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UAE

COVID-19 infected people who have not developed adequate antibodies may still need vaccine

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Abu Dhabi: People infected with COVID-19 who have not developed adequate antibodies will be given the COVID-19 vaccines in the UAE, it was announced during the UAE Government COVID-19 briefing on Tuesday.

“Often, people who had severe or moderate [COVID-19] infections and symptoms that required hospitalisation developed adequate immunity. This can be checked through the detection and examination of their immunity,” announced Dr Omar Al Hammadi, official spokesman of the UAE Government.

“If the immunity tests are positive, they would not require vaccination. However, if antibodies are not formed, they would be given the vaccine,” he added.

The official also clarified whether some people who have previously been infected by COVID-19 may not have immunity to Sars-CoV-2.

“According to studies, those who had minor [COVID-19] infections, or did not show symptoms during infection with the virus, don’t necessarily have immunity against it. The vaccination of infected people depends mainly on the recommendation and evaluation of specialists,” Dr Al Hammadi said.

Precautionary measures

The official also called upon residents to adhere to all precautionary measures.

“Currently, there is a winter vacation [ongoing] that coincides with school holidays, which will increase social and tourism activities. Although students need to be active and enjoy recreation time with family and friends, we call on everyone to adhere and to follow all of the preventive measures,” Al Hammadi said.

“We want to continue social distancing, handwashing and sanitisation, mask wearing and being careful when coming in contact with the elderly and people with chronic diseases. Cooperation is required and important, especially in places where gatherings may occur during the vacation period,” he urged during the briefing.

“During December 9 to 15, 1,023,607 tests were performed nationwide, with positive cases remaining at an overall rate of one per cent. The death rate during this period was 0.3 per cent, which is one of the lowest in the world, compared to the European Union, the Middle East and North Africa, and the Organisation of Economic Cooperation and Development (OECD) countries,” Dr Al Hammadi said.

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Headline USA

COVID-19: People with antibodies ‘ARE protected against reinfection’


People who have previously caught the coronavirus and have antibodies are unlikely to get infected again within six months, a NHS study shows. 

Research from Oxford University Hospitals looked at 12,180 healthcare workers in Oxford hospitals from April through to November. 

Antibody tests revealed 1,246 workers had already caught the virus by the time the study started, but none had symptoms. Only three (0.24 per cent) of these people later tested positive, and none of them went on to develop symptoms. 

Researchers say the study indicates ‘prior SARS-CoV-2 infection offers protection from reinfection, in the short term’. 

Antibody tests revealed 1,246 workers had already caught the virus by the time the study started, but none had symptoms. Only three of these people later tested positive, and none had symptoms 

Regular testing also revealed 89 of the 11,052 people who had not been infected before later developed an infection and symptoms. 

A further 76 members of staff who had not previously been infected then tested positive but were asymptomatic. 

So in total, 168 (1.49 per cent) of those with no prior infection went on to either test positive for the disease or exhibit symptoms.

The study, published online today as a pre-print, shows that people who have already been infected are highly unlikely to catch the virus again.

One of the authors of the paper, Professor David Eyre of the University of Oxford’s Nuffield Department of Population Health, said: ‘This ongoing study involving a large cohort of healthcare workers has shown that being infected with COVID-19 does offer protection against re-infection for most people for at least six months.

A study had previously found that antibody levels drop rapidly following infection and reach half their original number after just 85 days (pictured). However, the latest study is encouraging that the base level of antibodies is sufficient to prevent reinfection

A study had previously found that antibody levels drop rapidly following infection and reach half their original number after just 85 days (pictured). However, the latest study is encouraging that the base level of antibodies is sufficient to prevent reinfection

REVEALED: THE TRUTH ON COVID IMMUNITY, ANTIBODIES AND T CELLS 

Antibodies are substances produced by the immune system which store memories of how to fight off a specific virus. 

They come in different forms and may attack viruses and destroy them themselves, or may force the body to produce other kinds of immune cells and white blood cells to do the dirty work for them. 

They can only be created if the body is exposed to the virus by getting infected for real, or through a vaccine or other type of specialist immune therapy.

Once antibodies have been created once – the body essentially moulds them around a virus when it encounters one in the blood – the body usually retains a memory of how to make them and which ones go with which virus. 

Generally speaking, antibodies produce immunity to a virus because they are redeployed if it enters the body for a second time, defeating the bug faster than it can take hold and cause an illness. 

Scientists are still unsure on the truth on immunity because Covid-19 has only been around since January – meaning its long-term effects are still unclear.

So far cases of people getting infected more than once have not been numerous nor convincing.

With some illnesses such as chickenpox, the body can remember exactly how to destroy it and becomes able to fend it off before symptoms start if it gets back into the body. But it is so far unclear how long Covid-19 patients are protected for. 

Evidence is beginning to suggest that antibodies disappear in as little as eight weeks after infection with the coronavirus, scientifically called SARS-Cov-2. 

However, antibodies are only one type of substance that can produce immunity. The immune system is a huge web of proteins that have different functions to protect the body against infection. 

T cells — which can’t be detected by the ‘have you had it’ antibody tests — made in response to the infection may offer a form of immunity that lasts several times longer.

T cells are a type of white blood cell that are a key component of the immune system and help fight off disease. 

Other scientific studies have shown people who have had a common cold in the past two years have T cells that show ‘cross-reactive protection’ against Covid-19.

‘We found no new symptomatic infections in any of the participants who had tested positive for antibodies, while 89 of those who had tested negative did contract the virus. 

‘This is really good news, because we can be confident that, at least in the short term, most people who get COVID-19 won’t get it again.’

A study had previously found that antibody levels drop rapidly following infection and reach half their original number after just 85 days. 

The decline continues and the amount of antibodies falls below detectable levels in most people 137 days after their peak reading.

But Professor Eyre says the latest finding shows ‘there is some immunity in those who have been infected’. 

After the previous study, concerns were raised that antibody levels may drop too low and recovered Covid-19 patients would be vulnerable to reinfection. 

However, it is possible the reduction in antibody levels doesn’t mean they vanish, just that they drop below the detectable level. 

Also, if the concentration of antibodies is extremely low, the immune system has a memory function, called B cells, which remembers how to make the antibodies and churn them out rapidly if it recognises the virus again. 

The Oxford clinicians say it is too soon to say whether or not there is long-term protection beyond six months, but call the findings ‘encouraging and exciting’. 

Dr Katie Jeffery, Director of Infection Prevention and Control for Oxford University Hospitals said: ‘This is an exciting finding, indicating that infection with the virus provides at least short-term protection from re-infection – this news comes in the same month as other encouraging news about COVID vaccines. 

‘I would like to thank all our staff who have shown great commitment in attending our clinics for repeated swab and antibody testing in order to keep our patients and each other safe.’ 

A separate study, published earlier this month, looked at the complete cellular response in Covid-19 patients following infection.  

A group of more than 2,000 people working for Public Health England volunteered to take part in the study and donate blood every month, with the first people recruited in early March, before lockdown was announced. 

A total of 100 people tested positive for SARS-CoV-2, the virus which causes Covid-19, but none were hospitalised. More than half (56 per cent) had symptoms. 

All 100 people had high Covid-specific T cells six months later, mirroring the findings from the latest antibody study, but the antibody number in this cohort had dropped below detectable levels. 

Dr Shamez Ladhani, co-author of this paper, said at the time: ‘Early results show that T-cell responses may outlast the initial antibody response, which could have a significant impact on COVID vaccine development and immunity research.’



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Technology UK

Strange case sees kids develop Covid antibodies without ever testing positive


Three children in one family in Australia have developed Covid antibodies, despite testing negative for coronavirus.

Researchers from the Murdoch Children’s Research Institute have detailed the unusual case in a new report.

The parents had tested positive and were showing symptoms for coronavirus, after attending an interstate wedding without their children.

Despite being in close contact with their infected parents, none of the three children tested positive for the virus.

However, antibody tests revealed that all family members had antibodies in their saliva.

Despite being in close contact with their infected parents, none of the three children tested positive for the virus

Usually, a positive antibody test indicates that you’ve previously been infected with Covid-19.

The NHS explained: “Your body makes antibodies when you get an infection. They help fight the infection. If you have coronavirus antibodies in your blood, it’s likely you’ve had the virus before.”

Dr Melanie Neeland, who led the laboratory-based aspect of the report, said: “The youngest child, who showed no symptoms at all, had the strongest antibody response.

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“Despite the active immune cell response in all children, levels of cytokines, molecular messengers in the blood that can trigger an inflammatory reaction, remained low. This was consistent with their mild or no symptoms.”

Thankfully, all family members fully recovered without the need for medical care.

Professor Nigel Crawford, who worked on the study, said: “Investigating immune responses to SARS-CoV-2 across all age groups is key to understanding disease susceptibility, severity differences, and vaccine candidates.”





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Health

Some COVID Patients See Faster Recovery, More Immunity


By Cara Murez
HealthDay Reporter


FRIDAY, Nov. 6, 2020 (HealthDay News) — Certain COVID-19 patients not only recover faster from the coronavirus, but their bodies also show longer-lasting immunity, according to a new study.


“We’ve found a subset of individuals that heal quickly while sustaining virus-specific antibody levels after COVID-19,” said Dr. Duane Wesemann. He’s an associate physician at Brigham and Women’s Hospital in Boston and an associate professor at Harvard Medical School.


“The kind of immune response we’re seeing in these individuals is a bit like investing in an insurance policy — it’s the immune system’s way of adding a potential layer of protection against future encounters with the virus,” the immunologist said in a hospital news release.


For the study, the researchers collected blood samples monthly from 92 people in the Boston area who had recovered from mild to moderate bouts of the coronavirus between March and June 2020.


The team analyzed the blood samples, measuring a range of antibodies against the virus, including immunoglobulin-G (IgG). The investigators split the group into two categories, depending on whether the participants sustained their antibody levels for several weeks or lost them. Most lost their IgG levels within three to four months, the findings showed, but 20% had antibody production that was stable or even enhanced over that time.


The researchers learned that the “sustainers” had symptoms for an average of 10 days, and also had differences in two types of immune cells (memory T cells and B cells) that play a key role in immune memory and protection, compared to those whose antibodies decayed. The “decayers” had virus symptoms for an average of 16 days.


“The data point to a type of immune response that’s not only adept at handling viral disease by leading to a swift resolution of symptoms, but also better at producing cells that can commit to longer-term production of antivirus IgG antibodies,” Wesemann said.


“Figuring out how these individuals are able to support longer-term antibody production is relevant to COVID-19, and will also have important implications for our understanding of the immune system in general,” he added.


The results were published online Nov. 3 in Cell.



More information



Visit the U.S. Centers for Disease Control and Prevention to learn more about COVID-19 research.











SOURCE: Brigham and Women’s Hospital, news release, Nov. 3, 2020



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Technology UK

Children and adults produce different antibodies in response to coronavirus


Children and adults produce different types and amounts of antibodies in response to coronavirus, a new study has revealed.

Researchers from Columbia University say the findings could explain why children tend to experience less severe infection than adults.

Dr Matteo Porotto, who co-led the study, said: “In kids, the infectious course is much shorter and probably not as disseminated as in adults.

“Kids may clear this virus more efficiently than adults and they may not need a strong antibody immune response to get rid of it.”

In the study, the researchers analysed 47 children and 32 adults who had tested positive for coronavirus.

The existing drugs could be used to treat coronavirus

The analysis revealed that compared with adults, children produced fewer antibodies against the virus’ spike protein, and had less neutralising activity.

Dr Donna Farber, co-lead author of the study, explained: “There is a connection between the magnitude of your immune response and the magnitude of the infection: The more severe the infection, the more robust the immune response, because you need to have more immune cells and immune reactions to clear a higher dose of a pathogen.”

Meanwhile, children were also shown to produce fewer antibodies against a viral protein that’s only visible to the immune system after the virus infects human cells.

Dr Porotto said: “Because children clear the natural virus rapidly, they do not have a widespread infection and they do not need a strong antibody response.”

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The findings suggest that children should respond well to vaccine.

Dr Farber added: “Even though children don’t produce neutralizing antibodies in response to a natural infection with SARS-CoV-2, vaccines are designed to generate a protective immune response in the absence of an infection.

“Children respond very well to vaccines, and I think they will develop good neutralizing antibody responses to a SARS-CoV-2 vaccine, and they’ll probably be better protected than the adults.

“That said, very few vaccine studies are currently enrolling children and we will need this data to really understand how well the vaccines work in children.”





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Headline USA

Llamas make tiny ‘nanobodies’ that are ‘many times more powerful’ than human coronavirus antibodies


Tiny but powerful antibody fragments from llamas have the potential to treat and cure COVID-19, a new study suggests.

The llama antibodies, called ‘nanobodies,’ are several times smaller than antibodies produced by humans but more effective at neutralizing the coronavirus. 

Researchers found that just a fraction of a nanogram – smaller than can be seen by the naked eye – can prevent up to one million cells from becoming infected.

The team, from the University of Pittsburgh School of Medicine, says this therapy is easier, faster and cheaper to use than traditional antibodies and can be delivered directly to the lungs to prevent the virus from causing any damage.

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In a new study from the University of Pittsburgh School of Medicine, researchers injected a llama named Wally (pictured) with a piece of the coronavirus’s spike protein and, after two months, the animal’s immune system produced nanobodies, which are several times smaller than human antibodies, against the virus

The nanobodies were many times more effective at neutralizing the virus and were able to save one million cells from becoming infected. Pictured: Lead author Dr Yufei Xiang holds a 3-D printed model of nanobodies (purple) on top of the SARS-CoV-2 spike protein (gray)

The nanobodies were many times more effective at neutralizing the virus and were able to save one million cells from becoming infected. Pictured: Lead author Dr Yufei Xiang holds a 3-D printed model of nanobodies (purple) on top of the SARS-CoV-2 spike protein (gray)

‘Nature is our best inventor,’ said senior author Dr Yi Shi, ad assistant professor of cell biology at the University of Pittsburgh School of Medicine.

‘The technology we developed surveys SARS-CoV-2 neutralizing nanobodies at an unprecedented scale, which allowed us to quickly discover thousands of nanobodies with unrivaled affinity and specificity.’

For the study, published in the journal Science, the team used a black llama named Wally to generate the antibodies. 

The team injected Wally with a piece of the coronavirus’s spike protein, which the pathogen uses to enter and infect human cells. 

After about two months, the animal’s immune system produced nanobodies against the virus.

Using a technique called mass spectometry, which looks at the mass-to-charge ratio of one or more molecules present in a sample, researchers identified the nanobodies in Wally’s blood that bound to the virus the strongest.

Next, to test their strength, they exposed the nanobodies to live coronavirus particles. 

Just a fraction of a nanogram of the nanobodies was able to neutralize enough virus to save one million cells from becoming infected.

What’s more, the team says these antibodies can sit at room temperature for six weeks, unlike other medications. 

The nanobodies can also be developed to use as an inhalable mist so the treatment is delivered straight to the lungs. 

Because the coronavirus is a respiratory virus, the nanobodies can find and latch onto it in the respiratory system before it caused any damage.

In contrast, traditional human antibodies require an IV, which dilutes the treatment, requiring a much larger dose and costing more money.

‘Nanobodies could potentially cost much less,’ said Shi. 

‘They’re ideal for addressing the urgency and magnitude of the current crisis.’

This is not the only study that has looked at llamas in hopes the animals could help curb the pandemic, which has led to more than 233,000 deaths in the US. 

Researchers from the University of Texas at Austin discovered an antibody produced by llamas that binds to proteins found on the surface of Severe Acute Respiratory Syndrome (SARS), a cousin of the new virus.

By engineering two copies of the antibody, they bound more effectively to the new virus’s spike proteins and essentially neutralized them.

The team says it hopes to develop a treatment that would be given to people immediately after becoming infected with COVID-19.  



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Canada

Manufacturer of synthetic COVID-19 antibodies reports positive results


WASHINGTON | Two American companies, Regeneron and Eli Lilly, on Wednesday published different and more or less conclusive results on their COVID-19 treatments based on synthetic antibodies, considered promising for patients at the onset of the disease.

• Read also: Remdesivir, used against COVID-19, has already grossed almost $ 900 million for Gilead

• Read also: Treatments for COVID-19: some progress, no panacea

• Read also: Synthetic Antibodies to Trump’s Rescue

Regeneron on the one hand said in a press release that trials on 524 patients had shown that its cocktail of so-called monoclonal antibodies, REGN-COV2, had reduced the viral load of patients, and the need for medical attention. or hospitalization, compared to patients who received a placebo.

This is the treatment that US President Donald Trump received in early October.

These results, which supplement precedents on 275 patients, have not yet been independently evaluated by a scientific journal.

The Eli Lilly group, which had previously published interim results in press releases, on Wednesday published results of the phase 2 trial of its own antibody treatment (LY-CoV555, also known as bamlanivimab) in the medical journal New England Journal of Medicine.

The data from this trial is mixed. A single dosage (2,800 mg) showed modest efficacy in outpatients with mild to moderate symptoms.

Both companies are supported by the US government.

Regeneron has received several contracts, including one for $ 450 million, to help manufacture large-scale doses in the United States. And the government on Wednesday announced it was purchasing 300,000 doses of Lilly’s treatment, but in a different strength (700 mg), for $ 375 million, with an option at $ 812.5 million for an additional 650,000 doses.

Both have filed applications for authorization with the United States Medicines Agency (FDA), with treatments today only available through clinical trials or case-by-case authorizations, like Mr. Trump benefited from it.



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Health

COVID-19 Antibodies Decline Over Time, Study Shows


A study of 365,000 people in England found evidence that coronavirus antibodies decline over a 3-month period.

The participants did three rounds of finger-prick tests at home between June 20 and Sept. 28, according to a news release from the Imperial College London. Rather than building up immunity, the number of people with antibodies fell from 6% at the start of the study to 4.4% at the end – a drop of about 26.5%, the release said.

The decline was highest among people 75 and older and lowest in people 18-24. Health care workers showed no decline in antibodies.

“This very large study has shown that the proportion of people with detectable antibodies is falling over time,” said Professor Helen Ward, one of the lead authors of the report. “We don’t yet know whether this will leave these people at risk of reinfection with the virus that causes COVID-19, but it is essential that everyone continues to follow guidance to reduce the risk to themselves and others.”

Researchers cautioned, however, that the study has limitation and that the same groups of people were not necessarily tested in each round, so there may be a chance that less infected people were tested in each round.

The findings are a blow to scientists who think herd immunity will eventually bring down the coronavirus.


Herd immunity occurs when a large part of a population becomes immune to a disease by developing antibodies, either by vaccination or by becoming infected.

While every single individual may not be immune, the group as a whole has protection. Researchers have said 50% to 67% of the population would need to be resistant before herd immunity kicks in and the infection rates start to go down.

Professor Paul Elliott, director of the Imperial College London program, emphasized that scientists still don’t know how much — if any — immunity is imparted by having COVID antibodies.

“Testing positive for antibodies does not mean you are immune to COVID-19,” he said. “It remains unclear what level of immunity antibodies provide, or for how long this immunity lasts. If someone tests positive for antibodies, they still need to follow national guidelines including social distancing measures, getting a swab test if they have symptoms and wearing face coverings where required.”



WebMD Health News


Sources

Imperial College London. “Declining prevalence of antibody positivity to SARS-CoV-2: a community study of 365,000 adults”

https://www.imperial.ac.uk/media/imperial-college/institute-of-global-health-innovation/MEDRXIV-2020-219725v1-Elliott.pdf

Imperial College London. “Coronavirus antibody prevalence falling in England, REACT study shows”

https://www.imperial.ac.uk/news/207333/coronavirus-antibody-prevalence-falling-england-react/

WebMD. “What Is Herd Immunity?”

https://www.webmd.com/lung/what-is-herd-immunity#1



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Health

Patients With Worst COVID May Be Key Plasma Donors


By Steven Reinberg
HealthDay Reporter


TUESDAY, Oct. 27, 2020 (HealthDay News) — Factors such as sex, age and severity of the disease may help identify COVID-19 survivors who have high levels of antibodies that can protect against the disease, a new study suggests.


“These were significant patient characteristics that not only predicted the amount of antibody but the quality of that antibody,” said lead author Sabra Klein, a professor in the Department of Molecular Microbiology and Immunology at Johns Hopkins Bloomberg School of Public Health in Baltimore.


Specifically, older men who have recovered after a hospital stay for COVID-19 may be good candidates for donating plasma for treating other infected patients, the study suggests.


Plasma trials are continuing, but doctors are unsure how to select COVID-19 survivors who are most likely to have strong antibody responses.


For the study, researchers tested the blood of 126 COVID-19 survivors and found many differences in their antibody levels and their antibodies’ ability to neutralize SARS-CoV-2. Factors linked with stronger antibody responses included being sick enough to be hospitalized, being older and being male.


“We know that the magnitude of antibody responses correlates with disease severity in other infectious diseases, such as active tuberculosis,” Klein said in a Hopkins news release.


The findings were recently published in the Journal of Clinical Investigation.



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Coronavirus COVID-19 Health UK

Covid: Antibodies ‘fall rapidly after infection’

Levels of protective antibodies in people wane “quite rapidly” after coronavirus infection, say researchers.

Antibodies are a key part of our immune defences and stop the virus from getting inside the body’s cells.

The Imperial College London team found the number of people testing positive for antibodies has fallen by 26% between June and September.

They say immunity appears to be fading and there is a risk of catching the virus multiple times.

More than 350,000 people in England have taken an antibody test as part of the REACT-2 study so far.

In the first round of testing, at the end of June and the beginning of July, about 60 in 1,000 people had detectable antibodies.

But in the latest set of tests, in September, only 44 per 1,000 people were positive.

It suggests the number of people with antibodies fell by more than a quarter between summer and autumn.

“Immunity is waning quite rapidly, we’re only three months after our first [round of tests] and we’re already showing a 26% decline in antibodies,” said Prof Helen Ward, one of the researchers.

The fall was greater in those over 65, compared with younger age groups, and in those without symptoms compared with those with full-blown Covid-19.

The number of healthcare workers with antibodies remained relatively high, which the researchers suggest may be due to regular exposure to the virus.

Antibody
image captionY-shaped antibodies stick to the surface of viruses to stop them infecting the body’s cells

Antibodies stick to the surface of the coronavirus to stop it invading our body’s cells, and attract the rest of the immune system.

Exactly what the antibody drop means for immunity is still uncertain. There are other parts of the immune system, such as T-cells, which may also play a role, directly killing infected host cells and calling to other immune cells to help out.

However, the researchers warn antibodies tend to be highly predictive of who is protected.

Prof Wendy Barclay said: “We can see the antibodies and we can see them declining and we know antibodies on their own are quite protective.

“On the balance of evidence, I would say it would look as if immunity declines away at the same rate as antibodies decline away, and that this is an indication of waning immunity.”

There are four other human coronaviruses, which we catch multiple times in our lives. They cause common cold symptoms and we can be reinfected every six to 12 months.

There have been very few confirmed cases of people getting Covid twice. However, the researchers warn this may be due to immunity only just starting to fade since the peak infection rates of March and April.

The hope is the second infection will be milder than the first, even if immunity does decline, as the body should have an “immune memory” of the first encounter and know how to fight back.

The researchers say their findings do not scupper hopes of a vaccine, which may prove more effective than a real infection.

One of the researchers, Prof Graham Cooke, said: “The big picture is after the first wave, the great majority of the country didn’t have evidence of protective immunity.

“The need for a vaccine is still very large, the data doesn’t change that.”

Professor Paul Elliott, director of the REACT-2 study, said it would be wrong to draw firm conclusions from the study about the impact of a vaccine.

He said: “The vaccine response may behave differently to the response to natural infection.”

But he said it was possible that some people might need follow-up booster doses of any vaccine that became available to top up fading immunity over time.

Commenting on the findings, Prof Jonathan Ball from the University of Nottingham said: “This study confirms suspicions that antibody responses – especially in vulnerable elderly populations – decrease over time.”

However, he said it was still important to get a better overall view of “what protective immunity looks like”.

Prof Eleanor Riley, from the University of Edinburgh, said it would be “premature” to assume immunity did not last, but “the data do lend weight to the concern that antibodies induced by natural infection may be short-lived, as is the case for other seasonal coronaviruses.”