Connect with us


Coronavirus variants: How alpha, delta and omicron tormented us in 2021



A year ago, many were hoping the pandemic would soon be over – but then came alpha, delta and omicron


24 December 2021

A sign in Hounslow, London, in June 2021

James Veysey/Shutterstock

What a year it has been. In December 2020, the first vaccination campaigns were just getting under way in high-income countries, leading many to hope that life would soon get back to normal. Now a growing number of countries are reimposing restrictions as cases soar to the highest levels since the pandemic began.

The reason for this is, in a word, evolution. The SARS-CoV-2 coronavirus has been spreading largely unchecked through most of the 7 billion people on this planet, giving it countless opportunities to evolve.

The virus has been changing right from the beginning. All but one of the variants that caused us the most grief during 2021 actually appeared in 2020. They were waiting in the wings months before the vaccines began to roll out.

The first of these was beta, which gradually evolved in the Eastern Cape in South Africa in the second half of 2020. Beta could dodge prior immunity to some extent, and it caused a second wave of cases in the region that peaked in January 2021. Beta spread worldwide but didn’t cause major waves in most other countries, probably because other variants had got there first.

In December 2020, the UK sounded the alarm about alpha, first spotted in Kent in September 2020. It had a bunch of new mutations, and was highly transmissible. We still don’t know how it originated but it may have evolved over months in an immunocompromised person.

During the first few months of 2021, alpha caused a big wave of cases in Europe and North America and much of the rest of the world. The main exception was South America, which was instead grappling with gamma, a variant that is thought to have evolved in Brazil in late 2020.

In April 2021, India was hit hard by delta, first detected there in October 2020. For a while, hospitals were overwhelmed.

It soon became clear that delta was even more transmissible than alpha, in addition to having some immune evasion. It spread worldwide, causing another big wave of cases in North America and Europe, and to a lesser extent in the rest of the world. That wave subsided in some regions, but as the northern winter began, case numbers began to climb again.

As delta spread, it outcompeted all other variants. For instance, zeta was a “variant of interest” that caused quite a few cases in South America and spread to at least 44 countries, but it hasn’t been detected since October 2021.

For a while, it seemed that delta would drive all other variants to extinction, and that all future variants would be variants of delta. But then, seemingly out of nowhere, came omicron. It was first detected early in November and has spread with astonishing speed.

We now effectively have two pandemics happening in parallel, with levels of delta remaining high even as omicron spreads. It isn’t clear yet whether omicron will replace delta or if both viruses will continue to circulate, giving rise to yet more variants.

What appears clear is that 2022 is going to begin with a massive global wave of covid-19, and there is every reason to think there will be yet more dangerous variants after omicron.

Sign up to our free Health Check newsletter for a round-up of all the health and fitness news you need to know, every Saturday

More on these topics:

Source link

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published.


Solar storms may cause up to 5500 heart-related deaths in a given year



In an approximate 11-year cycle, the sun blasts out charged particles and magnetised plasma that can distort Earth’s magnetic field, which may disrupt our body clock and ultimately affect our heart


17 June 2022

A solar storm

Jurik Peter/Shutterstock

Solar storms that disrupt Earth’s magnetic field may cause up to 5500 heart-related deaths in the US in a given year.

The sun goes through cycles of high and low activity that repeat approximately every 11 years. During periods of high activity, it blasts out charged particles and magnetised plasma that can distort Earth’s magnetic field.

These so-called solar storms can cause glitches in our power grids and bring down Earth-orbiting satellites. A handful of studies have also hinted that they increase the risk of …

Source link

Continue Reading


UK Covid infection rate rising, with more than a million cases in England | Coronavirus



Coronavirus infections are rising in the UK, figures have revealed, with experts noting the increase is probably down to the more transmissible BA.4 and BA.5 Omicron variants.

The figures from the Office for National Statistics (ONS), based on swabs collected from randomly selected households, reveal that in the week ending 11 June an estimated one in 50 people in the community in England are thought to have had Covid – around 1.13 million people.

The figure is even higher, at one in 45, in both Wales and Northern Ireland, while it was highest in Scotland where, in the week ending 10 June, one in 30 people are thought to have been infected.

While the figures remain below the peak levels of infection seen earlier this year, when around one in 13 people in England had Covid, the findings are a rise on the previous week where one in 70 people in England were thought to be infected. Furthermore, the data reveals increases in all regions of England, except the north-east, and across all age groups.

Experts say that a key factor in the increase is probably the rise of the Covid variants of concern BA.4 and BA.5.

“Infections have increased across all four UK nations, driven by rising numbers of people infected with the BA.4 and BA.5 Omicron variants,” said Kara Steel, senior statistician for the Covid-19 Infection Survey.

While Steel said it remained too early to say if this was the start of another wave, others have warned it may already have begun, with increased mixing and travelling among other factors fuelling a rise in cases.

Among concerns scientists have raised are that BA.4, BA.5 and another variant on the rise, BA.2.12.1, replicate more efficiently in human lung cells than BA.2.

Prof Azra Ghani, an epidemiologist at Imperial College London, said the latest figures were not surprising, and might rise further.

“This increase in infection prevalence is likely due to the growth of the BA.4 and BA.5 Omicron subvariants, which as we have seen elsewhere in Europe, appear to be able to escape immunity generated from previous Omicron subvariants,” she said.

“It is therefore possible that we will continue to see some growth in infection prevalence in the coming weeks and consequently an increase in hospitalisations, although these subvariants do not currently appear to result in any significantly changed severity profile. This does however serve as a reminder that the Covid-19 pandemic is not over.”

Source link

Continue Reading


NHS to offer women in England drug that cuts recurrence of breast cancer | Breast cancer



Thousands of women in England with breast cancer are to benefit from a new pill on the NHS which reduces the risk of the disease coming back.

The National Institute for Health and Care Excellence (Nice) has given the green light to abemaciclib, which cuts the chance of breast cancer returning after a patient has had surgery to remove a tumour.

Trials showed that patients who had the drug with hormone therapy had a more than 30% improved chance of their cancer not coming back after surgery, compared with hormone therapy alone.

“It’s fantastic thousands of women with this type of primary breast cancer will now have an additional treatment option available on the NHS to help further reduce the risk of the disease coming back,” said Delyth Morgan, the chief executive of charity Breast Cancer Now.

“The fear of breast cancer returning or spreading to other parts of their body and becoming incurable can cause considerable anxiety for so many women and their loved ones.

“New effective treatments such as abemaciclib, which can offer more women the chance to further reduce the risk of the disease recurring, are therefore extremely welcome and this is an important step change in the drug options available for this group of patients.”

The twice-a-day pill is suitable for women with hormone receptor-positive, HER2-negative, node-positive early breast cancer at high risk of recurrence who have had surgery. About 4,000 women will benefit initially, Nice said.

Helen Knight, the interim director of medicines evaluation at Nice, said the draft recommendation came less than a month after abemaciclib received its licence.

“The fact that we have been able to produce draft recommendations so quickly is testament to the success of our ambition to support patient access to clinically and cost effective treatments as early as possible,” said Knight. “Until now there have been no targeted treatments for people with this type of breast cancer.

“Abemaciclib with hormone therapy represents a significant improvement in how it is treated because being able to have a targeted treatment earlier after surgery will increase the chance of curing the disease and reduce the likelihood of developing incurable advanced disease.”

Abemaciclib works by targeting and inhibiting proteins in cancer cells which allow the cancer to divide and grow. It normally costs £2,950 for a packet of 56 150mg-tablets, but the manufacturer, Eli Lilly, has agreed an undisclosed discounted price for NHS England.

“Thanks in part to this latest deal struck by NHS England, NHS patients will be able to access another new targeted drug for a common and aggressive form of breast cancer,” said Prof Peter Johnson, the cancer director of NHS England.

“Abemaciclib, when used alongside a hormone therapy, offers a new, doubly targeted, treatment option, helping to increase the chances of beating the cancer for good, as well as meeting the NHS’s commitment to delivering improved cancer care under our long-term plan.”

Source link

Continue Reading