Category: COVID19

A sleeping aid hormone sold over-the-counter could be a useful treatment for coronavirus.

Melatonin has been identified as a potential drug for the treatment of coronavirus disease.

Melatonin is a natural hormone produced in the brain to control our sleep-wake cycle.

It is readily available and sold as a sleep-aid medicine without a prescription.

Due to increasing levels of COVID-19, scientists are looking for a new use for drugs that are already approved.

In an attempt to identify a low cost and effective treatment for the novel coronavirus, Lerner Research Institute researchers identified melatonin as a promising therapy for COVID-19.

Moreover, when researchers analysed patients’ data from a Cleveland Clinic, they found that those on melatonin had a 28 percent lower risk of testing positive for Covid-19.

The risk of testing positive for SARS-CoV-2 virus among African Americans was reduced by 52 percent.

Dr Feixiong Cheng, the study’s lead author, said:

“It is very important to note these findings do not suggest people should start to take melatonin without consulting their physician.

Large-scale observational studies and randomized controlled trials are critical to validate the clinical benefit of melatonin for patients with COVID-19, but we are excited about the associations put forth in this study and the opportunity to further explore them.”

The method was based on the identification of the causes and symptoms of COVID-19 and other illnesses.

For instance, they noticed that proteins related to respiratory distress syndrome (RDS) and sepsis were hugely connected with SARS-CoV-2 proteins.

RDS is a common breathing disorder and sepsis is an illness caused by the body’s severe response to an infection.

These two conditions are major causes of death in COVID-19 patients.

Dr Cheng said:

“This signals to us that that a drug already approved to treat these respiratory conditions may have some utility in also treating COVID-19 by acting on those shared biological targets.”

The team found that pulmonary conditions such as pulmonary fibrosis and chronic obstructive pulmonary disease, neurological problems such as Attention deficit hyperactivity disorder (ADHD) and depression, and autoimmune disorders such as inflammatory bowel disease all showed a link to SARS-CoV-2 genes/proteins.

This led the team to single out 34 existing drugs as COVID-19 treatment candidates and melatonin was the most successful one.

Dr Cheng explained:

“Recent studies suggest that COVID-19 is a systematic disease impacting multiple cell types, tissues and organs, so knowledge of the complex interplays between the virus and other diseases is key to understanding COVID-19-related complications and identifying repurposable drugs.

Our study provides a powerful, integrative network medicine strategy to predict disease manifestations associated with COVID-19 and facilitate the search for an effective treatment.”

The study was published in the journal PLOS Biology (Zhou et al., 2020).

The percentage of people who show strong antibody responses for many months after infection with the COVID-19 virus.

Most individuals infected with mild-to-moderate COVID-19 have the ability to neutralize the SARS-CoV-2 virus that is responsible.

Contrary to the media panic suggesting that antibodies against the coronavirus fade swiftly, a new Mount Sinai study proves otherwise.

In fact, more than 90 percent of recovered patients produce a strong antibody response lasting for a long time after infection.

Professor Florian Krammer, the study’s senior author, said:

“While some reports have come out saying antibodies to this virus go away quickly, we have found just the opposite—that more than 90 percent of people who were mildly or moderately ill produce an antibody response strong enough to neutralize the virus, and the response is maintained for many months.

Uncovering the robustness of the antibody response to SARS-CoV-2, including its longevity and neutralizing effects, is critically important to enabling us to effectively monitor seroprevalence in communities and to determining the duration and levels of antibody that protect us from reinfection.

This is essential for effective vaccine development.”

The findings are based on data from more than 30,000 COVID-19 recovered patients who were tracked from March to October 2020.

The research used a very sensitive and specific test which made it unlikely to generate either a false positive or a false negative.

This specific antibody test shows the amount (titer) of antibodies against SARS-CoV-2 produced by a person.

Professor Carlos Cordon-Cardo, study co-author, said:

“Our microbiology colleagues generated great science and tools that were brought from the research lab into the clinical laboratory, where we were able to implement robust and compliant diagnostic tests at an unprecedented pace.

The tireless efforts of so many have enabled us to uncover knowledge that can help inform COVID-19 policy and aid in vaccine development.”

SARS-CoV-2 has different proteins able to reproduce and infect our cells and the spike protein (S-protein) is the main part that the virus uses to attach itself to human cells.

Therefore, key for neutralizing antibodies as well as vaccines is to target the S-protein.

The other important issue is how long the antibody response to the S-protein lasts.

To find out the antibody longevity, the researchers recruited a number of recovered patients to donate their blood for convalescent plasma therapy.

The antibody levels of the plasma donors were measured at 3 months and 5 months afterwards.

They noticed that after 5 months a reasonable level of antibodies was achieved by most people.

A study by Ripperger et al., has also shown similar results.

Dr Ania Wajnberg, the study’s first author, explained:

“The serum antibody titer we measured in individuals initially were likely produced by plasmablasts, cells that act as first responders to an invading virus and come together to produce initial bouts of antibodies whose strength soon wanes.

The sustained antibody levels that we subsequently observed are likely produced by long-lived plasma cells in the bone marrow.

This is similar to what we see in other viruses and likely means they are here to stay. We will continue to follow this group over time to see if these levels remain stable as we suspect and hope they will.”

The study was published in the journal Science (Wajnberg et al., 2020).

Those who say SARS-CoV-2 antibodies only provide short-term immunity are missing the complete picture.

The novel coronavirus has been the centre of attention and a central question is whether, and for how long after infection people will be immune to the disease.

To answer this question scientists have examined the antibody production of about 6,000 individuals.

Their results show that immunity lasts for many months after recovery from COVID-19 infection.

Dr Deepta Bhattacharya, the study’s senior author, said:

“Many concerns have been expressed about immunity against COVID-19 not lasting.

We clearly see high-quality antibodies still being produced five to seven months after SARS-CoV-2 infection.”

After cells are infected by the virus our immune system uses short-lived plasma cells developed from B cells, a type of white blood cell.

These cells produce antibodies to kill the virus and the antibodies are the ones that are detected in blood tests for two weeks after infection.

Thereafter the next phase of the immune response starts which involves the production of long-lived plasma cells.

These cells generate a type of antibody that protects us from reinfection for a longer period.

The research team were able to detect high enough amounts of these antibodies in recovered patients seven months later.

Dr Michael Dakestudy, study co-author, said

“Whether antibodies provide lasting protection against SARS-CoV-2 has been one of the most difficult questions to answer.

This research not only has given us the ability to accurately test for antibodies against COVID-19, but also has armed us with the knowledge that lasting immunity is a reality.”

Previously, researchers didn’t have enough data so they thought after infection antibody levels were rapidly reduced and so immunity must be short-term.

Dr Bhattacharya points out that these studies concentrated on short-lived plasma cells and didn’t look at the high-affinity antibodies produced by long-lived plasma cells.

She said:

“The latest time-points we tracked in infected individuals were past seven months, so that is the longest period of time we can confirm immunity lasts.

That said, we know that people who were infected with the first SARS coronavirus, which is the most similar virus to SARS-CoV-2, are still seeing immunity 17 years after infection.

If SARS-CoV-2 is anything like the first one, we expect antibodies to last at least two years, and it would be unlikely for anything much shorter.”

The team developed one of the most precise COVID-19 antibody tests that is able to detect high-affinity antibodies even after a long period of infection.

The test uses two specific regions (S1 and S2) of the SARS-CoV-2 virus.

Professor Janko Nikolich-Zugich, the study’s senior author, said:

“When we began, the first test we developed was 99% accurate for measuring antibodies in one part of the virus.

We decided to confirm, and hopefully improve, that accuracy level by looking at another part of the virus that makes antibodies independent of the first location.

We then validated that test, knowing some people will make antibodies more consistently for one part of the virus than the other. We put the two tests together, and only people who show antibody production for both parts of the test are determined to be positive.”

The study was published in the journal Immunity (Ripperger et al., 2020).

Coronavirus vaccine goes to phase 3 trial enrolling 30,000 people in the US.

Early tests of the Oxford coronavirus vaccine show that it creates a powerful immune response through antibodies and T-cells and appears safe.

The vaccine candidate causes the common cold in chimpanzees but appears to be harmless to humans.

The researchers engineered a modified version to resemble the surface of SARS-CoV-2, which has a ‘spike’ protein.

The coronavirus spikes attach themselves to human cells, then the virus enters the cells and starts to reproduce more viruses.

The resemblance of the vaccine to the coronavirus will prepare our immune system to fight it off efficiently.

The vaccine could be very effective since it causes both antibodies and T-cells to respond.

The phase two trial shows that the T-cell response occurred in 14 days and the antibody response was within 28 days of vaccination.

Antibodies and T-cells are both crucial parts of our immune defence.

The antibody’s job is to offset the coronavirus by sticking to them and stopping them from infecting cells.

T-cells are a type of white blood cell which are able to kill infected cells with the SARS-CoV-2 virus.

Professor Andrew Pollard, study’s co-author, said:

“We’re really pleased with the results published today as we’re seeing both neutralising antibodies and T-cells.

They’re extremely promising and we believe the type of response that may be associated with protection.

But the key question everyone wants to know is does the vaccine work, does it offer protection… and we’re in a waiting game.”

Phase I/II trial involved 1,077 healthy adult volunteers who received the vaccine candidate developed by Oxford University and licensed to AstraZeneca.

About 90 percent of participants produced neutralising antibodies after one injection and only 10 subjects needed a second dose to develop neutralising activity against SARS-CoV-2 infection.

Subjects who took the vaccine didn’t suffer from any serious side-effects but 70 percent of them had either headache or fever.

Professor Pollard said:

“We saw the strongest immune response in the 10 participants who received two doses of the vaccine, indicating that this might be a good strategy for vaccination.”

The aim of vaccination is either to stop people getting sick or at least minimise coronavirus symptoms.

Phase 3 trials will confirm if the vaccine can definitely protect people against COVID-19.

At this stage 10,000 people will take part in the UK, 30,000 in the US, 5,000 in Brazil, and 2,000 in South Africa to make sure it is a safe and effective vaccine.

Mr Mene Pangalos from AstraZeneca, said:

“We are encouraged by the Phase I/II interim data showing AZD1222 was capable of generating a rapid antibody and T-cell response against SARS-CoV-2.

While there is more work to be done, today’s data increases our confidence that the vaccine will work and allows us to continue our plans to manufacture the vaccine at scale for broad and equitable access around the world.”

The study was published in The Lancet (Folegatti et al., 2020).

Children are unlikely to become infected with COVID-19, or pass it on to adults.

Schools are safe to reopen in fall as children are unlikely to spread COVID-19 to each other or infect adults.

Dr Benjamin Lee and Dr William Raszka, the authors of an article called “COVID-19 Transmission and Children: The Child Is Not to Blame” urge governments to reopen schools.

Their report is based on mounting evidence that children play a minor role in the transmission of COVID-19.

Evidence show that children under 16-years-old rarely spread the coronavirus disease to others, therefore they play an insignificant part in COVID-19 outbreaks.

The reasons that children are less likely to become infected and also to be less infectious to adults or other children are not clear.

Dr William Raszka said:

“With influenza, children are well-known spreaders of the disease.

That’s been one of the major surprises, that children do not spread or transmit coronavirus as efficiently.

It’s sort of mysterious why younger children seem to be much less frequently infected and generally speaking have much less severe disease, and why they don’t transmit as often.”

However, one possibility is that children have mild symptoms such as weaker and fewer coughs consequently they release fewer infectious particles into their surroundings.

Also, they don’t appear to have prolonged conversations with adults or other children as adults tend to have.

Moreover, during the lockdown period and social distancing, children have learned to have less direct contact like hugging and touching.

All these may be reasons why children with COVID-19 are not as active in spreading the disease as much as other germs like influenza.

Dr William Raszka said:

“Generally, the younger you are, then the less likely you are to transmit to other children or adults.

With precautions, schools should reopen.”

Dr Amesh Adalja from the Johns Hopkins Center for Health Security, commented:

“We have seen schools open in places like Denmark and Finland without a problem, and day care centers have been open for essential workers throughout the pandemic.

It will be important for schools to develop a plan for dealing with cases and allowing for social distancing, but we are causing harm to a whole generation of students who are not able to be educated adequately.”

Research on families in Switzerland found that adults spread COVID-19 and infect children.

Children pass the coronavirus to older relatives less than eight percent of the time.

Dr Arnaud L’Huillier, a pediatric infectious disease specialist at Geneva University Hospitals said:

“Reopening schools does not seem to be a public health issue when compared to reopening restaurants, bars and shops.”

A study of 68 Chinese children with COVID-19 who were admitted to a hospital in China found that 96% of these children were infected by adults from their households.

The other paediatric evidence is a French study which found a boy with COVID-19 exposed to over 80 classmates but didn’t infect any of them.

In an Australian study, nine infected students were exposed to 863 students and staff at over 15 schools.

Only two people got infected with COVID-19 and one was caused by an adult who spread the disease to the child.

Dr William Raszka said:

“The data are striking.

The key takeaway is that children are not driving the pandemic.

After six months, we have a wealth of accumulating data showing that children are less likely to become infected and seem less infectious; it is congregating adults who aren’t following safety protocols who are responsible for driving the upward curve.”

The study was published in the journal Pediatrics (Lee & Raszka, 2020).

Can social distancing work or there are better ways to lower COVID-19 spread?

Coronavirus can travel further than 10 meters in the air when infected people breathe out the droplets, cough, sneeze, or even just talk.

The virus droplet are very small and so they can spread further than the recent social distancing measurements.

Although this looks frightening, the virus has to overcome many obstacles in order to infect a person.

Viruses are known to travel by aerosol but in fact plenty of them are damaged in the air, therefore only a small percentage of viruses in exhaled breath remain infectious (Milton et al., 2013).

An experimental study by Doremalen et al. (2020) found that once the SARS-CoV-2 virus has left the body it remains active for 3 hours, while another study suggests 16 hours (Fears et al., 2020).

These studies were done in the lab and are not true reflections of human exhaled conditions and it is still the case that the virus declines in a short period of time.

The other factor is that the chance of inhaling airborne virus droplets is higher in crowded places or close contact less than 2 meters from an infected person.

A new petition signed by 239 scientists points out that the virus aerosols can travel further than the current social distancing rules, suggesting measures should be taken in preventing the airborne transmission of Covid-19.

Professor Lidia Morawska who led the signatories, said:

“Studies by the signatories and other scientists have demonstrated beyond any reasonable doubt that viruses are exhaled in microdroplets small enough to remain aloft in the air and pose a risk of exposure beyond 1 to 2m by an infected person.

At typical indoor air velocities, a 5-micron droplet will travel tens of meters, much greater than the scale of a typical room while settling from a height of 1.5m above the floor.”

Researchers suggest that the risk of Covid-19 airborne transmission is nearly 19 times higher indoors than in open-air places (Nishiura et al., 2020).

Many indoor places lack decent ventilation and the air becomes stagnant, increasing the infection risk.

The signatories highlight some practical measures as previously suggested by other studies including (Kumar & Morawska, 2020):

• Install ample and proper building ventilation to provide clean outdoor air and filter air, especially in hospitals, public buildings, care homes, workplace, and schools.

• Add airborne infection controls, like high efficiency air filtration, local exhaust, and germicidal ultraviolet lights.

• Overcrowding in public buildings and on public transport should be avoided.

The authors write:

“These are practical and can be easily implemented and many are not costly.

For example, simple steps such as opening both doors and windows can dramatically increase air flow rates in many buildings.

Numerous health authorities currently focus on hand-washing, maintaining social distancing, and droplet precautions.

Hand-washing and social distancing are appropriate, but it is view, insufficient to provide protection from virus-carrying respiratory microdroplets released into the air by infected people.”

“It is Time to Address Airborne Transmission of COVID-19” is published in the journal of Clinical Infectious Diseases (Morawska et al., 2020).

Public immunity to coronavirus disease is way above what antibody tests have shown.

More people have higher immunity to COVID-19 than suggested by antibody testing.

People with mild symptoms or those showing no symptoms of coronavirus seem to have T-cell-mediated immunity against COVID-19 infection.

Experts say this means that the levels of public immunity to the new coronavirus is greater than found in antibody tests.

Cell-mediated immunity is a type of immune responses in which antibodies are not involved.

T-cells are a type of white blood cell and part of the adaptive immune system.

Killer T-cells will destroy the virus while the other type, which are T helper cells, would organise the attack.

Dr Marcus Buggert, the study’s co-author, said:

“T cells are a type of white blood cells that are specialized in recognizing virus-infected cells, and are an essential part of the immune system.

Advanced analyses have now enabled us to map in detail the T-cell response during and after a COVID-19 infection.

Our results indicate that roughly twice as many people have developed T-cell immunity compared with those who we can detect antibodies in.”

The study ran immunological analyses on a group of people who had either mild symptoms or who were showing no signs of coronavirus infection.

Some of participants were a relative of COVID-19 patients who were exposed to them but showing no symptoms afterwards.

These asymptomatic family members, after spending their holiday in the Alps in March, had returned to Stockholm.

The research team were continuously monitoring and running tests on the patients and their families since they had the disease.

Dr Soo Aleman, the study’s senior author, said:

“One interesting observation was that it wasn’t just individuals with verified COVID-19 who showed T-cell immunity but also many of their exposed asymptomatic family members.

Moreover, roughly 30 percent of the blood donors who’d given blood in May 2020 had COVID-19-specific T cells, a figure that’s much higher than previous antibody tests have shown.”

Patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) developed a robust T-cell response and antibody production.

It was more difficult to notice antibody responses in those individuals with mild symptoms, nevertheless many showed a strong T-cell activation.

Professor Hans-Gustaf Ljunggren, study co-author, said:

“Our results indicate that public immunity to COVID-19 is probably significantly higher than antibody tests have suggested.

If this is the case, it is of course very good news from a public health perspective.”

Carrying out COVID-19 antibody tests is much easier than T-cells analysis as it must be done in a specialised laboratory in contrast to a home test kit and drive-through or walk-through test sites.

The study was published in bioRxiv (Sekine et al., 2020).