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.

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.

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.

Many worldwide government leaders are not qualified to manage the handling of a pandemic like Covid-19, and many have made major mistakes for over a year now. We are not here to blame, and we understand that day-to-day government operations do not normally include management of an airborne infectious disease pandemic. So, we ask that, for the benefit of all people everywhere, governments follow these simple but effective guidelines in managing and then eradicating the Covid-19 pandemic. First of all, Join the 10 day simultaneous confinement recommended at 10days.us! Help make it happen and slow covid down immediately!

1) Most importantly, random testing should be done by region, as all other testing is skewed and biased. The only way to know the real rate of increase or decrease of positivity, or past infection, or of a specific mutation or variant in a population is through 100% random testing of the population group. Even a small sample size, if done properly, will give truer results than simply collecting data from those who get tested.

2) Covid only hospitals should be built (in the UK they call them Nightingale hospitals) and all covid patients should be moved there and treated there. This involves building living and sleeping areas on-site for the doctors and nurses who work at the covid hospitals. This will provide a great economy of money and resources, as well as protect existing regular hospitals (which will have a reduced operation and staff as some of their staff will have to move to the covid hospitals). Alternatively, some existing hospital facilities can be turned over 100% to treating covid patiens. Thus no mixing of covid patients and other hospitalized patients occurs and a major vector of transmission is eliminated.

Engineers and doctors say that air cleaning devices could play an important role in protecting your family from COVID-19 — especially as people start spending more time indoors as outdoor air temperatures fall in the Northern Hemisphere.

"It's a relatively easy way to get clean air in a place where people are in close contact," says Joseph Gardner Allen, an associate professor of exposure assessment science who directs the Healthy Buildings program at the Harvard T.H. Chan School of Public Health. "It's a simple plug and play solution in that area." (He bought one in March.)

With new attention on the role that aerosolized microdroplets could play in the spread of COVID-19, should you rush out to buy a portable air cleaner for home use?

The frustrating short answer is, "It depends."

It's accepted that the coronavirus can move in multiple ways, though less is understood about how each contributes to transmission of the disease. Those possible transmission methods include short-range airborne particles, ballistic droplets from coughing or sneezing, long-range airborne particles and contaminated surfaces.

Portable air cleaners can limit the spread of the virus via long-range airborne particles by capturing most of those particles in a HEPA filter and cleaning the air at a rate of up to six times per hour. In a typical home without an air cleaner, the air gets fully changed out about once every two hours through air leakage, often aided by mechanical ventilation systems in newer houses.

So, in the right circumstances, portable air cleaners offer an additional layer of protection.

If you're living by yourself and you don't have guests over, it's not going to add any protection (against COVID-19, anyway ... you may want one to combat cat dander or wildfire smoke).

Poor regulation of antibodies tests - that could indicate if someone has had coronavirus - could be putting the public at risk, doctors have warned.

The U.K. Royal College of Pathologists has written to the health secretary, calling for rules to be tightened on kits sold direct to consumers.

The letter warns they can "mislead the public and put individuals at risk".

No antibodies test has been officially approved for at-home use in the UK - but many different types are available.

It is still not known whether having antibodies will protect people from a second infection.

The doctors say the tests should not be used without "professional back-up", must "give the right result" and be "properly readable".

A Medicines and Healthcare products Regulatory Agency official said it had "worked collaboratively with cross-government agencies at pace to prevent non-compliant antibody test kits being placed into the UK market".

But Royal College of Pathologists president Prof Jo Martin said: "Currently, if you buy a test on the internet or you buy it in certain boutiques or shops, we can't guarantee that the quality of that is of an appropriate standard.

"We can't guarantee that the result will be easy to interpret or that it will be not misleading."

An analysis of 41 antibodies tests sold to the public in the UK, seen by the BBC's Newsnight programme before publication in the medical journal BMJ Open, found almost a third provided incomplete and inaccurate information.

A number claimed to offer "peace of mind".

But just 10% had made documents available to support their claims, academics from the Universities of Birmingham and Warwick found.

What information has been released about how kits were assessed shows most were tested on small numbers of patients only - just a few dozen, all of whom had been admitted to hospital.

People who have had Covid-19 Coronavirus often never feel completely healthy again. Many of us cannot exercise as well or as often, and many have persistent fatigue of varying degrees. Our lungs don't work as well, and our muscles feel sore for no reason. Sometimes there are bodily aches and pains, perhaps as a result of kidney damage. Often these problems still exist for 3, 4 or more months after testing negative after having the virus.

We ask that the world's governments and scientists and health organizations investigate the following:

1) Heat and Humidity for clearing Covid-19 from the lungs once infected. Many cultures and individuals believe that wet saunas and / or dry saunas help the lungs. We want studies to be done which test the recovery of Covid-19 positive individuals with both heat and humidity (a wet sauna) and heat alone (a dry saune). Do recovery times improve? Is lung damage reversed? Please help those suffering from lung damage by testing these possible treatments. Also, should Covid-19 recovered people work their lungs a lot with aerobic exercises like running, fast walking, etc? Is this a good thing to do after recovery? Can strenuous aerobic exercise for 45 to 60 minutes or more help lungs recover, and possibly reverse coronavirus lung damage?  People: please do NOT do this while you are infected. And please be aware that the course of an infection can wax and wane. Often people who are positive for Covid-19 will feel much better after a week or 10 days, return to their "normal" lives, and then feel even sicker than how they felt with the original onset of symptoms, for a week or two. Sometimes this "cycle" repeats again! You need your strength to recover, so it is not advised to do any strenuous exercise until you are clearly in the recovery phase, and stop sleeping for abnormally long periods of time.

Be aware that transmission of Covid-19, Coronavirus, from animals to other animals and transmission from animals to people, and from people to animas is almost certainly occuring.

It has been established that covid-19 can infect and kill dogs, cats, minks, and other species. We need testing to be done to determine whether or not infected animals can pass the coronavirus on to people (it is believed that they can transmit the coronavirus to people), whether people can pass the virus to their pets (this is probably how pets become infected in the first place), and whether pets can pass the Covid-19 virus on to other pets of the same species and other pets and animals of different species.

Until such time as more is known about this; we must recommend that people take precautions with their pets; stop "kissing" their pets (this is never really a good idea, and no saliva should ever be exchanged between people and other species, including dogs and cats - please make your children aware of this), and stop getting their faces close to those of their pets so as to share the same air.

Please do not abandon pets because of this possibliity or probability of transmission; rather have pets with breathing difficulties tested, and enforce some social distancing, if necessary if people or pets in a household are infected. Some infecetd people who self-isolate do not stay away from their pets, and this is an error which can potentially be fatal for your beloved pets, so please include pets when isolating. The period of contagion does not, it is believed, last for more than 2 to 3 weeks, so any social distancing that is done between people and their pets is for a short period of time only.

Please respect these guidelines.

People who have had Covid-19 Coronavirus often never feel completely healthy again. Many of us cannot exercise as well or as often, and many have persistent fatigue of varying degrees. Our lungs don't work as well, and our muscles feel sore for no reason. Sometimes there are bodily aches and pains, perhaps as a result of kidney damage. Often these problems still exist for 3, 4 or more months after testing negative after having the virus.

We ask that the world's governments and scientists and health organizations investigate the following:

Be aware that a high temperature is NOT an accurate check for Coronavirus or Covid-19. Many people testing positive for Covid-19 will never have a higher than normal temperature. A presistant cough, difficulty breathing, combined with sore muscles and abnormal persistent fatigue is a more reliable check - but these also will neither show up in milder cases, nor in many asymptomatic cases, nor in cases of healthy people under the age of 40 or 50.

The only sure way to test if you have coronavirus, or Covid-19, is to be tested. Tests are available that determine present infections, using a nosal or throat swab, or saliva; and other tests are available which show past infections, using blood.

We advocate that every person be given one free blood test, and one free swab or saliva test if they have persistent symptoms.

Throughout the pandemic, health officials have been urging us to keep our hands clean. Why? To kill particles of coronavirus to prevent it from spreading.

Hand sanitisers are one way to do so, but not all of them are effective, as the US Food and Drug Administration (FDA) has repeatedly warned.

This week, the FDA expanded the list of products it advises people not to use to about 100 brands and 150 varieties.

Of the new products added to the list, 20 were sanitisers that didn’t contain enough alcohol to be effective.

To kill the virus, hand sanitisers must contain a sufficient amount of alcohol, at least 60% ethanol or 70% isopropanol, according to the Centers for Disease Control and Prevention (CDC). They must also be safe to use on the skin.

While most children who catch the coronavirus have either no symptoms or mild ones, they are still at risk of developing "severe" symptoms requiring admission to an intensive care unit, the Centers for Disease Control and Prevention said in a new report released Friday.

Despite persistent rumors that children are "almost immune" from the virus, the analysis of 576 children hospitalized for the virus across 14 states found that one out of three was admitted to the ICU — similar to the rate among adults. Almost 1 in 5 of those were infants younger than 3 months. The most common symptoms included fever and chills, inability to eat, nausea and vomiting. The CDC concluded that it's crucial to continue prevention efforts wherever children gather, specifically citing schools and child care centers.