Discover Top Posts Tagged with #human coronaviruses

Reports suggest timeframe between recovery and reinfection ‘relatively short’ for those who contracted virus twice

Government science advisers have warned that reinfections with Covid-19 are “to be expected” as the virus spreads, based on what is known about people’s immunity to other coronaviruses that cause the common cold.

Researchers on the Covid-19 Genomics UK Consortium said it was unclear at what point people who had recovered from the virus became vulnerable to reinfection, but cited emerging reports of second infections that suggested the timeframe was “relatively short”.

There are seven types of coronavirus that infect humans, the deadliest being Sars, Mers and Sars-Cov-2 – the virus that causes Covid-19. The four others, which are in general circulation, cause common colds and can reinfect people six months after they have fought off the same virus.

The paper, released with a batch of Sage documents on Friday, suggests that large-scale genomic surveillance of the virus from positive test swabs could help identify cases of reinfection in the UK, but that such a system would require people to understand that once they have had Covid-19 they can be reinfected, and should get tested again if they develop symptoms.

Sadly, the warning comes from scientists but the government no longer seems to be “following the science,” as evidenced by its ignoring Sage’s lockdown advice in September.

#uk #covid19 pandemic #covid19 reinfections #human coronaviruses

One year after a coronavirus infection, and maybe even earlier, a person can become infected with the same virus again, Amsterdam UMC researchers concluded based on research into the four known and harmless seasonal coronaviruses. This probably also applies to the novel coronavirus SARS-CoV-2, the researchers conclude.

The researchers looked at blood samples from a group of healthy people, who had blood drawn every three to six months since the 1980s, checking for antibodies against the seasonal coronaviruses. In this way they could track back when a corona infection and re-infection with the same virus happened. They found that the duration of immunity was "alarmingly short", with reinfection regularly occurring after one year, and in some cases more quickly. This applies to all four seasonal coronaviruses.

"Precisely because the viruses differ greatly and we found the same result for all viruses, we think that this is a common property of all coronaviruses," researcher Arthur Edridge said. "This means that the immunity is also short-lived for the new coronavirus SARS-CoV-2."

What I said in April:

The bad news is with other coronaviruses like SARS or the common colds any immunity lasts only six months. If the same applies to Covid-19 building up herd immunity is impossible absent a vaccine which is the way most herd immunity has been achieved in the modern era. (02/04/20)

and

In the Netherlands blood donations are tested for antibodies against covid-19. So far they have also found 3% of people have antibodies. Since antibodies against the SARS and MERS coronaviruses only last 6 months it’s likely that those for covid-19 do the same and even the 3% will not have immunity after 6 months. This remains to be seen but seems likely. (17/04/20)

#netherlands #covid19 research #immunity #SARS-CoV-2 #human coronaviruses #seasonal coronaviruses #health

New research suggests that exposure to other coronaviruses that cause the common cold could help develop antibodies against the SARS-CoV-2 virus

After months of uncertainty and grim headlines, some scientists are hesitantly recognizing what could be good news. During the first weeks of the Covid-19 pandemic, it was estimated that around 60% of the population would need to be exposed to the coronavirus to achieve herd immunity, which occurs when a high percentage of the community is immune to a disease.

A large-scale antibody study in Spain found that around 5% of the population had contracted the coronavirus, with significant differences between the regions – in the Soria province, the figure was more than 14%, compared to 1.2% in Cádiz. The hope of achieving herd immunity seemed like a long shot. But as time passed, a growing amount of research began to suggest that more people are protected against the coronavirus, or at least its most serious versions, than the antibody studies indicated. Experts, however, do not want this news to be used as an excuse for the relaxation of coronavirus safety measures.

“We have been living with coronaviruses for a very long time. Most of them cause minor respiratory problems [like the common cold], while others are more serious, like SARS and MERS,” explains Juan Pablo Horcajada, the head of infectious diseases at the Mar Hospital in Barcelona. Four viruses in the coronavirus family cause around 25% of colds, and “it is well known that when there is an infection from a virus of the same family there could be a cross-reaction and the immune system could develop antibodies similar to the ones that neutralized the other virus,” he explains. “What we don’t know yet is if these antibodies can offer protection and if so, to what extent.”

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It casts doubt over the practicality of introducing "immunity passports", which some governments want to issue to COVID-19 survivors.

Immunity to reinfection from human coronaviruses may last only last six months, according to a study from the University of Amsterdam.

It casts doubt over the practicality of introducing "immunity passports", which some governments want to issue to COVID-19 survivors on the assumption they can't be reinfected and are free to help the economy get back on its feet.

The study monitored 10 men over 35 years to determine antibody levels following infection for any of the four seasonal human coronaviruses.

These men, then aged 27 to 40-year old, were tested at either three or six months intervals.

Researchers found that there was an "alarmingly short duration of protective immunity to coronaviruses" with scientists noting "frequent reinfections at 12 months post-infection and substantial reduction in antibody levels as soon as 6 months post-infection".

They stressed that the four strains of human coronaviruses are "biologically dissimilar" and "have little in common, apart from causing the common cold".

"Still, they all seem to induce a short-lasting immunity with rapid loss of antibodies. This may well be a general denominator for human coronaviruses.

"If SARS-CoV-2 will behave like a seasonal coronavirus in the future, a similar pattern may be expected," they went on.

Sweden might have to rethink it’s lack of lockdown.

#covid-19 #human coronaviruses #common cold #immunity #antibody response #antibody levels #immunity passports

What is Coronavirus - All about Coronavirus

What is Coronavirus – All about Coronavirus

Coronaviruses are types of viruses that typically affect the respiratory tracts of birds and mammals, including humans. Doctors associate them with the common cold, bronchitis, pneumonia, severe acute respiratory syndrome (SARS), and COVID-19. They can also affect the gut.

These viruses are typically to blame for common colds over serious diseases. However, coronaviruses also are behind some…

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LJI scientists identify potential targets for immune responses to novel coronavirus

LA JOLLA, CA—Within two months, SARS-CoV-2, a previously unknown coronavirus, has raced around globe, infecting over a 100,000 people with numbers continuing to rise quickly. Effective countermeasures require helpful tools to monitor viral spread and understand how the immune system responds to the virus.

Publishing in the March 16, 2020, online issue of Host, Cell and Microbe, a team of…

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What does self-quarantine mean?

As people wrestle with spring travel, many may choose – or be asked – to self-quarantine for a period of time to help deter the spread of COVID-19.

Isolation requires sick people to be separated from those who are not sick, while quarantine restricts the movement of people who are exposed to a contagious disease to monitor if they become sick, according to Luis Ostrosky, MD, professor of…

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How to prepare in the event of a pandemic

As COVID-19, also known as coronavirus, becomes more prevalent around the world, University of Alabama at Birmingham experts share tips to help you prepare yourself, your family and your home should the virus continue to gain momentum.

Photo by Pixabay on Pexels.com

What is COVID-19?

Human coronaviruses are the second most common cause of colds and generally cause mild to moderate…

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