Wales now has more Covid cases per head than England as infection rates continue to rise. This is likely caused by the more transmittable BA.4 and BA.5 strains of Omicron.
The latest infection survey from the Office for National Statistics (ONS) shows that an estimated 149,700 people - around one in 20 - in Wales had the virus between June 24 and June 30. That is an increase on the one in 30 reported the week before and way up on the one in 75 the week ending June 2. In England, one in 25 were estimated to have the virus in the latest reporting week, in Northern Ireland it was one in 19 and one in 17 in Scotland.
Read more: Wales now has more Covid cases per head than England as infection rates rise
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?
Writing for the The Conversation, Adrian Esterman, professor of biostatistics and epidemiologist at the University of South Australia, said: "We measure how contagious a disease is by the basic reproduction number (R0). This is the average number of people an initial case infects in a population with no immunity (from vaccines or previous infection).
"New mutations give the virus an advantage if they can increase transmissibility: the original Wuhan strain has an R0 of 3.3, Delta has an R0 of 5.1, Omicron BA.1 has an R0 of 9.5, BA.2, which is the dominant subvariant in Australia at the moment, is 1.4 times more transmissible than BA.1, and so has an R0 of about 13.3
"A pre-print publication from South Africa suggests BA.4/5 has a growth advantage over BA.2 similar to the growth advantage of BA.2 over BA.1. That would give it an R0 of 18.6. This is similar to measles, which was until now was our most infectious viral disease."
How likely is reinfection?
BA.4/BA.5 appear to be very good at evading immunity which increases the chance of reinfection. Professor Esterman wrote: "Reinfection is defined as a new infection at least 12 weeks after the first. This gap is in place because many infected people still shed virus particles many weeks after recovery. However, some unfortunate people get a new infection within the 12 weeks, and therefore are not counted. Likely, there are now tens of thousands. into their second or third infections, and this number will only get bigger with BA.4/5."
What are the symptoms for the BA.4 and BA.5 Covid-19 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. The Mirror reported that 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.
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