Across the UK, the number of Covid -19 cases continues to sneak up, with infection rates rising once again.
In the three weeks since February 24, infection rates have more than doubled - rising from a little under 39,000 to over 93,000 on March 16. Cases are rising in Wales, England, Scotland and Northern Ireland.
This startling climb has gone largely under the radar, with news elsewhere dominating the headlines.
The spike in cases coincides with a general relaxation of Covid rules across the union and what is likely to be a fade in vaccine protection, as the time since most of the country had their booster jabs wears on.
But it isn’t only these two factors that scientist believe is causing the numbers to creep up again - it is also thought that new variants and sub-variants have contributed, too.
The situation has bred some uncertainty about whether symptoms and levels of contagiousness vary between strains - so read on for a breakdown of what to look out for for the main variants currently ripping across the UK.
What are standard symptoms of Covid-19?
According to the NHS, the main symptoms of Covid-19 are:
- A high temperature – this means you feel hot to touch on your chest or back (you do not need to measure your temperature).
- A new, continuous cough – this means coughing a lot for more than an hour, or three or more coughing episodes in 24 hours (if you usually have a cough, it may be worse than usual).
- A loss or change to your sense of smell or taste – this means you've noticed you cannot smell or taste anything, or things smell or taste different to normal.
It is thought that most people who catch the virus will demonstrate one of these.
What are the symptoms of Omicron (BA.1)?
Omicron ripped through the UK over Christmas and into the new year, causing a huge spike in the number of cases.
It continues to be by far the most dominant strain globally, accounting for 98.8% of all Covid cases submitted to the GISAID global database for tracking the virus since January 25.
The strain infects people's upper airways at an extremely high rate - 70 times faster than the formerly dominant Delta variant.
Five of the most common symptom of this variant are:
- runny nose
- headache
- fatigue
- sneezing
- sore throat
Sanjaya Senanayake, associate professor of medicine and an infectious diseases physician at Australian National University, said that the Omicron variant is more likely than Delta to cause a sore throat but less likely to cause a loss of taste or smell.
Among children, it is more likely to produce a barking cough known as croup. Usually associated with other viruses, Omicron’s infection of the upper airways makes it more likely.
Omicron continues to stalk the UK, threatening vulnerable people. On March 16, 153 people died after contracting coronavirus.
On March 7, the World Health Organisation released a statement saying: "As we enter the third year of the pandemic, SARS-CoV-2, the virus that causes Covid-19, is spreading between people at an intense level globally.
“There are many factors that are driving transmission. One of these is the emergence of highly transmissible variants of concern, the latest being Omicron. The virus continues to evolve and the risk of future emergence of variants is high."
What are the symptoms of Stealth Omicron (BA.2)?
According to the UK Health Security Agency (UKHSA), the sub-variant known as ‘ Stealth Omicron ’ was discovered in December last year and is being treated as a "variant under investigation".
Chief executive Dr Jenny Harries said: "The increasing presence of the BA.2 sub-lineage of Omicron and the recent slight increase in infections in those over 55 show that the pandemic is not over and that we can expect to see Covid circulating at high levels."
Data collected by the Wellcome Sanger Institute says that in the final week of February 2022, the BA.2 variant accounted for 57% of new cases in the UK - meaning that in terms of transmission, it is currently the dominant variant in the UK. There are concerns Stealth Omicron could be even more virulent than its predecessor.
Former WHO epidemiologist Professor Adrian Esterman took to Twitter to post a warning.
"Omicron BA.2 is about 1.4 times more infectious than BA.1. The basic reproduction number (R0) for BA.1 is about 8.2, making R0 for BA.2 about 12. This makes it pretty close to measles, the most contagious disease we know about."
Research coming out of Denmark indicates, at an early stage, that the variant poses a limited threat to human life, and doesn't cause severe symptoms.
It has picked up the ‘stealth’ part of its name over fears that it may be tougher to track, lacking a gene Omicron has that makes spotting the virus easier.
Currently, it isn’t known whether the sub-strain has different symptoms, although indicative reports sent in to the ZOE Covid app suggest symptoms include runny nose, headache, sore throat and fatigue.
Other common Covid indicators include sneezing, a persistent cough, hoarseness, chills or shivers, unusual joint pains, fever, dizziness, brain fog, sore eyes, an altered sense of smell, muscle pains, swollen glands, a loss of appetite and chest pains.
The Covid-19 incident director at UKHSA, Dr Meera Chand, said: "It is the nature of viruses to evolve and mutate, so it's to be expected that we will continue to see new variants emerge as the pandemic goes on. Our continued genomic surveillance allows us to detect them and assess whether they are significant.
"So far, there is insufficient evidence to determine whether BA.2 causes more severe illness than Omicron BA.1, but data is limited and UKHSA continues to investigate.
"Case rates remain high throughout the UK and we must remain vigilant and take up vaccinations. We should all continue to test regularly with LFDs [lateral flow tests] and take a PCR test if symptoms develop."
What are the symptoms of Deltacron?
First rearing its ugly head in January, this Frankenstein-like hybrid has been picked up in the United States and early research indicates it's the product of someone getting infected with both Omicron and Delta variants at the same time.
The variant is thought to be predominantly Delta, but with the addition of an Omicron-originating spike protein.
Few cases have been reported so far.
National director for health protection and screening services at Public Health Wales, Dr Meng Khaw, told WalesOnline : "There is no evidence of vaccine escape issues relating to Deltacron, and the best thing you can do to protect yourself against this and other variants is to take up the offer of coronavirus vaccine.
"You can also protect yourself and others by maintaining a social distance where possible, washing hands regularly, keeping homes well-ventilated, using a face covering, and working from home if you can.
"If you develop a cough, fever, or change in sense of taste or smell, the public health advice remains that you should self-isolate immediately in order to protect others.”
It is not thought this variant has different symptoms to previous forms of the virus.
