How fierce is the recently popular ＂Delta＂ mutant strain？
This week, a mutant strain of COVID-19 called "Delta" sounded a new alert for the global epidemic.
According to the Guardian, 99% of the new cases in Britain are infected with the "Delta" strain. WHO pointed out that 92 countries and regions around the world have detected the spread of the "Delta" strain. On June 25th, WHO Director-General Tan Desai was worried.
WHO Director-General Tedros Adhanom Ghebreyesus:"Delta" mutant strain is the most transmissible strain found so far, which has appeared in at least 85 countries and regions and is spreading rapidly among unvaccinated people.
A few days ago, WHO confirmed that the strain had spread to 92 countries and regions.
Swaminatan, chief scientist of WHO:Because the spreading ability of the "Delta" mutant strain has been significantly enhanced, this mutant strain in Covid-19 is becoming the main Covid-19 mutant strain in the world.
The "Delta" mutant strain was first discovered in India in October, 2020, and was named B.1.617.2 scientifically.
In May this year, in order to avoid the stigma associated with a specific country and facilitate its use, WHO announced the use of Greek letters to name the mutant strains found in various countries.
The four mutant strains listed as "needing attention" by WHO have new names corresponding to the first four letters of the Greek alphabet: alpha, beta, gamma and delta.
Among them, alpha, beta and gamma mutant strains all have a mutation called "N501Y", which seems to strengthen the infectivity of the virus to cells and make the virus spread more easily.
Beta and gamma mutant strains also have a key mutation, called "E484K", which may enable the virus to avoid being blocked by the immune system.
The mutation of "Delta" mutant strain is different. Initially, "Delta" was considered as a "double mutant" virus.
Maria Van Kokhov, Technical Director of WHO Health Emergency Project:First discovered and reported by India, there are two mutations, E484Q and L452R.
Djamil, dean of Trivedi School of Biological Sciences, Asoka University, pointed out in an exclusive interview with Xilong Times that the statement of "double mutation" is not accurate. The Delta variety contains 15 mutations in total, 6 of which occur in spike protein, and 3 of them are key: L452R, E484Q and P681R.
L452R improves the ability of virus to invade cells, E484Q helps to enhance the immune escape of virus, and P681R can also make virus enter cells more effectively.
The combined effect of these mutations makes the "Delta" mutant strain partially avoid some neutralizing antibodies, so it is more infectious.
Maria Van Kokhov, Technical Director of WHO Health Emergency Project:We know that the "Delta" variant does increase the spread, which means that it can be more easily spread among people. This is related to known mutations, which allow viruses to adhere to cells and invade cells more easily.
The BBC synthesized data from Imperial College London and The Lancet magazine, and compared the basic infection number of COVID-19 mutant strain with other viruses, that is, R0.
R0 of "Alpha" mutant strain is 4-mdash; 5. That is to say, without any intervention of epidemic prevention measures, a patient infected with "Alpha" mutant strain can continue to transmit the virus to 4— Five people.
R0 of Delta mutant strain is 5-mdash; 8；
The R0 of mumps is 12;
The R0 of measles is 18.
A study in The Lancet, an international medical journal, shows that the risk of hospitalization is twice as high for people infected with the "Delta" mutant strain as for people infected with the "Alpha" mutant strain.
Hairdressing shop owner Shawang:We used to earn 300,000 to 350,000 rupees a month, but now we are completely losing money, and most hairdressers have returned to their villages.
This is Maharashtra, one of India’s major economic and cultural centers.
According to the international authoritative journal Nature, in the past few months, the highly contagious "Delta" mutant strain has spread rapidly in India and has become the main strain prevalent in Maharashtra. But the ferocity of "Delta" does not stop there.
In March this year, researchers first discovered a further variant of the "Delta+"strain in Europe. In early April, "Delta+"was also detected in Maharashtra.
According to a report by India’s New Delhi TV Station on June 23rd, at least 40 cases of "Delta+"infection have been found in seven Indian states including Maharashtra, Kerala and Madhya Pradesh, among which Maharashtra has reported more than 20 cases.
Trust card for director of hospital intensive care unit:A large number of vulnerable people live in rural areas, suburbs and small towns. This time we expect the virus to spread to these areas intelligently.
At present, two-thirds of the new cases in COVID-19 come from rural areas, and about 30% of the urban population has been vaccinated with at least one dose of COVID-19 vaccine, compared with only 15% in rural areas.
Local health workers also said: "When we go for virus testing or talk to them, sometimes people will tell us to leave, otherwise they will beat us, and sometimes they will throw stones and bricks."
This week, the Ministry of Health of India pointed out that the "Delta+"strain has stronger transmission ability, and adjusted the classification of this new strain from "variant of interest" to "variant of concern".
Maharashtra Health Minister Top:We have issued instructions to all subordinate officials to pay close attention to infection cases related to "Delta+"variant.
According to a report by the BBC on the 24th, the "Delta+"strain has been found in at least 10 countries including the United States, Britain, Portugal, Switzerland, Japan and Russia. Lisbon, the capital of Portugal, has recently entered a full blockade every weekend.
Portuguese National Guard spokesperson Cagnotto:Drivers know the rules, they know that it is forbidden to leave and enter Lisbon metropolitan area, and the traffic on Friday afternoon is much less than usual.
Newsstand operator:I think all measures to reduce the number of cases are good. I am located in the city center and I see that all foreign tourists don’t wear masks.
Lisbon and the Tejo Valley are the regions with the most serious epidemic in Portugal.
According to the report released by the Portuguese National Institute of Health, among the recent new cases in Lisbon, the infection cases related to the "Delta" mutant strain accounted for more than 60%, and some local epidemiologists believe that this proportion has reached 70%.
Due to the obvious deterioration of the epidemic, the United Kingdom removed Portugal from the British green navigation list in early June.
Simon, an English tourist in Portugal:I’m very angry. I’ve missed half my holiday. Now it costs me a lot of money to change my flight in order not to be quarantined after returning home.
On June 21st, Portuguese Health Minister temido said that the spread speed of the "Delta" mutant strain has exceeded the speed of vaccination.
Portuguese cabinet spokesman da Silva:We think it’s very important now not to let Lisbon’s current difficulties spread to other regions.
On June 23rd, the gymnasium of Lisbon University was temporarily used as the vaccination center for COVID-19, which was operated by the Portuguese Armed Forces to vaccinate people over 50 years old. President De appeared at the vaccination site.
Portuguese President De:We are here to call attention to this priority, and the Portuguese are racing against time with unity and cooperation.
On June 24th, during the EU summit, German Chancellor Angela Merkel said that Germany and Europe were treading on thin ice.
German Chancellor Angela Merkel:We need to be vigilant, especially in the face of Covid-19’s new variety "Delta", which reminds us to be cautious.
A few days ago, Merkel had just received the second dose of COVID-19 vaccine.
Willer, Director of robert koch Research Institute:Since the second week of June, because there is always a certain time lag in statistics, the proportion has reached 15%, but we think the proportion will certainly be higher today.
German Federal Minister of Health Span warned that it was only a matter of time before the Delta strain continued to spread and became the most important strain in Germany.
On June 23rd, the European Center for Disease Control and Prevention released the latest epidemic model forecast: It is estimated that by the beginning of August, 70% of the newly confirmed cases in the EU and EEA countries will be caused by the "Delta" mutant strain, and by the end of August, this proportion will rise to 90%.
Kruger, Director of the WHO Regional Office for Europe:The worrying "Delta" variety, showing stronger transmission and some immune escape ability, is preparing to take root in the European region.
In contrast, on June 24th, US President Biden appeared in Raleigh, the "Oak City" in North Carolina. According to Bloomberg, this is a vaccine trip.
US President Biden:The dangerous mutant strain continues to spread, and it is now a very common variant in the United States. People who are not vaccinated are very vulnerable, which is also a concern of experts about the "Delta" strain.
In May this year, Biden confidently announced the next stage of epidemic prevention goal in the United States, that is, 70% of American adults should be vaccinated with at least one dose of COVID-19 vaccine before July 4, the day of American independence, and 160 million American adults should be vaccinated with two doses.
However, according to the CDC data, as of June 22nd, only about 65% of adults in the United States have received at least one dose of COVID-19 vaccine. Only 55% in North Carolina. White House officials admit that Biden’s epidemic prevention goal may not be completed as scheduled.
White House COVID-19 Epidemic Response Coordinator Zienz:There is still a lot of work to be done in this country, especially for people aged 18 to 26. The fact is that many young people in the United States feel that the COVID-19 epidemic will not affect them, and they have no desire to get vaccinated.
On June 24th, a strange conversation between Biden and CNN reporter further aroused people’s anxiety.
In the eyes of some Americans, Biden was once again questioned as to whether he could be trusted, except for the new nickname "Joe the Terrible".
Defense lawyer Woodfield:For the first time in the history of our country, private employers told their employees that as a condition of your employment, you must take part in the vaccine test, which has never happened in the history of our country.
In Houston Methodist Hospital, Texas, hundreds of employees were fired or forced to resign because they didn’t want to be vaccinated. Nurse bridges took the lead in bringing a lawsuit against the hospital.
Bridges, a former nurse at Houston Methodist Hospital:At first, 117 people joined us, and now we will add another 70 people. We hope that Methodist hospitals will be responsible for their actions, and we hope that the public will know that we should not lose our jobs.
Bloomberg pointed out that the COVID-19 epidemic is spreading rapidly in several states with insufficient vaccination, especially in Missouri and Utah, where more and more young people go to hospitals. These data release a clear signal that the epidemic in the United States has rebounded.
Frederick, Chief Executive Officer of Missouri Mercy Hospital:At the end of this week, 60% to 65% of the patients who entered the intensive care unit were under 40 years old, which was shocking compared with last year.
According to the data released by the US Centers for Disease Control and Prevention on June 22nd, more than 20% of the newly confirmed cases in the United States in the last two weeks were infected with the "Delta" strain, while in the report released on June 8th, this figure was only about 6%.
Fauci, director of the National Institute of Allergy and Infectious Diseases:Now this proportion is 20%, and it can be predicted that it will become the main virus-causing strain in the next few weeks to a month.
At present, the high-profile European Championship is in full swing in 11 European countries, and in the face of the fierce counterattack epidemic, UEFA is also very headache about what to do in the next competition.
Not only that, there is only less than one month before the opening of the Tokyo Olympics. This week, Japanese public health experts also said that "the Tokyo epidemic tends to rebound, which is very worrying."
On June 25th, Beijing time, UEFA announced the best team in the group stage of the European Championship, among which Cristiano Ronaldo, the Portuguese star who was crowned the top scorer in the history of the European Championship finals, was selected with the highest score.
Wembley Stadium in London, England will be the venue for the semi-finals and finals of the European Championship. On June 22nd, UEFA announced that the British government has agreed to further increase the attendance rate of Wembley Stadium during the European Championship, and the opening rate of the stadium will increase from 25% during the group stage to 75%, which means that more than 60,000 spectators will be accepted in each of the three semi-finals on July 6th and 7th and the final on July 11th.
Wembley Stadium will witness the largest audience of British sports events in 15 months, the British Department of Digitalization, Culture, Media and Sports wrote on the top official Twitter.
British Health Minister Hancock:The European Championship is going well. The final will be held at Wembley Stadium. I also went to Wembley on Friday night. It was great to hear the noise of the crowd again.
However, the recent obvious deterioration of the epidemic in Britain has also caused many people to worry about whether holding large-scale events here will bring risks.
Italian Prime Minister Mario Draghi:Yes, I advocate that the finals should not be held in countries where the risk of infection is growing rapidly.
German Chancellor Angela Merkel:Britain is a high-risk area for virus variants, which means that anyone from Britain to Germany will need to be quarantined for 14 days.
Since May, the number of newly confirmed cases in Britain has increased rapidly, and has recently rebounded to more than 10,000 cases per day.
On June 25th, the British Ministry of Public Health said that among the newly confirmed cases in the past week, 96% were caused by the "Delta" strain, compared with 99% in the previous week, and the cumulative number of people suffering from the "Delta" strain in Britain has reached 11157.
British Prime Minister Johnson:This is why we are so worried about the "Delta" variant, which is now spreading faster than the third wave of epidemic predicted in February.
On June 18th, the match between England and Scotland was held at Wembley Stadium, and a large number of Scottish fans "went south" into London, which brought a lot of pressure to the prevention and control of the epidemic in London.
On June 13th, Sadiq Khan, the mayor of London, was photographed celebrating the 1-0 victory of the Three Lions in Trafalgar Square. The excited crowd seemed to have completely forgotten to observe the epidemic prevention regulations.
According to the British "Times" report, among the 24 teams participating in the European Championship, except England, Scotland and Wales, the countries and regions to which the other teams belong are all on the orange or even red list of the epidemic in the UK. According to the British epidemic prevention policy, they must be quarantined for 10 days after arriving in the UK. Previously, the British government granted "isolation exemption" to the players, coaches and staff of the participating teams in order to hold the event smoothly. However, UEFA requested that 2,500 officials and VIPs also be granted "isolation exemption" so that they can directly enter Wembley Stadium to watch the game.
This puts the British government in a dilemma. If it accepts UEFA’s request, it will arouse the dissatisfaction of its own people. If it refuses, UEFA threatens to move both semi-finals and finals to Budapest, Hungary, where the epidemic situation is well controlled, which is also unacceptable to Britain.
The same dilemma also happened in Japan. On June 20th, the Olympic Village of the Tokyo Olympic Games was opened to the media for the first time, and the place where more than 10,000 athletes from more than 200 countries and regions lived was finally presented to the world.
Seiko Hashimoto, Chairman of the Tokyo Olympic Organizing Committee:With regard to the response to the COVID-19 epidemic, up to now, 80% of all people from all over the world have been vaccinated.
However, just the day before, on the 19th, one of the nine members of the Ugandan delegation who arrived in Tokyo tested positive for COVID-19 screening at the airport. Japanese Olympic Secretary Tamayo Marukawa confirmed that this person was infected with the "Delta" mutant strain. However, all members of the Ugandan delegation had completed two doses of vaccination before going to Japan and provided negative test certificates within 72 hours. On the 23rd, another member of the Ugandan delegation was tested positive, and many Japanese workers who came into contact with it were also isolated, which cast a shadow over the upcoming Olympic Games.
On July 23rd, the Tokyo Olympic Games is about to open, less than a month from now. According to the Nihon Keizai Shimbun, about 94,000 people will enter Japan during the Olympic Games, which has sparked a debate about the number of spectators at the Olympic Games.
On June 21st, the Japanese government, the Tokyo Olympic Organizing Committee, the Tokyo Metropolitan Government, the International Olympic Committee and the International Paralympic Committee held five-party talks online, and it was formally decided that the number of people watching the Olympic Games on site should not exceed 50% of the venue capacity, with a maximum of 10,000 people.
Seiko Hashimoto, Chairman of the Tokyo Olympic Organizing Committee:We have received a suggestion that if no spectators are allowed to enter, we can hold the Olympic Games more safely.
Many experts, including Shigeru Omi, the chief medical consultant of the Japanese government, believe that it is the least risky way to hold an event without an audience.
Only in this way, the publicity effect of the Tokyo Olympic Games will be weakened. For the upcoming election of the Japanese House of Representatives after the Olympic Games, the boosting effect will also be discounted. Kyodo News noted that Prime Minister Suga Yoshihide was anxious about this situation.
Japanese Prime Minister Suga Yoshihide:If it is necessary to implement a state of emergency, I will respond flexibly, not open the stadium to any audience, and hold an event with public safety as the first priority.
According to the research forecast of Xipu Bo, a professor of epidemiology at Kyoto University, by July 23rd, the opening of the Tokyo Olympic Games, the positive cases caused by the "Delta" mutant strain will account for 70% of all newly confirmed cases.
According to the results of a poll released by Kyodo News, among 2,000 respondents, 86% are worried that the Olympic Games and Paralympics will lead to the further expansion of the epidemic, 40.3% think that the Olympic Games should be held in an empty venue, and 30.8% think that it should be cancelled.
Tokyo citizens:As a resident, I am worried that the city may become crowded and Covid-19 will spread further.
Regarding the situation of epidemic prevention and control, Indian immunologist Barr stressed that no matter what kind of Covid-19 is targeted at, "vaccination will always put you in a better position to fight infection".