The Omikeron mutation has spread to more than 150 countries and regions around the world and is rapidly replacing other strains as the main epidemic strains. According to the US Centers for Disease Control and Prevention website, in the week from December 26, 2021 to January 1, 2022, 95.4% of the new crown pneumonia cases in the United States were infected by the Olmikron variant.
How serious is the infection of the Olmikron variant compared to the previously popular Delta variant? A recent U.S. study answered. On January 11, 2022, local time, MedRxiv, a medical paper pre-print website, published the article "Clinical outcomes among patients infected with Omicron (B.1.1.529) SARS-CoV-2 variant in southern California" ("Clinical outcomes of patients infected with the Semixarong strain in Southern California"). The study showed that the ICU hospitalization rate for Omikejong cases was about 1/4 of Thatta cases and about 1/10th of Delta cases. At the same time, the length of hospital stay in the Omikeron case was 69.6% shorter than that of the Derta case.
Previously, research institutions in the United Kingdom, South Africa and other places have also reported similar results, and the risk of hospitalization in the Case of Ami Kerong is significantly lower than that of The Delta case.
The authors are from the Department of Epidemiology at the University of California, Berkeley School of Public Health, the Research and Evaluation Division of The Kaiser Permanente Medical Group of Southern California, and the COVID-19 Response Team of the U.S. Centers for Disease Control and Prevention. The study was funded by the U.S. Centers for Disease Control and Prevention. It should be noted that the paper has not yet been peer-reviewed.
Screenshot of the paper
The ICU hospitalization rate in the Opichron case is 1 in 4 of the Delta case
The study analyzed clinical and epidemiological data from Covid-19-positive infected people in the Southern California HealthCare System of Kaiser Permanente Medical Group from November 30, 2021 to January 1, 2022.
The researchers used the Cox proportional risk model to compare differences in any hospitalization, hospitalization associated with emerging respiratory symptoms, intensive care unit (ICU) admission, mechanical ventilation, and mortality in cases infected with delta variants and Omiljung variants. The researchers also used parametric competition risk models to compare differences in length of hospital stay in the Opmecreon case and Delta case.
Purple represents delta cases and green represents The Opicon cases. (A) Symptomatic hospitalization of the two, (B) admission to the intensive care unit (ICU) of the two, (C) mechanical ventilation therapy for both; (D) mortality rate of the two. Drawings of the paper
The paper showed that the study included 52,297 Cases of Ami kerong and 16,982 Cases of Delta. 235 (0.5%) of the Omikeron cases were hospitalized and 222 (1.3%) of the Delta cases were hospitalized.
Data analysis showed that among the positive cases detected in outpatient clinics, the ICU hospitalization rate of Theomi kerong case was 0.26 times that of the Delta case (about 1/4); the mortality rate of the Omiljung case was 0.09 times that of the Delta case (about 1/10).
Meanwhile, no cases of Ami kerong received mechanical ventilation; in comparison, 11 cases of Delta received mechanical ventilation during follow-up.
Compared with the length of hospital stay in symptomatic hospitalized cases, the solid line represents the Case of Omicron and the dotted line represents the Case of Delta. Drawings of the paper
Among symptomatic hospitalizations, the median estimated length of stay in Delta was 4.9 days, and the median length of hospital stay in Omilkejon cases was 3.4 days less than in Derta cases, i.e. the length of hospital stay was reduced by 69.6%.
Studies in the United Kingdom, South Africa and other places have found that the risk of hospitalization in The Case of Aumechjong is lower
For the above data analysis results, the researchers concluded that in the population tested on their outpatient basis, in the population that may have the expected adverse follow-up results, infection with the Omiljung variant was associated with a 52% reduction in the risk of subsequent hospitalization, a 53% reduction in the risk of symptomatic hospitalization, a 74% reduction in the risk of ICU admission, and a 91% reduction in mortality compared with the Delta strain.
The researchers wrote that the severity of the disease in the Case of Omikeron was significantly reduced, regardless of whether they had previously been infected with SARS-CoV-2 and whether they had been previously vaccinated.
The researchers say the study still has certain limitations. For example, because southern California Kaiser Permanente Medical Group (KPSC) members may have different testing opportunities than the general population, the hospitalization rates of Aumequeron cases and non-Semicon cases in this study may not be at the same level as those of the general population. Differences in previous infections and vaccination rates between KPSC members and the general public may also affect the portability of effect size estimated in this study.
Previously, studies in other regions reported similar results – the risk of hospitalization in The Case of Omi kerong was lower.
According to Xinhua News Agency, researchers at the University of Edinburgh and other institutions in the United Kingdom reported on December 22, 2021, the results of a preliminary study on the hospitalization of the Omiljun strain in Scotland, The United Kingdom. The study involved 23,840 cases of Infection in Amiqueroon and 126511 cases of Delta infection between 1 November and 19 December last year.
Studies have shown that patients infected with the Amicorejon strain have a lower risk of hospitalization than those infected with delta strains.
According to CNN, South African research institutes such as the National Institute of Infectious Diseases published a paper on MedRxiv on the medical paper preprint website on December 21, 2021, saying that the risk of hospitalization after infection with Omicron is 80% lower than that of Delta, but the risk of hospitalization after infection with two strains is similar. The study covered more than 161,000 confirmed cases of COVID-19 nationwide in South Africa between 1 October and 6 December.
Both studies were not peer-reviewed and had certain limitations. For example, the University of Edinburgh study involved cases in which infection was confirmed at the primary care level, excluding patients diagnosed by NHS laboratory testing, while the majority of those hospitalized after COVID-19 were in the latter group.
Vaccinations and masks are still important
The researchers of the above-mentioned American study wrote that while our analysis could not infer the absolute effectiveness of the vaccine against different variants, our findings suggest that the vaccine is less protective of the Omiljunn strain than the Delta strain. This result is consistent with studies showing a reduced neutralization efficiency of two and three doses of the BNT162b2 vaccine (Pfizer/BioNTech's mRNA vaccine) against the Semicon strain (relative to the non-Semicon strain).
Similarly, in a number of cases, two doses of vaccination were slightly less effective in preventing hospitalization of infection with Aomi Kerong compared to infection with delta variants.
According to Xinhua News Agency, the European Drug Administration said in a statement released on January 11, 2022 local time, that some recently published research results show that the new crown vaccine is less effective at preventing symptomatic infection caused by the Omiljun strain than other strains, and this effectiveness has gradually weakened over time. As a result, more people who have already been vaccinated against COVID-19 may become infected with the Olmikron strain.
But these findings also suggest that the COVID-19 vaccine remains effective in preventing severe illness and hospitalization from infection with the Omiljun strain. The latest evidence, including real-world effectiveness data, also suggests that people who receive the vaccine booster are better protected.
In the above-mentioned US study, there is also evidence that there was a decrease in both the vaccinated Delta cases and the severe outcome of the Omiljung case, indicating that continued vaccination has important public health benefits.
The researchers said that while the weakening of the case in Omiquerong is an encouraging finding, the stronger transmission capacity of Omilon and the immune escape of previous infections and vaccines remains worrying. The rapid spread of the Omikejung variant, both in our study population and globally, has led to an unprecedented surge in cases. Even if Omilon infection is less severe than other strains, high infection rates in the community can overwhelm the health care system and potentially translate into higher absolute numbers of hospitalizations and deaths.
Therefore, the simultaneous implementation of epidemic prevention strategies, including vaccination, mask wearing and appropriate infection mitigation strategies, remains important for curbing transmission, reducing morbidity and mortality, and reducing the burden on the national health system.
Column Editor-in-Chief: Qin Hong Text Editor: Song Yanlin Title Image Source: Xinhua News Agency Photo Editor: Cao Liyuan
Source: Author: The Paper