Associated Press (Photo) A park in San Francisco, USA, has a circle for “social street maning.” Scientists say the future of Corona19 is uncertain.

“It has been a year and six months since corona19 pandemic began in June 2021. The speed has slowed down, but the virus is still spreading. Intermittent blockades (restrictions on movement) have become new normals. Even though the vaccine has been approved six months later, supply is sluggish. The number of people infected worldwide has surpassed 250 million and the death toll has surpassed 1.75 million.”

It is one of the upcoming corona 19 scenarios for infectious disease scientists, recently published in the international scientific journal Nature. Nature has published a comprehensive article analyzing 18 articles on the situation and prospects of Corona 19 published in various journals. Nature said experts had a wide range of corona19 prospects, but agreed that the future of Corona 19 was uncertain.

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What’s the current situation? : 10.5 times the actual number of infected persons and 1.5 times the number of deaths

Seven months after the World Health Organization first officially notified the World Health Organization at the end of last year of a new outbreak of infectious diseases, the number of corona 19 infections worldwide has reached 20 million, and the death toll has surpassed 700,000.

“Nature” currently has two main types of national fan-demic situations. The first is a strong blockade to curb the spread of infections, and now countries are easing restrictions on movement, depending on the situation. Countries like China, New Zealand and Rwanda. Second, the blockade is not strongly implemented or released early, and the number of patients is still soaring. The United States and Brazil are the main examples. According to this standard, Korea belongs to the former.

The latter group is a country that scientists are concerned about. South Africa, currently ranked fifth in the world with 550,000 confirmed numbers, is expected to reach more than one million in August and September, and a cumulative number of patients in November to reach 1.3 million. Of course, there are signs of hope. Even after the blockade has been lifted, hand washing and mask ingestion are maintained in everyday life. Researchers at Imperial College London examined 53 countries that lifted blockades and found that the number of people infected did not increase significantly than expected as people’s lifestyles changed.

ED JONES via Getty Images Visitors to the National Museum of Korea wait for entry wearing masks. July 23, 2020.

Researchers at The University of Anhembimorumbi university in Brazil looked at 250,000 mathematical models related to social distance, and found that 50-65% of the population could prevent a surge in infected people over the next two years if they wear masks in public places and step-by-step ease social distance spacing every 80 days. To do this, the researchers emphasized that the culture of contact with people must be changed. Nature said it’s good news that actions without vaccines can produce these results.

Similar studies have shown in the United States. The death toll in the United States, the world’s largest infected country, is now expected to reach 29,501, up from 134,854 by December. However, according to an IHME simulation at the University of Washington, 95% of Americans use masks when they are out and about, reducing the number of future deaths by 49 percent. In this case, the total death toll is 228,721.

Scientists have emphasized that where the number of new infections is on the decline, rapid diagnostic scans, quarantine of infected persons, and tracking of infected contacts are the best responses. How much contact tracking should be done to effectively curb corona 19 proliferation? Researchers at the London School of Hygiene and Tropical Medicine (LSHTM) have published a modeling study that says 80% of contacts should be able to be tracked within a few days. In reality, however, this is virtually impossible if thousands of new infected people are released per week. If so, the actual number of infected people is much higher than the official statistics. Based on analysis of diagnostic test data from 86 countries, MIT researchers estimated that the number of infected people worldwide would be 10.5 times higher than official statistics and 1.47 times more deaths.

Kim Hong-Ji / Reuters scientists predicted that Corona19 would be seasonal.

After the fall? : Cold dry air danger… Lower the likelihood of group immunity

Experts predicted that corona19 virus, like other respiratory viruses such as influenza, would be seasonal. As a result, temperatures were expected to drop again over the summer. Professor Akiko Iwasaki, of Yale University School of Medicine, said, “Cold, dry air increases the infectious power of respiratory disease viruses, and drinking dry air can damage the immune defenses of the respiratory tract.” When the weather gets colder, it’s also a risk factor to spend longer indoors. In poorly ventilated indoor spaces, the likelihood of virus contact increases.

According to simulations by researchers at the University of Basel in Switzerland, seasonal changes are likely to affect the spread of the virus, which can worsen the conditions of infection in the northern hemisphere this winter. Corona 19 may be in vogue every winter.

In this case, adults who have had corona 19 may have a less risk of infection. However, this depends on how long the immunity of the patient recovers. If corona 19 and flu, RSV (cell fusion virus) and the like occur sit in overlap, the situation may be worse.

Corona virus that infects humans is all seven species, including four species that cause a common cold. Who has been infected with other corona viruses? It is not yet clear. In May, the international journal Cell published a cell culture experiment with the corona19 virus, and a study showed that one coronavirus antibody could be combined with another coronavirus, but did not deactivate or neutralize the virus. However, in the last 4 days, science has shown that people with immune T cells after suffering from a cold have some immunity to coronavirus.

To end Corona 19, you need to get rid of the virus or have the immunity of so many people. The latter is called collective immunity. For collective immunity to succeed, immunity must be developed in 55-80% of the population. However, there is a long way to go before collective immunity can be realized. A study of 11 European countries showed that as of May 4, corona 19 infection rates were only 3-4%. In mid-May, when more than 150,000 deaths occurred, the U.S. Centers for Disease Control and Prevention sampled thousands of serums, and antibody retention was only 1 to 6.9 percent per region.

Lisa Maree Williams via Getty Images A shopping mall employee in Sydney, Australia, is doing a ‘social street’ August 6, 2020.

What after 2021? : Vaccine supply rate and duration of immunity are key

The development of pandemic after next year depends on the rate of vaccine supply and the duration of immunity. The immunity of measles and polio vaccines has been around for decades, but vaccines such as influenza disappear over time.

In a paper published in Science in May, Researchers at Harvard predicted that corona 19 would come back every winter, even if the first pandemic passed. The refore, the researchers recommended that persistent or intermittent social distance scepeople are needed by 2022.

The duration of the immunity of corona 19 antibodies is not yet known by scientists. One study found that neutralizing antibodies lasted up to 40 days for patients recovering. Other studies have estimated that antibody levels decrease after weeks or months. If corona 19 follows the pattern of sars (severe acute respiratory syndrome), the antibody will be maintained at a high level for five months and gradually reduced over 2-3 years.

Of course, antibodies are not the only means of immune protection. Non-cells and tee cells also have a virus-fighting force. However, Nature pointed out that they have not yet figured out exactly their specific role.

Without vaccines or persistent immunity, Corona19 would be endemic, such as malaria. If the virus causes only short-term immunity, such as cold coronavirus (OC43, HKU1), which lasts for about 40 weeks, corona19 can be exposed to infection risk, such as annual events. The University of Minnesota Center for Infectious Disease Research (CIDRAP) report, based on the past eight influenza epidemics, points out that the number of corona 19 infections will gradually decline over the next 18-24 months from highs and lows, or show a pattern of infection surges without any apparent ups and downs.

Nature, however, emphasized that these are only speculative scenarios. Corona 19 is an unprecedented epidemic that has shown a pattern different from the influenza of the past.

Heo Ran / Reuters Professional Baseball LG Twins vs. Doosan Bears at Jamsil Baseball Stadium in Seoul, where spectators are on the lookout for a national ceremony. July 26, 2020.

Where to develop vaccines? : 6 clinical phase 3… 12 clinical phase 2

Corona 19 cannot be ruled out if immunity is permanently maintained. Fortunately, in this case, the virus can be self-destructed in 2021 without a vaccine. However, if immunity is around two years, Corona 19 could return in 2024.

However, this scenario did not take into account the development of vaccines. Nature pointed out that this is an unrealistic scenario, considering the tremendous efforts of the world’s major countries in vaccine development. According to the World Health Organization, there are currently 26 vaccines under clinical trials. Six of these are in the final phase of clinical phase 3 trials and 12 are in the clinical phase 2 phase. If the trend is right now, it is likely that the first vaccine will be released in a few months.



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