Experts say that two new Omicron sub-variants are causing a worrying rise in new cases, with one-in-21 Brits believed to be infected.
BA.4 and BA.5 have already triggered a rise in infections in the UK, with experts warning that the country is already in the midst of its fifth coronavirus wave.
Covid cases have risen quite significantly in recent weeks following a huge surge after the Jubilee Bank Holiday weekend where cases skyrocketed by 43 per cent.
And experts are warning that big summer events such as festivals will only increase the number of cases even more.
Healthcare workers have already expressed concern that another big wave will pose significant challenges for an NHS that's already struggling.
The two new strains were found in South Africa in January and February this year and are considered to essentially be the grandchildren of the Omicron variant that hit the UK and spread across the world at the end of 2021.
How infectious are the variants?
BA.4 and BA.5 have three mutations to their spike proteins which, it is believed, enables them to retrain their attack on human lung cells.
It's believed the variants are therefore potentially more serious than Omicron but not as transmissable - although no new symptoms have been identified at this stage.
When the Omicron variant hit the UK it spread very quickly, with many people forced to change or cancel plans over the Christmas period as they or family members came down with the virus.
But the Alpha and Delta variants, while less infectious, were potentially more dangerous than Omicron - and studies show BA.4 and BA.5 are more like Alpha and Delta.
What impact are they having on cases?
According to the latest figures from the ZOE Covid Study, there are currently 285,507 new symptomatic cases every day in the UK on average each day.
This is up over a quarter from the 225,464 reported last week and paints a worrying picture.
The recent increases in the UK is primarily due to a subvariant of Omicron. The BA.5 variant which is now dominant in the UK.
The latest wave is being driven by the newer variants BA.4 and BA.5, which now make up more than half of all new Covid-19 cases in England.
Research published by the UK Health Security Agency (UKHSA) suggests BA.5 is growing approximately 35 per cent faster than BA.2 while BA.4 is growing 1 per cent faster.
This means it is likely that BA.5 will soon become the dominant Covid-19 variant in the country.
The No 10 spokesman added that their emergence was “likely the driving cause for the rise in cases", but that the Covid vaccinations are meaning the uptick in cases is not translating to ICU admissions or death.
He told the Evening Standard: “The latest data suggests that these are now the dominant strains in the UK. But, so far, vaccination means those rising cases haven’t translated into a rise of severe illness or death with no increase in ICU admissions.”
Professor Susan Hopkins, UKHSA chief medical adviser, said: "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.
"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."
What are the symptoms of the new variants?
The European Centre for Disease Prevention and Control labelled BA.4 and BA.5 as 'variants of concern' in mid-May this year.
Yet there has been nothing to suggest these sub-variants come with new symptoms. There is "currently no evidence" the two variants cause more serious illness than previous variants according to the UKHSA.
And as with the initial Omicron in winter last year, these sub-variants still seem to be leading to fewer deaths and hospitalisations.
Even if you have been fully vaccinated, you can still experience any or all symptoms of Covid, including the new Omicron variants.
Symptoms include:
- Cough
- Runny nose
- Sore throat
- Fatigue
- Headache
- Muscle pain
- Sneezing
- Pain
While some symptoms do overlap, it is slightly different to the Alpha variant. Those suffering with Alpha were more likely to experience shortness of breath and a loss of taste or smell in addition to some of these listed symptoms like a cough and headache.
Are they able to get around vaccines?
It is unknown at this stage how effective, if at all, the Covid vaccines will be on the sub-variants.
The mutations within BA.4 and BA.5 could mean they can get around anti-bodies gained from past infections and vaccines, therefore enabling them to overcome immunity.
Crucially this fact remains unknown at this stage.
But an initial study by Professor Kei Sato at the University of Tokyo, Japan does suggest the new sub-variants could cause problems when it comes to immunity.
The Professor said: "Altogether, our investigations suggest that the risk of [these] Omicron variants, particularly BA.4 and BA.5, to global health is potentially greater than that of original BA.2."
The BA.2 variant of Omicron has also been referred to as 'stealth Omicron' because it is so contagious.