Coronavirus: Oxford Vaccine Triggers Strong Immune Response

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

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 Unlikely To Spread COVID-19, Studies Find

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

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 Prevent Spread Of COVID-19?

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

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 COVID-19 Is Much Higher Than Thought

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

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).

How To Avoid A Second Wave Of COVID-19 Infections

It is possible to avoid a second wave of Covid-19 infections by following these interventions.

It is possible to avoid a second wave of Covid-19 infections by following these interventions.

Some are concerned that by easing lockdown restrictions countries will face a new wave of infections.

However, according to a new modelling study, this can be averted by simple measures.

Although there is no indication of a COVID-19 epidemic coming in waves, being sceptical may help avoid a national crisis.

People’s conduct has a serious effect on averting potential spikes or a second wave of coronavirus infections.

Simple interventions such as hand hygiene, social distancing, and wearing a face mask in crowded and enclosed public places could expel the idea of lockdowns in future.

This modelling study also shows that lockdowns should stay in place for two months to reach a peak of COVID-19 infections and then restrictions must be lifted gradually to lower a second wave risk.

Countries that forced a strict lockdown to reduce the SARS-CoV-2 transmission are now easing restrictions.

However, the process is sensitive as there is a fine line between saving the economy and fear of a second wave which might crush health care systems.

Professor Xavier Rodó, the study’s lead author, said:

“The problem is that assessing this risk is difficult, given the lack of reliable information on the actual number of people infected or the extent of immunity developed among the population.”

The projection model was based on splitting the population into seven scenarios: susceptible, quarantined, exposed, infectious not detected, reported infectious and confined, recovered, and dead.

Professor Rodó said:

“Our model is different because it considers the return of confined people to the susceptible population to estimate the effect of deconfinement, and it includes people’s behaviors and risk perception as modulating factors.”

Dr Leonardo López, the study’s first author, said:

“This model can be particularly useful for countries where the peak of cases has not yet been reached, such as those in the Southern hemisphere.

It would allow to evaluate control policies and minimize the number of cases and fatalities caused by the virus.”

The benefits of hand washing and other interventions such as social distancing have been already shown.

This study aimed to measure these behavioural interventions as infection prevention and control plans.

Their results show that as opposed to hasty deconfinement, gradually allowing life to come back to normal will reduce the infections rate and number of deaths.

Professor Rodó said:

“If we manage to reduce transmission rate by 30% through the use of face masks, hand hygiene and social distancing, we can considerably reduce the magnitude of the next wave.

Reducing transmission rate by 50% could avoid it completely.”

The results also show that even if countries don’t use coronavirus test and trace services, social empowerment like hand hygiene, social distancing, and wearing a face mask, is pivotal in preventing the spread of viruses.

Moreover, simulation results show that the longer people are immune from the disease the longer between each spike of the infection.

The study was published in Nature Human Behaviour (López et al., 2020).

The Real Number Of COVID-19 Cases In The US

The COVID-19 infection rate is 80 times higher than previously thought.

The COVID-19 infection rate is 80 times higher than previously thought.

Epidemiologists think that coronavirus numbers are being under-counted as a result of asymptomatic individuals, failure to detect early cases, and testing issues.

A study now reveals that the number of early COVID-19 cases in the United States could be 80 times higher and doubling almost twice as quickly as initially thought.

They used the Centers for Disease Control and Prevention’s influenza-like illnesses (ILI) surveillance data in order to detect symptomatic cases for COVID-19 infection.

Dr Justin Silverman, the study’s first author, said:

“We analyzed each state’s ILI cases to estimate the number that could not be attributed to influenza and were in excess of seasonal baseline levels.

When you subtract these out, you’re left with what we’re calling excess ILI—cases that can’t be explained by either influenza or the typical seasonal variation of respiratory pathogens.”

The exaggerated rates for influenza-like illnesses was absolutely associated with the coronavirus transmission across the states.

Dr Silverman said:

“This suggests that ILI data is capturing COVID cases, and there appears to be a much greater undiagnosed population than originally thought.”

The excess number of ILI cases agrees with over 8.7 million new cases in three weeks in March 2020, whereas officials reported 100,000 cases for the same period of time.

Dr Silverman said:

“At first I couldn’t believe our estimates were correct.

But we realized that deaths across the U.S. had been doubling every three days and that our estimate of the infection rate was consistent with three-day doubling since the first observed case was reported in Washington state on January 15.”

Then they used the same process to measure rates of COVID-19 infection state by state.

The results showed that infection rates were much greater than originally recorded but near to those figures found after antibody tests were used in every state.

For instance, the researchers’ model shows that by the end of March about 9 percent of New York’s population was infected but after using antibody tests in the state the infection rate increased to 13.9 percent — in other word 2.7 million New Yorkers could have tested positive.

The peak of ILI numbers seems to be in the middle of March since less patients with mild symptoms needed treatment.

Also from this period all states put public health interventions in place that reduced reduced the transmission rate.

By the end of March more than half of US states had imposed stay-at-home orders or lockdowns.

Dr Silverman said:

“Our results suggest that the overwhelming effects of COVID-19 may have less to do with the virus’ lethality and more to do with how quickly it was able to spread through communities initially.

A lower fatality rate coupled with a higher prevalence of disease and rapid growth of regional epidemics provides an alternative explanation of the large number of deaths and overcrowding of hospitals we have seen in certain areas of the world.”

The study was published in Science Translational Medicine (Silverman  et al., 2020).

The Type Of Light That Kills COVID-19

An indoor lamp that destroys coronaviruses in the air but is safe for humans.

An indoor lamp that destroys coronaviruses in the air but is safe for humans.

UVC is an ultraviolet light which rapidly kills bacteria and viruses but is safe for use in outdoor and indoor environments.

A study has found that far-UVC light has the ability to wipe out 99.9 percent of airborne coronaviruses.

Airborne transmission refers to the presence of pathogens in small droplets that are approximately less than 10μm in diameter.

An infected person — through coughing, sneezing, or speech –produces tiny droplets containing viral particles which are infectious for hours.

Viral transmission can be either through contact by contaminated hands, touching contaminated surfaces, or by breathing the viral particles in the air (aerosols).

The possibility of SARS-CoV-2 infection via aerosols increases when an environment is poorly ventilated.

Researchers suggest that exposure to a specific ultraviolet light wavelength kills 99.9 percent of coronaviruses remaining in airborne droplets.

Professor David Brenner, the study’s lead author, said:

“Based on our results, continuous airborne disinfection with far-UVC light at the current regulatory limit could greatly reduce the level of airborne virus in indoor environments occupied by people.”

Unoccupied places including empty subway cars or empty hospital rooms, can be disinfected by conventional germicidal UVC light at 254 nm wavelength, but exposure to these lamps is dangerous to human health and can cause skin cancers.

Researchers examined different UV lamps to see which length does not cause any harm to humans and so can be used for disinfecting pathogens in occupied indoor places all the time.

Far-UVC light at wavelengths from 207 to 222 nm has been known to destroy airborne influenza viruses.

They noticed that far-UVC light at 222 nm kills airborne seasonal coronaviruses that are similar in structure to the SARS-CoV-2 virus responsible for COVID-19 infections.

The lamp doesn’t cause any harm to human eyes and skin because it can’t enter the tear film of the eye or the outer layer of skin made of dead cells.

In short, this type of light can’t reach any living cells in the human body and therefore can’t damage them.

In this study, the aerosols containing the coronavirus flowed in front of a far-UVC lamp.

A very low exposure to the lamp was enough to completely destroyed them.

It appear that an eight-minute exposure to far-UVC light would kill 90 percent of SARS-CoV-2, in 11 minutes the rate will increase to 95 percent, in 16 minutes to 99 percent, and in 25 minutes 99.9 percent of them were dead.

Professor Brenner said:

“Far-UVC light doesn’t really discriminate between coronavirus types, so we expected that it would kill SARS-CoV-2 in just the same way.

Since SARS-CoV-2 is largely spread via droplets and aerosols that are coughed and sneezed into the air it’s important to have a tool that can safely inactivate the virus while it’s in the air, particularly while people are around.”

Since the coronaviruses, as well as influenza, are sensitive to far-UVC light then this could be a practical approach to put overhead far-UVC lamps in indoor public environments.

It can dramatically lower the risk of spreading viruses from person-to-person, especially through the winter.

Professor Brenner said:

“Because it’s safe to use in occupied spaces like hospitals, buses, planes, trains, train stations, schools, restaurants, offices, theaters, gyms, and anywhere that people gather indoors, far-UVC light could be used in combination with other measures, like wearing face masks and washing hands, to limit the transmission of SARS-CoV-2 and other viruses.”

The study was published in Scientific Reports (Brenner et al., 2020).

The Percentage Of COVID Patients With No Symptoms

The surprising proportion of infected people with the COVID-19 virus who show no symptoms.

The surprising proportion of infected people with the COVID-19 virus who show no symptoms.

A remarkable number of coronavirus patients have no symptoms of the disease at all.

Analysis of public datasets by the Scripps Research team suggest that nearly 45 percent of people carrying SARS-CoV-2 are asymptomatic.

An asymptomatic person does not show any symptoms of infection but is able to pass the virus to others for more than two weeks.

The very high percentage of asymptomatic cases most likely played a key part in the early stages of the coronavirus disease pandemic by spreading the virus silently and vigorously.

Hence, the research points out the necessity for extensive testing and contact tracing in order to reduce the spread of Covid-19 in populations.

Professor Eric Topol, the director of the Scripps Research Translational Institute, said:

“The silent spread of the virus makes it all the more challenging to control.

Our review really highlights the importance of testing.

It’s clear that with such a high asymptomatic rate, we need to cast a very wide net, otherwise the virus will continue to evade us.”

Professor Topol and his colleague gathered this data from 16 studies worldwide.

The data also includes cruise ship passengers, nursing home residents, prison inmates, among others.

Mr Daniel Oran, study’s first author, said:

“What virtually all of them had in common was that a very large proportion of infected individuals had no symptoms.

Among more than 3,000 prison inmates in four states who tested positive for the coronavirus, the figure was astronomical: 96 percent asymptomatic.”

When the team reviewed the collected information, they noticed that asymptomatic people can spread the virus for an extended time, possibly lasting beyond 14 days.

Viral load is the amount of virus present in an infected person and generally higher viral loads lead to worse outcomes.

The study found that the SARS-CoV-2 viral load in asymptomatic persons was at the same level as symptomatic patients, therefore the chance of viral transmission could be similar.

Also, just because they don’t carry any symptoms, it does not mean that there won’t be any harm.

For example, CT scans on asymptomatic patients of the Diamond Princess cruise ship show subclinical abnormalities in the lungs.

This is probably due to the impact of the SARS-CoV-2 infection on lung function despite not showing immediately.

The authors, however, admit that it is difficult to differentiate between pre-symptomatic and asymptomatic patients since long-term data and repeated testing are not available.

A pre-symptomatic individual is a person who has been infected with the virus and will sooner or later show symptoms, whereas an asymptomatic person will have silent symptoms of COVID-19 even though they are similarly infected.

Mr Oran said:

“Our estimate of 40 to 45 percent asymptomatic means that, if you’re unlucky enough to get infected, the probability is almost a flip of a coin on whether you’re going to have symptoms.”

The study was published in Annals of Internal Medicine (Oran & Topol , 2020).