Monthly Archives: February 2021

A severe newborn admitted to the National Children’s Hospital of Washington, D.C., was not only found to carry a new variant of coronavirus, but also the viral load was 51418 times that of other young patients. In addition, when sequencing the gene of the baby’s novel coronavirus, doctors found that the virus not only had a d614g mutation, but also found an unprecedented n679s mutation. Experts are confused and shocked – they worry that a new variant of the novel coronavirus will make infants and children “susceptible”. Experts said: it may be just a case.
Children are less likely to have severe cases of cowid-19
The Centers for Disease Control and Prevention (CDC) says everyone is likely to spread the disease, but young children are less likely to infect others. In this regard, the health Times reporter interviewed Li dongzeng, deputy chief physician of infection department of Beijing You’an Hospital, “at present, the problem of this newborn is still a case.” Because it is not sure where the mutant virus comes from in the body of the newborn, there are few people that the newborn can contact, and the source of infection is relatively easy to determine. Usually consider the possibility of mother transmission or nosocomial infection. If no infected person is found around, the problem of the newborn may eventually be a case.
The monitoring of the virus has been carried out all the time. The previous concerns were whether the infectious power of the mutated virus was stronger, whether the virulence was increased, and whether the protective effect of the vaccine was affected. This case suggests that we should pay attention to the increase of infectivity and pathogenicity of the mutated virus to children on the basis of the original observation. In the past, the pathogenicity of novel coronavirus to children was weaker than that of adults and the elderly. Most of the children infected were mild or asymptomatic. Li Dong once stressed that the problem of virus mutation needs continuous attention, and the current response is to continue to speed up the vaccination work, and try to achieve the immune barrier before the virus has a relatively large mutation, which is also the best protection for children.
Will the covid vaccine be available for people under the age of 18
At 8 a.m. on February 26, Hong Kong officially launched the covid vaccination program, with five priority groups including people over 60 years old. As the elderly over 60 years old are at high risk of severe cases, vaccination is also necessary. China’s adenovirus vector vaccine includes people over 60 years old in phase 3 clinical practice, so it is OK to be over 18 years old when it is approved for marketing. However, Li Dong once pointed out that whether the vaccine is open to children in the future depends on whether children are easy to be infected and whether there is a serious risk after infection, and the decision should be made after weighing the necessity.
If the virus mutates in the future, children are more susceptible or the risk of severe illness increases, we should consider liberalizing the age limit. However, vaccine trials can not be conducted with children ethically, and the data in this regard is more difficult to obtain. Only when the advantages outweigh the disadvantages, the emergency use will be approved.
How to avoid new coronal infection and mother to child transmission
New coronavirus is respiratory tract infection, novel coronavirus infection time of viremia is very short, that is to say, there is a virus in the blood for a short time, almost not through the blood transmission. The study has also been confirmed many times that the probability of nucleic acid detection from the blood of infected people is very high, so the probability of direct transmission from the uterus through the placental blood circulation to children is very low.
Li Dong once mentioned that if mother to child transmission, it is most likely after the birth of the child. If the mother is infected, or through the respiratory tract infection of the newborn is more likely, this just need to do a good job of maternal covid screening can be, if it is infected with the covid at the same time and is about to give birth, it needs to be delivered in a special negative pressure delivery room or operating room, when the new baby is born, timely isolation, and do a good job of monitoring.

China’s first covid vaccine for adenovirus vectors was approved for conditional marketing yesterday, the first in the world to enter the clinic after more than a year of research and development.
How safe is the vaccine?
How should the public choose?
In the second phase of Bai Yansong’s new media live program “Bai · Ask”, he spoke with Chen Wei, an academician of the Chinese Academy of Engineering, to analyze and answer questions about the process of developing vaccines.

01:38
When the vaccine is conditionally marketed, how effective is it?
In the program, Chen Wei said that the biggest effect of vaccines is to prevent severe diseases, and the current observation data show that the protection rate of vaccines against severe diseases has reached more than 90 percent.

Chen Wei: Vaccines are for the prevention and control of infectious diseases, and the covid vaccine is the most important technological means for the prevention and control of covid.
For us, the greatest effect of vaccines is to prevent severe illness, and the theory is no severe illness, no death.
So, if a vaccine can reduce the incidence of severe disease, it will reduce the death rate, and the vaccine is the most critical data, so the data on the protection rate of severe disease, this is the first thing to pay attention to.
Now we intensive protection can achieve full protection in Pakistan, which is critical in the placebo group vaccine a all have no, we did Pakistan (observed), more than eighteen thousand people around the world all people inside our intensive protection ratio can reach more than 90%, so for me this data is my first concern, especially welcome a data.

Up to now, more than 28.32 million new cases have been confirmed in the United States, and more than 504,000 people have died.
While infections have been on the decline in many parts of the country, several experts predict that the novel coronavirus variant could trigger another wave of outbreaks in the spring.

US President Joe Biden has sent a letter to Congress extending the state of emergency in the country due to the outbreak, the White House said on Thursday.
The Biden administration also announced that it will ship more than 25 million face masks to more than 1,300 community health centers and 60,000 food distribution points across the country to help people in vulnerable and poor communities.

A pedestrian wears a mask on a street in Manhattan, New York, the United States, Jan. 26, 2019.
China News Service reporter Liao Pan photo

The U.S. could be hit by another outbreak in the spring

A member of Vice President Harris’s press corps has been diagnosed

American media said that recently, many places in the United States pandemic infection showed a downward trend, more and more Americans are being vaccinated, but the threat of mutant novel coronavirus still can not be underestimated.
So far, there have been more than 1,900 cases nationwide of the novel coronavirus variant found in the United Kingdom, South Africa and Brazil, according to the CDC.

Experts are predicting that a highly contagious mutant novel coronavirus found in Britain could trigger another wave of infections in the United States within weeks.

Trevor Bedford, from the University of Washington and the Fred Hutchinson Cancer Research Center, said: “This could lead to a larger wave of outbreaks in April or May than we expected.”
Bedford also said he was skeptical that the outbreak would be contained by the summer.

A member of U.S. Vice President Harris’s press corps tested positive for a novel coronavirus Wednesday.
Members of the press corps have been told to return to their homes.

That same day, Alaska Gov. Mike Dunleavy tested positive for Novel Coronavirus, his office said.
He was in close contact with another newly infected patient a few days ago and has been in isolation ever since.

On February 16 local time, a mass vaccination station was set up at Oakland Arena in California, the United States, to open to eligible citizens.
The station will provide 6,000 doses of vaccine a day.
China News Service reporter Liu Guanguan photo

The United States is extending its state of emergency

Biden administration hands out face masks to vulnerable people

On February 24, the White House said that US President Joe Biden had sent a letter to Congress extending the state of emergency imposed in the country because of the new outbreak.
“As the new pandemic continues to pose a major threat to citizens’ health and national security,” the message said.
Therefore, the state of emergency declared on 13 March 2020 and effective on 1 March 2020 should continue beyond 1 March 2021.”

On the same day, the Biden administration also announced that it would ship more than 25 million face masks to more than 1,300 community health centers and 60,000 food distribution points across the country to help people in vulnerable and poor communities.

Between March and May, the government will distribute 25 million cloth masks in child and adult sizes that can be washed and reused, Jeff Zients, the White House’s response coordinator for the covid, announced at a news conference.
The masks will be manufactured in the United States, meet the CDC’s covid guidelines and will not affect the supply of masks to health care workers, it said.

In addition, the House of Representatives is expected to vote on the $1.9 trillion epidemic relief bill on the 26th.
The House Budget Committee approved the epidemic relief bill on Tuesday.

The bill aims to stimulate the U.S. economy and implement Biden’s proposal to provide more money for vaccines and other medical devices.
Opinion polls show that Americans want more economic support, but that Democrats and Republicans in Congress are sharply divided over how best to provide it.

In a recent interview with CCTV News, Zhong Nanshan said that China is seeing an increase in some local cases, which may be related to environmental and physical transmission.
Zhong pointed out that wearing masks, washing hands and keeping a distance are important ways to prevent environmental and physical transmission from person to person.
On the other hand, Zhong Nanshan also said that the monitoring of foreign articles should be strengthened.
In recent days, however, Zhong’s fears have come to pass as the mutated virus has spread rapidly around the world.

According to “Asahi Shimbun” reported, Japan’s National Institute of Infectious Diseases announced on February 18 that a new variant novel coronavirus has been found in Japan.
The new strain, named E484K by Japan’s National Institute of Infectious Diseases, is different from those found so far in Britain, as well as in South Africa and Brazil.
Japan’s National Institute of Infectious Diseases found that the new strain of the virus has obvious “immune avoidance” characteristics.
Even those who have been cured or vaccinated with the novel coronavirus are at risk of becoming infected by the new strain, which can cause a person’s immune function to be underused.

In addition to Japan, a new strain of the mutated virus has emerged in India, China’s neighbor to the west.
Indian health officials said as many as 240 new variants of the novel coronavirus strain have been found in various parts of the country, Russia Today reported Tuesday, calling for aggressive response.

Authority of India’s medical research and clinical institutions gu lei leah, director of the all India institute of medical sciences (Randeep Guleria), according to some of them will be coronavirus strain of new variants may be highly infectious, even more dangerous, some strains with immune escape mechanism “, some already have antibodies or vaccinated people likely infected again.

From the above report, we can see that the prevention of imported from abroad is still the focus of the current epidemic prevention work, for the emergence of the mutated virus in China, more attention needs to be paid.
Although the mutated virus has appeared in both east and west of China, the country’s vaccine has also recently brought good news.

Sinovac Biotech’s novel coronavirus vaccine is effective against a variant originally found in the United Kingdom and South Africa, the company’s Brazilian partner said Wednesday.
All signs have indicated that although novel coronavirus is changing, but the effectiveness of the Chinese vaccine is still very good.

The mayor of Dunkirk, a coastal town in northern France, had an urgent telephone conversation with French Prime Minister Jean-Pierre Castet and Health Minister Jean-Claude Verand about the new outbreak, confirming that they would study the upgrading of prevention and control measures in the region as soon as possible. Verand himself would also go to Dunkirk on 24 local time to consult with the town officials, the report said.

Media map of Dunkirk, France

In the past 7 days, 901 people per 100,000 population in Dunkirk were infected with the novel coronavirus, the highest infection rate in the country, local health authorities said Monday.
The novel coronavirus variant found in the UK is believed to be the main cause of the high infection rate in Dunkirk.
In response, local lawmakers called for compulsory wearing of masks in public places to prevent people from gathering, or “city closures” if necessary, on the basis of continuing to promote virus testing and vaccination.

More than 60 towns along the southeastern coast of France, which are also affected by the outbreak, decided to close them for the next two weekends, setting a precedent for local prevention and control in France.
In western France, where the disease has been relatively mild, local councillors have called for an easing of curfews.
French President Emmanuel Macron said it would be better to regionalize the prevention and control measures when he visited local agricultural projects.
French media also believe that this may become the main strategy of the French government to control the epidemic.

“There is a limit to how viruses can mutate, but we don’t know why,” said Vincent Lacanello, a professor of microbiology and immunology at Columbia University. “There are more possible genetic mutations than all the atoms in the universe. A large portion of the genome could be replaced.”
(credit: Shutterstock)

News of Beijing time of sina science and technology on February 23, according to foreign media reports, does the mutation degree of coronavirus have upper limit?
Experts point out that their variation seems to be endless…

Although the world’s scientific research experts are competing to develop novel coronavirus vaccine, but the coronavirus is still in mutation, also in genetic changes.
Include SARS inside, virus itself produces mutation also is normal phenomenon, but does the mutation degree of virus and human pathogenicity have certain limit?
Or will coronaviruses continue to evolve indefinitely?

“There is a limit to virus variation, but we don’t know why,” said Vincent Lacanello, a professor of microbiology and immunology at Columbia University. “There are more possible genetic mutations than all the atoms in the universe. A large portion of the genome could be replaced.”

Coronavirus gene sequence is made up of four different chemical groups on or molecules, length 29881 biochemical letters, these biochemical letters provide 9860 amino acids, these amino acids are an essential part of the viral proteins, when those chemical changes, amino acids also changed accordingly, which affects the shape of a viral proteins, which in turn shape changes will also affect the virus protein function, for example: how the virus together with human cells.

“Previous studies on other RNA viruses, such as the SARS virus that has a single stranded RNA as their genetic material, have found that more than half of the base pairs of these viruses can be altered,” says Lacanello.
Mathematically, this means that if a virus has 10,000 base pairs, there is a possibility of having 4^ 5,000 gene sequences.

Considering the visible universe in 4 ^ 135 atoms, the formula for similar to the SARS virus, then its genetic sequence may have 4 ^ 14941 kinds of combination way, this is just the calculation basis and biochemical changes, a chemical replaces another, Kane said: “there are other mutations in the genome, such as: loss or insert, which will further increase the gene sequence number of possibilities.”

But most of these mutations are irrelevant, and much of this will be eliminated immediately, Kane said: “some of the mutations are fatal, so we have never seen, but many mutations are neutral, they are accumulating, important mutations usually occurs on the spike protein of coronavirus, which it is used to capture human ACE2 cell surface receptors of weapons.
The spikes themselves are made up of 1,273 amino acids, and those amino acids are encoded by 3,831 chemical base pairs, so by the same mathematical logic, there are 4^ 1,916 variations in the coding of spikes, which is almost infinite, but nonetheless, there is a lot of redundancy in these mutations, encoding the same amino acids.”

In addition, not every mutation can be identified as a “mutation,” said John Moore, a professor of microbiology and immunology at Cornell University in the United States. “Some mutations occur quietly, and those that are identified and named often have distinctive characteristics, such as being more likely to be transmitted to humans, or being ineffective against vaccines.”

Powerful monitoring mechanism can help scientists through the random sampling of infected people, scans revealed the change of the virus gene, once they find a potentially important mutations, such as: where are these mutations in the genome, they can insert these mutations and ACE2 spike protein receptor interaction computer model, how to predict the mutation will show, but in the end in order to understand how this mutation change the behavior of the virus, they must do experiment for virus or protein.

Previous mutations

First SARS virus variants were found in the spring of 2020, when the original virus was first detected in wuhan was replaced by a new variant called D614G, according to Moore in the journal of the American medical association mentioned point of view, the new variety may appear in Europe, said Moore, until the end of the summer of 2020, scientists found that the virus mutations could enhance the ability to spread their copy.

While novel coronavirus doesn’t mutate as much as HIV or flu viruses, Moore noted that it can mutate when implanted in 100 million people.
In August 2020, another novel coronavirus variant called B.1.1.7 appeared in the UK, and its spread accelerated in November of the same year.
Early studies showed that the main mutation of novel coronavirus mutation, N501Y, again showed enhanced transmissibility, but antibodies applied to novel coronavirusD614G mutation and other previous coronavirus strains were effective against N501Y.

In addition, a more worrying will be coronavirus mutations appear in South Africa, it’s called b. 1.351 or N501Y. V2, within the virus variation and the British b. 1.1.7 is very similar, but it appears in the receptors and the spike protein in combination with regional mutations, the region is the position of the spike protein combined with human cells ACE2, will be coronavirus is the most key mutations E484K, it changed the shape of the receptor binding region (RBD), early enough to identify antibodies are difficult to identify the new variation of strain.

Several previous studies have shown that vaccines from companies like Moderna, Pfizer, Novavax and Johnson & Johnson can still protect against coronavirus mutations, but are not as effective as vaccines that target early viral mutations.

Another strain similar to B.1.351, called P.1, has also appeared in Brazil, worrying scientists because of its similarity to the South African novel coronavirus variant.
So far, scientists have found mutations in some strains of B.1.1.7, and even in E484K.

La Kane says receptor is a possible mutations area, it is composed of 223 amino acids, including 22 amino acids with human ACE2 receptors on cells in contact, any one of these amino acids is subject to change (because the receptor binding region potential gene sequence mutation), and increase its contact with human cells, so as to enhance their ability to invade.

Why do viruses mutate?

Mutations sometimes reflect a “builder effect,” in which the virus mutates and becomes dominant because the virus variant happens to enter a person who spreads the virus widely, but this does not necessarily mean that the mutation has an advantage.

“But sometimes the same or very similar mutations, such as the N501Y mutation, appear in different parts of the world, and that usually means that the mutation gives the virus some advantage,” said Mosan Said, assistant professor of biochemistry at Boston University School of Medicine and a researcher in the National Laboratory of Emerging Infectious Diseases.

‘The coronavirus is already very susceptible to infecting humans, so any advantage it might get from a mutation in the future might not be that big,’ Dr. Said said. ‘That’s the equivalent of having your radio on at 10 decibels. Turning it up to 11 decibels doesn’t make a big difference.’

What will happen when mass vaccination against coronavirus begins soon?
“In this case, the vaccine might stimulate the ‘escape mutation’ of the virus, which would achieve the ability to block the neutralizing antibodies,” said Said.

Future virus mutations

SARS virus in the human transmission time is very short, currently scientists can not based on the simulation or the history of the virus to predict the future of the virus will be what kind of mutation, there is a lot of randomness.

Moore said: “we don’t call the shots, we only respond to the virus, in other words, the virus mutation happened in the wild, scientists are studying infectious and lethal, they and their impact on the vaccine’s escape mutation, though a step ahead before the virus mutates is useful, for example: based on the simulation test, predict whether other mutations may occur, but considering the extent of the virus, it may be impossible.
The interactions between proteins and receptors or antibodies are very flexible, and they can tolerate viral mutations in many different ways, and they end up at the same endpoint, so you can’t predict what’s going to happen next.”

Kane noted, scientists can predict some very obvious virus mutation, change some amino acids such as spike protein affects the antibodies, or spike receptor area changes affect the virus enters human body cell adhesion and invasion ability, although scientists cannot predict which mutations can bring advantages to the virus, but they know, the more the spread of the virus, can appear more mutations.

Strong selection pressure, such as the use of a very effective vaccine, may reduce the chance of the virus replicating and mutating, while very weak selection pressure means that the virus does not have to choose to mutate, so any change provides only a negligible advantage.

The trouble comes when we apply moderate levels of selection pressure to the virus, for example: when you don’t have a strong antibody response, widespread use of a vaccine that has little effect, or extending the time between the first and second doses, can be a “breeding ground for new strains of the virus.”
“We are now aware of that,” Moore said.

So in order to prevent future mutations, we need to make sure that we vaccinate people on time to prevent what are called “escape mutations,” we need to prevent the virus from spreading, which increases the probability that the coronavirus will mutate further.

Moore points out, because we can’t predict what specific mutations occur ahead of time, to be two steps behind the virus mutation, rather than twenty steps, the only way is to greatly strengthen the monitoring of new variants of the virus, so scientists can before the spread of the virus, found in the laboratory and test the impact of the new virus mutation.

, according to media reports, Finnish foreign revealed a message that the “vita” laboratory located in Helsinki last week found that there is a new variation will be coronavirus, Finland will variant will be coronavirus known as Fin – 796 – h, the mutant viruses have some British and characteristics of the external reports of strains in South Africa, but it is different from these countries reported to who the variation of the virus, because through the study found that the sequence of the virus is unique, and Finland, according to the current will be coronavirus detection methods, not be able to detect the mutation of the virus,
As soon as the news broke, it caught the world’s attention, and it was clear that everyone’s worst fears had been realized.

Although authorities in Finland immediately stressed that they should not worry too much about the new mutant virus, many people were in a panic.
Mutated virus there for all to see the impact of the outside world, have to mention is the mutated virus reported to who, the discovery of a kind of transmission speed, infectious or fatality rate is higher than the ordinary will be coronavirus mutated virus, the virus, the epidemic worse at the speed of visible to the naked eye, and open the floodgates, still hasn’t seen better, in addition the mutation after the virus appears, also has made great influence in other countries, now many countries have claimed to have found that the virus, the United States is the worst, the mutant virus spread to more than 40 states.

Beyond the UK, there are a lot of countries have declared found mutation, even lead to some strains in the new vaccine failure, under this big background that almost everyone is heard mutation, after all, to deal with will be coronavirus has been very difficult, now also appears more difficult to deal with the variation of the virus, this means that countries all over the world to get rid of the difficulty of the outbreak of the new champions league became larger.

In front of the report of these mutated viruses still can be found, and now the Finnish side found novel coronavirus, may even nucleic acid can not be detected, once in a large range of proliferation, the consequences are unthinkable.

Experts at the Finnish laboratory where the virus was discovered have said only when it was discovered. No conclusions have been reached as to how the patient became infected or how transmissible or resistant the virus is. Experts do not know whether the virus has spread outside Finland.

Most eyes are now on Finland, where studies of the new mutated virus have begun to find out more about whether the virus’s ability to spread could make the new vaccine ineffective.

In fact immediately after the discovery of the new strains in Finland, told the news for the world is a good thing, because Britain found earlier after mutation, because there is no alarm, the first time make Britain itself is not only a heavy price, more in other countries should all be missed the best opportunity, British mutated virus spread around the world.

The timely sound of the Finnish alarm is undoubtedly a wake-up call to all countries, so that countries around the world can respond quickly, take measures to deal with, which can greatly reduce the emergence of a new mutation of the virus to the global losses.

All over the world constantly spread novel coronavirus variant virus strains, now scientists more found that 2 strains of different variants of novel coronavirus strains can also be further combined, recombination into a mixed virus!

Researchers at the Los Salamos National Laboratory in New Mexico discovered for the first time in a single sample the combination of the British strain B.1.1.7 and the California strain B.1.429.
She presented the research at a meeting of the New York Academy of Sciences in early February, noting that unlike common variants, which mutate one at a time, syncytiviruses can mutate multiple times at a time.

It is still unclear what impact this hybrid strain will have on the outbreak.
B.1.1.7 and B.1.429 are known to be easily transmissible and resistant, respectively. Cobb believes that the hybrid strains may have both characteristics, and fears that this could make the outbreak more severe.

The study also pointed out that the presence of the mutant combination means that some patients may have been infected with two different strains of the virus.

But David Pound, a biology researcher at Temple University in Pennsylvania who studies virus variants, says that novel coronavirus hybrids are common, and that there is no evidence of a large number of synthetized viruses.

At present, the syncyte virus has not been named.
It is understood that the syncytiovirus is produced when two strains of the virus infect the same cell and exchange genes when replicating. This kind of situation generally occurs under specific circumstances or coincidences, and the probability of occurrence is rare.

In most cases, the mutated hybrids produce a mutilated virus that can no longer be transmitted, but there are exceptions, said Dr. Furness, a professor of epidemiology at the University of Toronto.
How well the vaccine will work against the new hybrid is unclear, but he said: “It is a routine practice to adjust the vaccine, just as we have a different flu vaccine every year.”

‘We should be aware of the dangers of air travel if we know that densely populated environments tend to produce this strain,’ Furness said.

Sly, a professor emeritus at Wyson University’s School of Occupational and Public Health, notes that this may be the first reorganization, and it may not be the last.
“The more viruses there are in the world, the more mutations there are in the mix, and the more likely it is that you will produce a brew that is extremely dangerous,” he said.

The mutation found in this study is a Genetic recombination of the following types of virus mutations.

Virus Variation Popular Science (from Baidu Baike)

Viruses are prone to mutating.
Its genetic code or genome is mainly concentrated in the nucleic acid chain, as long as this nucleic acid chain changes will affect the characteristics of their offspring.
In fact, viral genomes are not static as they proliferate, but mutate automatically from moment to moment.

mutation

A virus Mutation is a chemical change in the sequence of nucleic acid bases in the genome, which can be a single nucleotide change, or the deletion or translocation of hundreds or thousands of nucleotides.
A variety of physical and chemical Mutagens can improve the mutation rate, such as temperature, radiation, 5-bromouracil, nitrite and other effects can induce mutation.
The mutant is different from the original wild-type virus, showing changes in virulence, antigen composition, temperature and host range.

Virulence changes have strong and weak strains, the latter can be made into weak live virus vaccine, such as spinal fluid polio vaccine, measles vaccine, etc.

Conditional lethal mutant refers to a virus that can grow under certain conditions after mutation, but can not reproduce under the original conditions and is killed.
Among them, the most important was temperature-sensitive conditional lethalmutant (TS strain), which could proliferate when incubated at a specific Temperature (28-35 ℃), but could not proliferate when incubated at a non-specific Temperature (37-40 ℃), while the wild type could proliferate at both temperatures.
This is apparently because the protein encoded by the mutant gene lacks its proper function at unspecified temperatures.
Therefore, most TS strains are also attenuated strains.
The TS strain has been isolated from many animal viruses, and the strains with good genetic stability have been selected for the preparation of live alkali vaccines, such as influenza virus and the TS strain of spondylitis virus.

The host adaptive burst strain, such as the mutant strain of rabies virus, ADAPTS to proliferate in the rabbit brain and changes from “street virus” to “fixed virus”, which can be used as rabies vaccine.

Genetic recombination

When two related viruses infect the same host cell, their Genetic material is exchanged, resulting in heritable progeny that are different from their parents. This is called Genetic recombination.

Recombinations between live viruses, such as those between two subtypes of influenza virus, may result in genetic recombination to produce a new hybrid strain with one parent of hemagglutinin and the other parent of neuraminidase.
This is of great significance in exploring the principle of natural virus mutation.
Influenza causes a pandemic every decade or so, probably due to genetic recombination between human influenza viruses and influenza viruses in certain animals (chicken, horse, pig).

For example, when two strains of the same virus are inactivated by ultraviolet light, if they are cultured together, the inactivated virus can often be revived to produce infectious virions. This is called Multiplicity reactivation. This is because the damaged gene sites on the nucleic acids of the two viruses are different, and the reactivation is due to the mutual complement of the two viruses.
So now it is not necessary to inactivate the virus with ultraviolet light to make a vaccine, in case the virus comes back to life.

For example, a vaccine strain of influenza A virus (A0 or A1 subtype) that can grow well in chicken embryos is inactivated by ultraviolet light and then cultured together with live Asian influenza A virus (A2 subtype) to produce influenza A2 subtype virus with the former characteristics, which can be used for vaccine production. This is called Cross reactivation.

Scientists are studying novel coronavirus in greater depth as people around the world begin mass vaccination with the covid vaccine.
The world’s first Novel Coronavirus Human Challenge Trial is now set to launch in the UK.

February 17, according to CNN reports, local time, the British government web site said in a statement, the country approved a will be coronavirus “human” challenge test plan, not more than 90 healthy adult volunteers will be exposed to will be coronavirus environment, aims to provide scientists study the body’s immune system to will be the reaction of coronavirus, analyzing the factors that may influence the spread of the virus.

However, even in a controlled setting, the study of infecting healthy volunteers with the potentially deadly novel coronavirus is controversial.

Meanwhile, the situation in the UK remains dire.
A new variant of novel coronavirus, known as B.1.525, has been found in the UK, with 38 people infected so far, according to Public Health England.

The world’s first covid human challenge trial has been approved in the UK

Coronavirus is the first country in the world to receive approval for a novel coronavirus challenge in humans, with the UK government planning to launch the study within a month, according to the UK’s Clinical Trials Ethics Authority.

The world’s first novel Coronavirus “human challenge trial” has been approved in the UK.
/ Screenshot from a British government website

In the initial phase of the study, the scientists will analyze the minimum amount of virus needed to infect humans with novel coronavirus.
The plan is to recruit up to 90 healthy adult volunteers, aged between 18 and 30.

Before the volunteers are allowed to take part in the trial, they will be placed in isolation at London’s Royal Free Hospital and exposed to Novel Coronavirus in a safe, controlled environment.

Due to limited knowledge about the recently discovered mutant novel coronavirus, to ensure the safety of the volunteers, the study will use the novel coronavirus strain that was circulated in the UK in March 2020.

Two days after entering the isolation facility, researchers will drop Novel Coronavirus into the noses of volunteers, according to The Guardian.
The volunteers were given daily blood tests and nasal swabs for at least the next 14 days, while researchers monitored them around the clock.

Up to 90 volunteers in the UK will take part in a pioneering trial of the novel coronavirus.
/ Screenshots from the Guardian

NHS hospitals and the North Central London intensive care network will work closely to ensure the volunteers are given 24-hour care and that the research does not affect the ability of UK healthcare staff to care for other confirmed patients.

After completing the tests, all volunteers were tested twice for the virus, and only those who were both negative were allowed to leave the isolation facility.
The volunteers will then be followed up for another 12 months to see if they have long-term symptoms.

Volunteers who took part in the human challenge were not paid, but would receive compensation of around £4,500, The Guardian said.

So far, the British government has funded the research with an estimated 33.6 million pounds.
The research will be carried out by the government’s Vaccine Task Force, Imperial College London, the Royal Free NHS Trust in London and leading clinical company Hvivo.

The study could give scientists insight into how the body’s immune system responds to novel coronavirus, CNN reported.
At the same time, once a preliminary study has been conducted, scientists will also be able to test the effectiveness of the candidate vaccine candidate by vaccinating some volunteers during the trial, which has proved to be safe, and thus move the development process forward.

Up to 90 healthy volunteers will be exposed to Novel Coronavirus in the first global trial.
/ Screenshot from CNN

Human challenge testing remains controversial

According to the British government’s website, similar human challenges have been carried out safely for decades and have played an important role in the treatment of diseases such as malaria, cholera, norovirus and flu.

In a statement released in May 2020, the World Health Organization said that human challenge testing is ethical when certain criteria are met, but, more importantly, trials should be conducted within an ethical framework in which volunteers are fully informed and their decisions are taken in a deliberate and careful manner.

According to the Washington Post, some public health experts believe that human challenge testing has played a key role in developing a vaccine and treating patients with a confirmed diagnosis.

“While the vaccine developed so far is effective against the majority of circulating variants of Novel coronavirus, the human challenge test could give us the ability to rapidly test other vaccine candidates,” said Robert Reid, a professor of infectious diseases at the University of Southampton in the UK.

Clive Dix, head of the UK’s Vaccine Task Force, said: “There are already safe and effective vaccines available in the UK, but it is vital that we continue to develop new vaccines and treatments for novel coronavirus.”

“We hope that the Human Challenge Trial will provide unique insights into how Novel coronavirus is transmitted and help us understand which vaccine candidates best prevent infection,” Dix added.

The world’s first “human challenge trial” for novel coronavirus, which infects healthy volunteers, has been approved in the UK.
/ Screenshots from The Washington Post

However, such tests are controversial because healthy volunteers are deliberately exposed to the virus.
With more than 15 million people in the UK having had their first dose of the vaccine so far, some have questioned the need to challenge human trials.

Terence Stephenson, chairman of the UK’s Health Research Agency, said: “Families and friends are not able to see volunteers during isolation, which puts a lot of pressure on young people aged 18 to 30.”

Jacob Hopkins, 23, who is about to become a volunteer, told The Washington Post, “I don’t know the real risk, but I’ve been heavily screened, and for someone who is young and healthy, the risk of this study seems very small.”

Hopkins stresses that his biggest concern is the potential long-term effects, “but that’s not enough to make me change my mind.”

England reappears with the novel coronavirus

According to research published by Imperial College London, the rate of infection in England has fallen by two-thirds since the massive blockade was introduced in January 2020, with the rate in London falling by around 80%.

However, children aged 5 to 12 years and young people aged 18 to 24 years remain at high levels of illness.
Meanwhile, between February 4 and February 13, one in 200 people tested positive for the virus, meaning it continues to spread.

According to the report released by the British government on February 17, 12,718 new cases were confirmed in the UK in the past 24 hours, bringing the total number of confirmed cases to more than 4.08 million.
There were 738 new deaths, bringing the total number of deaths to more than 119,000.

UK outbreak data.
/ Screenshot from a British government website

More worrying is the discovery in Britain of a new variant called novel coronavirus.

A mutant novel coronavirus known as B.1.525 has been found, Public Health England said in a statement on Tuesday.
So far, 38 people have been infected, including 36 in England and two in Wales, with samples of the mutant novel coronavirus dating back to December 2020.

“B.1.525” has now been classified by Public Health England as an “under investigation” variant of novel coronavirus and is being studied by public health experts to understand the possible risks posed by this variant.

A new variant of the novel coronavirus has been discovered in Britain.
/ Screenshot from the BBC report

According to Public Health England, the B.1.525 mutant novel coronavirus, known as E484K, has been found in Denmark, Nigeria and the United States.
The mutation has also been observed in a variant novel coronavirus found in Brazil and South Africa, and is thought to help it evade the body’s immune system defenses.

Andrew Hayward, an epidemiologist at University College London, said: “Fortunately, this mutant novel coronavirus does not appear to be spreading as fast as other strains and remains at very low levels of transmission, but we need to keep a close eye on it to prevent what could happen.”

According to the latest news, researchers in the New Mexico laboratory in the United States, the first time in a virus sample found a variant of the virus strain “B.1.1.7” found in the United Kingdom and the United States found a variant of the strain “B.1.429” found in California.
Scientists fear that this combination will evolve into a new strain that is more infectious and resistant to drugs.