"Omikron" appeared for a month, what happened to the world?

Only when global vaccination rates reach a certain level will outbreaks turn into endemic epidemics confined to some regions.

Since the South African Ministry of Health first reported the new strain of the new coronavirus, Omicron, on November 24, as of December 24, in just one month, Omicron has swept 110 countries and regions around the world.

As early as early November, there were 10 confirmed cases of the mutation worldwide, in Botswana, South Africa and Hong Kong, China. Botswana in southern Africa was the first to detect three confirmed cases on 11 November and six cases in South Africa on 14 November. Case 1 in Hong Kong, China, is a South African returning man who tested positive for a routine nucleic acid test on 13 November.

Judging from these data, It is highly likely that Omi kerong has appeared in October, but it has not been discovered.

The first month of Omikron

After the appearance of Omikerong, the average daily new cases in South Africa jumped from 200 to 300 to 20,000 in one month.

The test-positive rate is more than 30% – meaning there are still a large number of untested infected people in the community.

On December 13, South African President Ramaphosa also tested positive for COVID-19. What is the fatality rate of Aomi Kerong? While confirmed cases rose sharply, deaths fell sharply from September to remain low in November. From this data, the fatality rate of Omikeron should not be higher than that of Delta.

At present, in 110 countries and regions around the world, the symptoms of infected people imported from outside The Semikron are relatively mild, and the vast majority of these people are in good health and healthy enough to travel internationally.

The Indian Ministry of Health said on the 21st that a total of 200 cases of Omiljung strain infection were found in 12 states, of which 77 confirmed cases have been cured or discharged from the hospital. Cases of Infection of the Omiljung strain in India almost doubled in one week, but there have been no related deaths. And about 80% of infection cases do not develop symptoms.

According to the data released by the US Centers for Disease Control and Prevention on the 20th, the Aumeticron strain has become the dominant strain transmitted in the United States, accounting for about 73% of the new cases.

On 1 December, the first case of Infection with the Omikejong strain was detected in the United States. As of Dec. 21, the strain had been found in 48 U.S. states, and it took less than a month for Amiqueron to successfully replace Delta in the United States. On December 24, the average number of new infections in the United States exceeded 180,000 per day, and it is expected that the next few weeks may break the record of daily increase in confirmed cases in the United States.

The UK has "broken the record". According to the data released by the British government on the 24th, the average daily number of new confirmed cases exceeded 120,000, setting a record for the highest outbreak of the epidemic. Compared with 2 months ago, the number of daily confirmed cases has almost tripled.

Chinese mainland the first imported case of Omikerong strain was detected in Tianjin on 13 December. At present, Hong Kong, Shenzhen, Changsha, Guangzhou, Changsha and Taiwan have all appeared. In the context of the Global Sweep, it is only a matter of time before cities with international flights are breached, which will definitely bring unprecedented pressure to "dynamic zeroing".

The history of epidemic prevention and control in the past two years shows that biological prevention and control is effective with physical prevention and control, but for new variants such as Aomi Kerong, whose transmission power has increased and its pathogenicity has weakened, the focus of prevention and control can be appropriately shifted to the prevention and control of pneumonia caused by infection, so that social costs will be greatly reduced.

Looking back at the Delta strain, from the discovery in India to the time it was breached in Guangzhou, the interval was 4 months. But this time, the Omiljung strain was introduced into the country in only one month.

"Christmas gifts"?

After the discovery of Omicron, countries announced tightening of travel restrictions. At the same time, many Western medical experts have called the variant a "Christmas gift".

On November 29, German Federal Health Minister Karl Lauterbach said that Aumikrondo caused mild illness, so it would be a Christmas gift for countries and may even accelerate the end of the epidemic.

Less than a month later, on 21 December, Kruger, director of WHO's Regional Office for Europe, publicly stated that "we can foresee a new storm coming." Omikeron will become a mainstream strain in more European countries in the coming weeks, pushing healthcare systems to the brink of collapse. ”

The difference in the above views can be summarized as: Will the new crown "flu"?

On November 19, 2021, the U.S. Centers for Disease Control and Prevention updated the COVID-19 infection rate and hospitalization rate among people over the age of 12. For Delta mutant strains, vaccination reduced infection rate by 3.45 times, hospitalization (severe illness) rate by 2 times, and risk of death by 7 times. Compared with the first half of the year, the protection of vaccines has been reduced a lot.

COVID-19 is by no means a pandemic. According to the U.S. Centers for Disease Control and Prevention, the case fatality rate for seasonal influenza in all age groups is 0.1 percent and in the children group at 0.004 percent. Even after full vaccination, the CASE FATALITY RATE OF COVID-19 is still 6 times that of influenza, and is more pronounced in the elderly.

This winter's infectious disease season is only a third past. Omi kerong superimposed Delta, and among the populations who had been fully vaccinated, there was no sign of a significant decline in the total number of infections.

Experts agree that the peak of the fifth wave has begun. When do peaks appear? "Peak width" for a few months? Does the vaccine still work? Is it still too late to get a booster injection? We still don't see when we can remove our masks.

It will not be the last mutant strain

The human adaptability of Omikeron surpasses that of previous variants, importantly because it was screened from immunosuppressed populations in southern Africa.

When a large number of people are vaccinated, it forces the most escaping virus variant to win. In the past year, although no variant has been able to completely ignore the vaccine, most of them have shown low sensitivity to vaccines.

For example, a report from the state of New York showed that the vaccine's protection against all COVID-19 variants decreased from 91.7 percent to 79.8 percent between May and July at the time of the Delta strain epidemic.

A multi-agency study by the WHO Collaborating Centre for Infectious Disease Modelling shows that the proportion of people infected with Thermo-Kerong visiting hospitals and hospitalizations by 40%-45% compared to those infected with the Delta mutant strain.

Omi kerong has multiple mutations that reduce the neutralization activity of antibodies, resulting in a stronger immune escape ability, but existing vaccines are still somewhat useful. It is most likely not the last variant, and there may be mutant strains that are completely "immune" to existing vaccines in the future, but if there is, its pathogenicity will certainly be weaker than that of Omikeron.

In fact, most variants existed before mass vaccination, but after widespread vaccination, these variants, which have a strong immune escape ability, gain a transmission advantage.

At present, it is still impossible to stop the pace of immunization and injections. Immunization is also the most practical, costly and fastest way humans can take to deal with the new crown virus.

Anti-coronavirus antibodies, which account for a small proportion of the population, cross-protect the population from covid-19. Southeast Asia and Africa have the lowest mortality rates in this global epidemic, which may be due to this weak cross-protection, in this sense, the existing vaccines, although there are differences in protection rates, are effective in reducing mortality.

What happens next?

A recent study from the University of Cambridge in the United Kingdom found that Omexron may be less effective at attacking the lungs compared to earlier novel coronavirus variants. Another study showed that Omikeron did not cause cell death for up to a week in vitro cell culture. It shows that its lethality to human cells has been greatly reduced.

Research from the University of Hong Kong showed that Opmi kerong infects human bronchi 70 times faster than Delta, which is why it spreads so fast. However, Omiljung is 10 times slower to infect the alveoli in lung tissue, and prevention and control is becoming more and more difficult, while pneumonia is getting lighter.

Chinese mainland the most likely way to appear in the territory of Omicron is expected to be air import. Due to the strong spread power, it will be a big test for the prevention and control system in various places. In fact, due to the stricter physical prevention and control in many countries in Asia, there is more social isolation, and there is a high probability that medical resources will not collapse. In addition to China, Japan, Israel, and Singapore may also be honor students.

India is one of the countries with the worst COVID-19 outbreaks. At its peak in May this year, the average number of new confirmed cases and deaths per day was about 400,000 and 5,000. However, since then, the relevant data have dropped sharply, and in December, the average number of confirmed cases and deaths per day is only about 2% and 10% of the peak period, respectively.

Full vaccination rates in India are currently around 40 percent, while antibody positivity in New Delhi is 97 percent. Antibodies produced by the natural infection of the Delta strain, together with vaccination, still have a protective effect on the Ami kerong strain. Optimistically, infection and mortality in India will not rise much.

Officials in the United States have warned of a possible 1 million new cases a day. It is still possible to repeat the mistakes of last winter: the surge in the number of medical patients has led to the collapse of medical resources. Europe is expected to be in the same situation as in the United States.

On December 24, a study in the journal Nature found that at least three variants of the new coronavirus had been found in wild white-tailed deer in the United States, and white-tailed deer had been infected with the new coronavirus for a long time. It is estimated that there are about 30 million white-tailed deer in the United States.

This means that COVID-19 has established a new maintenance host outside of humans. It is highly likely that Omikeron will infect the white-tailed deer population in the short term, and multiple mutant strains coexist in wild animal populations at the same time, which may open up new avenues for virus evolution and greatly increase the difficulty of long-term prevention and control.

Source: Medical community

Editor-in-charge: Ling Jun

Proofreader: Zang Hengjia

Plate making: Xue Jiao