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Covid booster shots: Third vaccine doses are pushing protection to unexpected heights



Evidence suggests that vaccine booster programmes can take people’s covid-19 protection to unexpectedly high levels, but we don’t yet know how effective existing vaccines will be against the omicron variant


30 November 2021

A road sign in Buckinghamshire, UK, in mid-November

Maureen McLean/Shutterstock

While the emergence of the omicron variant has caused concern worldwide, there is cause for some optimism: emerging evidence on vaccine booster programmes reveals that a third dose can take people’s coronavirus protection to unexpectedly high levels.

It has long been predicted that the covid-19 vaccines from Oxford/AstraZeneca and Pfizer/BioNTech, which were designed as two-dose regimens, may eventually require a third shot. After studies suggested that vaccine effectiveness was waning, many countries began booster programmes, including the UK, which began offering third doses in September to people who are 50 or older and certain other groups. It later widened that to those aged 40 and over.

There was disappointment that boosters were needed after only six months, but the initial signs for how well third jabs are working have been no let-down. In October, a randomised trial found that people who had received a third dose of the Pfizer/BioNTech vaccine had about 95 per cent fewer infections than people who had only had two jabs.

While vaccine effectiveness tends to be lower in the wider world than in trials, real world figures have also been encouraging. In people over the age of 50, those who had a booster were about 93 per cent less likely to have a symptomatic infection than those who were unvaccinated, regardless of whether their first two jabs were AstraZeneca or Pfizer/BioNTech, according to an analysis by the UK Health Security Agency (UKHSA). “It’s really impressive,” says Paul Hunter at the University of East Anglia, UK.

The most recent results from the UKHSA suggest that, in the over 70s, for example, protection levels are now higher than they were in August, and seem to be continuing to rise.

People such as Anthony Fauci, the White House chief medical adviser, have said the covid-19 vaccines should be seen as requiring a three-dose regimen as standard. “A booster isn’t an add-on – a booster is part of what the original regimen should be,” he said at a conference this month.

Several other vaccines require three doses, such as the one against the liver infection hepatitis B. Giving sequential doses takes advantage of the fact that when we repeatedly encounter a pathogen or vaccine, our antibody-making cells undergo a process called “affinity maturation”.

Our antibodies are made by immune cells called B-cells, and during affinity maturation, these multiply within the body’s lymph nodes while undergoing mutations. Only the B-cells that make the best antibodies survive and replicate, so as a result, their progeny make ever-stronger antibodies. “With other infections, the third booster protects you for longer and also gives you antibodies that have higher affinity,” says Hunter.

This is good news for the many countries rolling out booster programmes. But information on the effectiveness of a third dose all relates to the delta variant, so how does the emergence of omicron change things?

Much about omicron is still unclear, but if it does replace delta as the dominant covid-19 variant, its genetic sequence suggests that the existing covid-19 vaccines may be less effective. That doesn’t mean vaccines will become useless, though. “Vaccination is still likely to protect you from severe disease,” Calum Semple, a member of the UK government’s Scientific Advisory Group for Emergencies, told the BBC on 27 November.

That means encouraging as many people as possible to take the full three-dose course of vaccines is still a good plan of action for tackling any covid-19 variant, whether delta or omicron.
On 29 November, the UK’s Joint Committee on Vaccination and Immunisation said that anyone 18 and over can have a booster, in order of descending age groups, and the required interval between second dose and third has shrunk from six months to three. The same day, the US Centers for Disease Control and Prevention said everyone aged 18 and older should get a booster too.

“If you’re boosted, your response is likely to be stronger so it’s more vital than ever that people get their jabs and we get those boosters into arms as fast as possible,” said UK prime minister Boris Johnson on 27 November.

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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 …

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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.”

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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.”

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