Vaccine effect on long-term sequelae, potential of the world's first "DNA vaccine": new coronavirus and the world now (September)

As of the end of September 2021, more than 2.5 billion people, or 33% of the total population, have completed vaccination with the new coronavirus (SARS-CoV-2), and the cumulative number of vaccinations has exceeded 6 billion. However, breakthrough infections have been reported in which the virus is transmitted even with vaccination due to the spread of the delta strain, which has tremendous infectivity, and the decrease in the amount of antibody derived from the vaccine.

Although the vaccine is still very effective against aggravation and death, the preventive effect of the infection itself has diminished. In response to this situation, wealthy countries such as Israel, the United States, the United Kingdom, and Europe have older people aged 65 and over, teachers and health workers, workers at high risk of infection, and underlying illnesses. The third booster vaccination has been started by people.

Under these circumstances, President Felix Tsusisekedi of the Democratic Republic of the Congo represents the continent of Africa, and in order to protect Africa and the world from the new coronavirus infection (COVID-19), sustainability from the international community in terms of both public health and economy. Claims the need for support and cooperation. More than 82% of the world's vaccines are given in rich countries, while low-income countries make up only 1%. Of the 1.38 billion population in Africa, less than 4% have been completely vaccinated so far.

On the other hand, in countries where the vaccine has been distributed to everyone who wants it, it seems that it is inconvenient to remain unvaccinated, such as requiring the submission of a weekly negative certificate if vaccination is refused. Rules are beginning to be introduced.

France, for example, warns that medical, long-term care and fire department staff must quit their jobs if they have not been vaccinated at least once by September 15. In fact, about 3,000 people have refused vaccination and have been suspended. In New York, the United States, medical workers have begun to be dismissed or suspended due to vaccination refusal. United Airlines is also in the process of dismissing about 600 unvaccinated workers.

It is Singapore that has begun to see the future of coexistence rather than virus eradication. The metropolis, with a high vaccination rate of 80% of the total population, faces a record increase in COVID-19 infections. However, even if the number of newly infected people per day reached a record high of 1,647, the average number of deaths per week is about three. COVID-19 is considered endemic in Singapore, as more than half of the infected are vaccinated and the number of severely ill patients and deaths is kept very low.

In Japan, the fifth wave of Delta stocks converged at once, and the state of emergency issued to 19 prefectures was completely lifted on the 30th. Vaccination is progressing at a rapid pace in Japan as well, with about 60% of the total population currently having two vaccinations and more than 70% having at least the first vaccination.

In September 2021, new evidence was released for the efficacy rate of the third booster dose, the incidence of sequelae after breakthrough infection in vaccinated individuals, and strong evidence that SARS-CoV-2 is of natural origin. Let's look back on the new coronavirus and the trends in September around the world.

The infection prevention effect of the third inoculation is 91% compared to the Delta strain.

An Israeli study conducted a study to test the effectiveness of the third booster shot. The study extracted data on 1,137,804 elderly people over the age of 60 who completed Pfizer vaccination at least 5 months ago between July 30 and August 31, 2009. In addition, we compared the proportion of confirmed and severe COVID-19 between the group (booster group) 12 days or more after receiving the third booster and those who did not (non-booster group). ..

As a result, it was found that the risk of infection with the Delta strain was reduced by about 11 times and the risk of severe illness was reduced by about 19 times compared to the second dose. The effective rate of infection prevention is 91%, and the prevention of aggravation is 95%.

Moderna vaccine is more effective against Delta strains than Pfizer

The Centers for Disease Control and Prevention (CDC) reported the presence or absence of vaccination and its types in 32,867 adult patients from June to August 2009, when Delta strains were the majority in the United States. According to the report, the probability of emergency outpatient visits was the lowest, and the highest efficacy rate for Delta strains was made by Moderna (92%), followed by Pfizer (77%) and Johnson & Johnson (65%). ) Continued. The effective rate of hospitalization (severe) prevention was higher in the order of Moderna (95%), Pfizer (80%), and Johnson & Johnson (60%).

Vaccines also halve the onset of the sequelae "Long Covid"

A large study of the long-term sequelae of COVID-19, "Long Covid," conducted in the United Kingdom showed that the vaccine was effective in preventing sequelae. People with breakthrough infections despite two vaccinations may have a 50% reduction in the incidence of long covid symptoms, which last for more than 4 weeks after a positive reaction, compared to unvaccinated individuals. It is said that it became clear.

The study, published in the medical journal The Lancet, found that more than 1.2 million adults were vaccinated once and 971,504 health status twice between December and July 2008. Was tracked. Only 0.2% (2370) had breakthrough infections after two vaccinations. Of these 592 patients who continued to provide data for more than a month, 31 (5.2%) developed long covid. In contrast, the incidence of sequelae in the unvaccinated group was about 11%.

DNA vaccine "ZyCoV-D" approved in India

In India, an emergency use of a new DNA-based coronavirus vaccine has been approved. The vaccine "ZyCoV-D" produced by Indian pharmaceutical company Zydas Gadilla contains a circular DNA called a "plasmid", which is coded with information such as the spike protein of SARS-CoV-2. Has been done. When the plasmid enters the cell nucleus, it is converted to mRNA and translated into spike protein. The body's immune system responds to this protein to create immune cells.

This vaccine requires the second and third doses on the 28th and 56th days after the first dose, but in clinical trials involving more than 28,000 people, it may be 67% preventive. It has been confirmed (60 out of 28,000 people developed COVID-19 in the placebo group and 21 in the vaccinated group). Although less effective than other vaccines that have already been approved, this efficacy rate is against Delta strains, which is simpler than other vaccines tested during the epidemic of less infectious conventional strains. It is said that it cannot be compared with.

The advantage of DNA vaccines is that they are easy to manufacture and the final product vaccine is more stable than the one using mRNA. On the other hand, unlike the mRNA vaccine, which only needs to reach the cytoplasm, it needs to reach the cell nucleus. Therefore, DNA vaccines have not previously elicited a strong immune response in clinical trials, lagging behind RNA vaccines. To solve this problem, ZyCoV-D uses a technique to deposit the vaccine under the skin rather than deep in the muscle tissue. Since there are many immune cells under the skin that eat and process foreign substances such as vaccine particles, DNA can be captured much more effectively than intramuscular injection.

This vaccine is characterized by high-speed injection into the skin without using a needle, and is permitted for use over 12 years old. Since it does not use a syringe, it is also useful for inoculating children.

INFORMATION INFORMATION

Special feature: The battle between the new coronavirus and the "world"

How will the global spread of the new coronavirus change the world? We will deliver the latest information from the unique perspective of "WIRED", such as what you need to know now, the current state of research and development, and the impact on society and the economy.

Bat-to-human transmission occurs frequently

As the world pursues the origin of SARS-COV-2, preprinted papers suggest that bats are rich in viruses that can infect humans in China and Southeast Asia. ing. Of these, two are the viruses that have spread worldwide over the past 20 years. SARS-CoV, which caused severe acute respiratory syndrome (SARS), and SARS-CoV-2, which is the causative virus of COVID-19.

A small study conducted prior to the outbreak of COVID-19 revealed that some people in Southeast Asia had antibodies to the SARS-related coronavirus. Combining these data with data such as how often bats are encountered and how long antibodies stay in the blood, researchers found that about 400,000 bat-derived viruses infect humans annually in the region. It is estimated that it is. However, these viruses are often poorly adapted to humans, so the duration of infection is short and does not lead to human-to-human transmission. In addition, even if the virus can spread fortunately, it may remain in a small isolated community and will not spread.

Nonetheless, this study shows that human-bat contact is much more common than expected, and bat-derived pathogens can infect humans and pets and livestock that are closely associated with humans. It turns out that it's only a matter of time. Local people have many opportunities for contact, such as digging bat droppings from the cave and using it as fertilizer or feeding on bats.

The study maps the habitats of 23 species of bats carrying the SARS-related coronavirus and superimposes them on human settlements to identify potential infectious hotspots. As a result, it was found that the risk of bat-to-human transmission is highest in southern China, Vietnam, Cambodia, and Java Island in Indonesia.

Are there many "relatives" of the new coronavirus in Southeast Asia?

A study of bats inhabiting China and Laos found that Southeast Asia is a potentially dangerous virus hotspot similar to SARS-CoV-2.

Scientists have found three viruses in Lao bats that are more similar to SARS-CoV-2 than known viruses. Some of the genetic information about these viruses supports the claim that the virus that caused COVID-19 exists in nature, but there are many coronaviruses in nature that can directly infect humans. Concerns are also rising.

Researchers in France and Laos have taken saliva, dung and urine samples from 645 bats in caves in northern Laos. As a result, viruses showing 95% or more agreement with SARS-CoV-2 were detected in the three species of Greater horseshoe bats, and were named "BANAL-52", "BANAL-103", and "BANAL-236".

Researchers reported last year on another closely related species of SARS-CoV-2 called "RaTG13" found in bats in Yunnan. The virus is 96.1% identical to SARS-CoV-2, and it is believed that the two viruses probably had a common ancestor 40-70 years ago. BANAL-52 shows a 96.8% match with SARS-CoV-2, and all three newly discovered viruses have parts similar to SARS-CoV-2 that are not found in other viruses. That is.

However, the coronavirus derived from Lao bats does not have the furin cleavage site in SARS-CoV-2. A proteolytic enzyme called furin in human cells (especially lung cells and airway cells) recognizes specific amino acid sequences (so-called furin cleavage sites) present on SARS-CoV-2 and other coronaviruses. By cutting it, it helps the virus to invade cells efficiently. Therefore, it is considered that the infectivity among humans differs depending on the presence or absence of a furin-cutting site.

It is still unknown how the virus was transferred to Wuhan, where the first infected person was confirmed, and whether there was an animal that served as an intermediate medium to carry it. However, due to the discovery of a closely related species of SARS-CoV-2 in nature, it is highly unlikely that the cause of the pandemic was "leakage of a virus produced in the laboratory".

In September 2021, the world was forced to take a strategy to seek coexistence with SARS-CoV-2, which continues to mutate with the advent of Delta strains. However, the increased infection-preventing effect of the third vaccination and the incidence of sequelae found to decrease with vaccination provide humanity with time to plan their operations.

A number of pharmaceutical companies around the world are conducting clinical trials of vaccines that carry drugs with antivirals and nasal sprays specifically for the new coronavirus, and the future will not be long before they alleviate the symptoms.

In any case, vaccination and infection prevention will still have to overcome the wave until humans get new medicines.

Science

Unstoppable Delta Strains, Mandatory Vaccination, Introducing Fake Vaccination Certificates: New Coronavirus and Now in the World (August)

Science

"Breakthrough infection" and long-term sequelae "Long Covid" that plague the world: New coronavirus and the world now (July)

Science

How long does the infected person's sense of smell last? How many years will the mRNA vaccine immunize? : New Coronavirus and the World Now (June)

INFORMATION INFORMATION

Special feature: The battle between the new coronavirus and the "world"

How will the global spread of the new coronavirus change the world? We will deliver the latest information from the unique perspective of "WIRED", such as what you need to know now, the current state of research and development, and the impact on society and the economy.

INFORMATION INFORMATION

Under recruitment of WIRED Japanese version "membership" members who can also participate in limited events!

"WIRED SZ Membership" is a member service that delivers a selection of long leads (feature articles) packed with insights for the next 10 years according to weekly themes. The exciting service, which can participate in the weekly members-only event, is running a one-week free trial!Click here for details