until we get to the point where BA.4 and 5 are by far the dominant, and it will probably take another week or two before we get the most rapid increase," he said.