With a sharp drop in new confirmed cases and a case fatality rate of only one-tenth of Delta, is Omicron really the terminator of the new crown?

Reporter | Yuan Yiming

Edit | Xie Xin

On January 11, a research paper titled "Clinical outcomes among patients infected with Omicron (B.1.1.529) SARS-CoV-2 variant in southern California" was published on MedRxiv, a medical paper preprint website. Based on an analysis of 52,297 Opichron cases and 16,982 Delta cases, the ICU hospitalization rate in The Semikron case was 0.26 times that of Delta cases (about 1/4) and the mortality rate in Omikeron cases was 0.09 times (about 1 in 10) of Delta cases.

The findings also showed that among symptomatic hospitalizations, the median estimated length of hospital stay for Delta cases was 4.9 days, and the median length of hospital stay in Omikejong cases was 3.4 days less than that of Delta cases, i.e. a 69.6% reduction in length of hospital stay.

However, the article also suggests that the study has limitations, that is, the clinical and epidemiological data of infected people are derived from the Kaiser Permanente Medical Group's Southern California Health Care System, and the testing opportunities for this member may be different from that of the general population, so the hospitalization rate of Omilon cases and non-Omilon cases in the study may not be at the same level as that of the general population; differences in previous infection and vaccination rates between members and the general public may also affect the portability of the effect size estimated by the study.

But it's not the only study that has shown a decline in the mortality rate from confirmed cases in Olmiqueron, with a new study shared by CDC Director Varensky on Jan. 13 showing that compared to the risk of contracting the Delta variant, people infected with Omikeron were 53 percent less likely to be hospitalized asymptomatic, 74 percent less likely to be admitted to an intensive care unit, and 91 percent less likely to die.

Chang Rongshan, a virology expert, told interface news reporters that in the case of continuous evolution of the virus and the enhancement of immune escape, the decline in case fatality is in line with the general law of transmission in epidemiology, but the rate of decline is unlikely to reach a low level of only one-tenth of the previous level in a short period of time.

According to its analysis, the most likely reason why the case fatality rate of Omi kerong has dropped so quickly is that the new crown vaccine has played a role, and the new crown vaccine can still greatly reduce the severe illness rate and mortality rate even if it does not protect the human body from infection. Chang Rongshan also believes that compared with two years ago, the medical community has now accumulated a lot of experience in treating new crown patients, which can achieve early detection and early treatment, which is also one of the reasons for reducing patient deaths.

In addition, several areas of the United States that were first hit by the Omikejong virus also show signs of slowing new cases.

CNBC News reported on January 17 that the epidemic data compiled by Johns Hopkins University in the United States shows that in New York, the seven-day average of new cases recognized daily has been declining since the record high of 85,000 new cases per day reached on January 9. In a few seven days at the end of December 2021 and early January 2022, new cases doubled, but there has been a sharp drop since last week, now averaging 51,000. New York State Department of Health data shows that the average daily new cases in New York City have fallen by 31 percent over the past week.

However, Chang Rongshan believes that the decline in the number of new infections after reaching the peak is not related to TheOmilon itself. Specifically, not everyone is susceptible to COVID-19; current data show that around 10% of people are not easily infected even without any protective measures, vaccinations, and masks, and no less than 40% of people do not have any symptoms even if they are infected with COVID-19.

Therefore, the first wave of the new crown virus will be infected by those who are the most susceptible, after 2 years of infection time, many of the remaining people are relatively unsentiable people, and the infection rate will not be as fast as the first wave of infection. A decline after peaking is in line with epidemiological laws and does not prove that the infection rate of Omikeron is low.

It is also worth noting that the current social distancing policy in the United States is very strict, and the physical protective barrier established is also a significant reason for the decline in the peak number of infections, because the spread of Omilon is about three times that of the early strains.

At present, there are constant calls at home and abroad for "the end of the new crown in 2022". On January 15, Zhang Wenhong, director of the National Center for Infectious Diseases And director of the Department of Infectious Diseases at Huashan Hospital affiliated to Fudan University, said in an interview with CCTV News Relativity that after the next year, whether it is the level of herd immunity, the immune barrier established through vaccines, and then the listing of new crown treatment drugs, it means that "this may be the last 'cold winter'".

WHO Director-General Tedros Adhanom Ghebreyesus also said at a press conference on December 29, 2021, that 2022 could end the severe period of the new crown pneumonia pandemic.

However, Chang Rongshan believes that the above conclusions are too optimistic, and told the interface news reporter that in the case of continuous mutation of new coronavirus strains, the protection rate of new crown vaccines is also declining, and the best time for the protection period of new crown vaccines is the first three months after the completion of the vaccination procedure, and the protective efficacy will continue to decline between the third and sixth months, and the protective effect after the sixth month is minimal. In addition, in the future, there will be the emergence of new mutants with stronger immune escape ability. For the above reasons, it does not believe that 2022 will be the "final year" of the new crown.

Therefore, it suggests that although the pathogenicity rate of Aumechjong has declined today, the public still cannot relax the awareness of prevention and control, and the susceptible people of the new crown such as the elderly, high-risk exposure groups such as customs, isolation point staff, etc. still need seasonal vaccination of the new crown.