Despite high-intensity distancing, the number of corona patients is hardly decreasing.
The increase in the number of confirmed cases is driven by the surge in delta mutations.
The introduction of delta mutations into Korea was first confirmed on April 18.
For about two months, the delta mutation rate among domestic confirmed cases did not exceed 2.5%, but the situation has changed dramatically since mid-June.
These days, 3 out of 10 confirmed cases, and 7 out of 10 among mutated infected people, are said to be delta mutations.
Coincidentally, the surge in the number of Delta-mutant confirmed cases has been evident since June 20, when the government announced a policy to ease distancing.
The remarks of government officials also show a significant temperature difference between late June and mid-July.
As of the end of June, the detection rate of delta mutations was stable, "not at a level of concern," and this week, it is "very serious."
Patients infected with the delta mutation have been shown to be at an increased risk of exacerbation of gastritis.
According to Bang Daebon (Central Quarantine Countermeasures Headquarters), 32 (4.1%) of 790 people classified as delta mutations until the 10th were critically ill.
Among all confirmed cases, the proportion of patients with severe cases (1.3%) was higher than that of those infected with 'alpha mutation' from the UK (2.2%).
Delta mutations were first identified in India in October 2020.
The fact that the propagation power of delta mutations reached 2.7 times was already known to the world through the disaster that took place in India.
This is why it is pointed out that Korea should not prepare guidelines for easing distancing at the time before the holiday season, but should have prepared more thoroughly, such as thorough management of inbound travelers from countries where delta mutations are prevalent.
Delta mutation is not the only problem.
In South America, lambda mutations are rampant.
According to the WHO, in the two months since April, 80% of new coronavirus cases in Peru were infected with the lambda mutation, and it is rapidly spreading to neighboring countries.
Argentina's President Fernandez was also infected with the lambda mutation.
The lambda mutation is currently spreading to 29 countries, including the United States and the United Kingdom.
Just like the alpha (from the UK), beta (from South Africa), and delta (from India) mutations, there is no law that says that lambda mutations should not enter Korea and cause problems.
Variants are named in the Greek alphabet.
Alpha, beta, gamma, and lambda are all Greek alphabets.
If mutations continue to occur, one day there will be omega mutations.
But, why do these mutations occur, and how do they affect the human body?
[What is it?] Why do viruses mutate?
Viruses cannot be numbered by replicating themselves while standing alone.
It can only reproduce by infiltrating living cells.
Since cells don't just come in, viruses need some kind of device.
On the surface of the virus, things called 'spike proteins' sprout.
This serves as the key that opens the door to the cell.
Human cells have something called 'receptors'.
It is easy to think of it as a lock on the door of a cell.
When a virus approaches a cell and pushes a spike protein that matches its receptor, the cell's door opens, allowing the virus to enter a human cell and replicate itself.
The cloned viruses come out of the cell and infect other cells again, and the process repeats.
When these infected cells multiply, our body causes symptoms and becomes ill.
However, the process by which a virus replicates itself and makes countless copies is not as precise as the process in which human cells divide.
Since I make a lot of rough copies quickly, errors are increasing in the process of repeating the genetic information copy.
Think of a game of telling a story.
It is similar to saying that the words are similar at first, but when they reach the end of the line, they become completely absurd.
The problem is, these mutations fool the body's immune system.
When a virus attacks cells in our body, our immune system produces 'neutralizing antibodies' to neutralize the virus.
Neutralizing antibodies are customized for each virus.
(Neutralizing antibodies to neutralize the hepatitis virus and neutralizing antibodies to neutralize the cold virus are made differently.) The neutralizing antibody overwrites the key (spike protein) possessed by the virus, preventing the virus from opening the door to our cells.
However, the mutant virus has a spike protein that can deceive the existing neutralizing antibody and unlock the door of our cells.
Let's think about it this way.
The automatic crime prevention system said, “The masked guy with his eyes closed is a robber.
Catch me.”, but the robber appears with a mask covering his mouth instead of a mask covering his eyes.
The security system does not recognize this intruder as a 'robber' and allows it to pass through.
That's what happens in our bodies.
Viruses invade cells in our body, then destroy those cells and turn them into a virus replication factory.
So what should our immune system do?
The factory must be destroyed so that the situation does not get worse.
Immune cells protect our body by killing virus-infected cells.
If our body's immune system knows the identity and tactics of the intruder (virus), it will successfully defeat the virus' offensive.
But, what if the virus you see for the first time attacks with a tactic you see for the first time?
At least in the beginning, you can only be helpless.
Vaccine goal: to prevent hospitalization or death even if infected
This is the case with the COVID-19 virus and its variants that are afflicting the world right now.
Vaccines are what trains the body's immune system to fight these new viruses.
The function of a vaccine is to 1) prevent the cells from being infected with the virus as much as possible and 2) make the immune cells handle them well even if some cells are infected, so that even if we become ill, our symptoms do not worsen or die.
If so, are vaccines such as Pfizer, AstraZeneca, and Moderna, which are currently widely used in countries, effective against mutated viruses?
It seems to be working, at least if you look at the situation in countries such as the United States and the United Kingdom so far.
In the United States, where the highly contagious delta mutation accounts for 52% of new infections, it has been shown that when the vaccine is completed (two weeks after the second dose), there is little chance of infection.
CBS News reported on the 10th local time that 99.7% of all new infections were people who had not completed vaccination.
[Important Fact] US and UK study results: vaccines are also effective against delta mutations
In the UK, where the AstraZeneca vaccine was developed, more than half of the population received two doses of the vaccine, and according to Public Health England, the recent death rate of COVID-19 patients was only 0.085%.
The death rate fell to 1/20th of its peak.
Public Health England (PHE) announced on May 22 that 'It was found that two doses of the vaccine showed a very high protective effect against the delta mutation'.
According to this study
- With the Pfizer vaccine, 88% of the symptoms of the delta mutation were prevented two weeks after the second dose.
The prevention rate for alpha mutations (formerly British mutations) was 93%.
- The AstraZeneca vaccine showed a 60% prevention rate of delta mutation symptoms after the second dose was administered.
The prevention rate of symptom occurrence for alpha mutation was 66%.
- For both types of vaccine, the prevention rate of delta mutation symptoms was 33% after a few weeks after the first vaccination.
(After the first inoculation, the symptom prevention rate for alpha mutation is 50%)
At this point, you might think that AstraZeneca is worse than Pfizer, but PHE (England Public Health Agency) has given a clue that it cannot make such a judgment hastily.
According to the antibody profile data formed after vaccination, it takes longer than Pfizer for the effect of AstraZeneca vaccination to reach its peak. will be.
PHOTO: Matt Hancock, then British Health Minister.
Regarding the announcement on May 22, he said:
“More than 20 million Britons (more than a third of the population) now have a significant degree of protection against new mutations.
And that number is growing by hundreds of thousands every day as more people get their second dose."
“Pfizer-AZ, the rate of prevention of severe cases due to delta mutation will be higher”
PHE also said that although data are not yet available to officially state the prevention rate, the effectiveness of Pfizer or AstraZeneca (AZ) vaccines in preventing gastric-severeness or death due to delta mutations is greater than the prevention rate for the onset of symptoms. said to be much higher.
This part is important.
Vaccination is to prevent serious illness or death, and for this purpose, both Pfizer and AZ show a very good effect
.
This means that if you can get the AZ vaccine, it is advantageous to not avoid it and get it.
SBS medical reporter Dong-chan Cho (specialist) introduced that as various mutations are rampant, the effectiveness of vaccines using real viruses like the AZ vaccine is receiving new attention.
mRNA vaccines such as Pfizer Moderna have a strong ability to generate a lot of neutralizing antibodies to specific viruses in our body.
(As explained in the figure above, neutralizing antibodies make the virus use the key that opens our cells.) However, the conditions for neutralizing antibodies to work are difficult.
When a mutant virus enters, the existing neutralizing antibodies do not function properly.
So, when the number of infected cells increases, immune cells must step forward to treat the infected cells, and research results are coming out that the AZ vaccine has the power to activate these immune cells.
Therefore, even in the United States, which is not yet vaccinated with the AZ vaccine, there is an opinion that boostershot should be vaccinated with the AZ vaccine in order to increase the ability of those who have completed Pfizer vaccination to respond to mutations.
* Listen to Dong-chan Jo's expert reporter
(Vaccine-related explanations from the 14th squad. SBS podcast 'Choose Newsroom', 289 episodes) The
Korea Institute of Health and Medical Research and the Korean Medical Association's rapid review study show that AstraZeneca, Pfizer, and Moderna When vaccination was completed, it was confirmed that it was effective in preventing symptomatic infection, hospitalization and death against all mutated (alpha, delta, beta, gamma) viruses.
According to this domestic study, hospitalization and death due to mutant virus infection could be reduced by 78 to 96% when a single inoculation was completed.
Completion of up to two doses was found to reduce the risk of hospitalization and death by 86-96%
The effectiveness of vaccines made in China to prevent mutant infection is questionable
However, looking at the cases of each country, it seems that the Chinese-made Sinovac vaccine has a problem in its ability to respond to mutations.
Singapore mainly vaccinates with Pfizer, but it has also approved the emergency use of Chinese-made Sinovac.
At 24 private hospitals in Singapore, mainly Chinese residents were vaccinated with Sinovac.
However, on the 1st, the Singapore government required that those who received Sinovac receive a corona test before attending various gatherings.
Analyzing the infection cases, it is said that the effectiveness of preventing the delta mutation of cynovac cannot be confirmed.
Indonesia is a representative country that relies on vaccines made in China, and the recent spread of the mutated virus has caused an increase in severe cases and deaths.
In particular, 90% of the medical staff who were the first to receive the vaccine were vaccinated, and 10 of the 26 medical staff who received the Sinovac twice this month died from Corona, the Wall Street Journal (WSJ) reported on June 27.
Photo: Funeral workers in Indonesia whose death toll is skyrocketing due to the recent delta mutation spread.
Indonesia has emerged as a new epicenter of COVID-19 as the number of new infections has surged due to the spread of delta mutations since early last month.
According to CNN, the number of new cases has increased more than 10 times compared to the beginning of last month.
The number of daily deaths also increased tenfold compared to the beginning of June.
Before the third booster shot in developed countries starts in earnest, enough vaccines need to be brought into Korea.
So, the problem is getting enough effective vaccines.
It is not enough just to declare that it has 'contracted' enough to meet the entire population of Korea.
The plane carrying the vaccine must actually arrive at Incheon International Airport.
Even though President Moon Jae-in has promised to secure 20 million people for Moderna, the situation in the future cannot be reassured given that reservations have been disrupted due to supply and demand instability in the past few days.
What should be noted in this regard is the discussion of additional booster shots coming from the US, UK, Israel, etc.
Photo: Israel begins 3rd vaccination
Israel has already entered the third dose (booster shot).
The United States is still cautious, saying that raising the completion rate of the second vaccination is a priority, but if there is a boom in securing booster shots even in the United States, which has a population of 330 million, the supply of vaccines in Korea is bound to be even more twisted.
This is why it is necessary to mobilize all national capabilities to ensure that the contract volume actually arrives in Korea.
(Composition: Senior Correspondent Lee Hyun-sik, Reporter Jang Seon-i, Kim Hwi-ran Editor / Designer: Myung Ha-eun, Lee Ji-soo)