The National Health and Family Planning Commission responded that the actual situation is this:
1.BQ. 1 is the sixth subfamily of BA.5 in Omicron, which is caused by the variation and change of virus in the process of epidemic transmission. BQ. 1. 1 is the first sub-branch of bq.1. The pathogenicity of these evolutionary branches is obviously weakened, and the proportion of severe illness and death is obviously lower than that of the mutant strains that were popular in the early stage.
2. In June, 2022, the mutant strain BQ. 1 was found for the first time among infected people in Nigeria. In September, BQ. 1 and its derivatives were popular in Europe and America, and the proportion increased month by month. 1mid-October, BQ. 1 has gradually become popular in Japan, Singapore and other Asian countries and regions.
3. At present, 49 cases of BQ. 1 and its subclasses have been detected in local cases in 9 provinces of China, but they are not widely prevalent, resulting in a small number of cases, and the clinical severity of patients infected with BQ. 1 has not been observed to increase compared with other variants. At present, the most popular strains in China are BA.52 and BF.7, subfamilies of Ba.5. ..
4.BQ. 1 has attracted worldwide attention, but at present, no country has reported the increase of pathogenicity of BQ. 1 and its subfamily, nor the increase of hospitalization rate and mortality rate. A recent animal study in Japan showed that the pathogenicity of BQ. 1. 1 may be the same as or lower than that of BA.5.
5. Most healthy people are asymptomatic and have mild symptoms after being infected with Omicron series mutants. The public should not believe the unconfirmed rumors reported on the Internet that some countries have a branch BQ. 1 with communication advantages.
6. The general public should adhere to personal protection, maintain healthy and civilized living habits, and actively vaccinate.
7. China will continue to strengthen the monitoring of genomic variation of Omicron mutant strains that are prevalent in the world, imported into China and China, and timely assess the spreading ability, immune escape ability and pathogenicity of emerging dominant strains, so as to provide scientific basis for vaccine research and development and continuous optimization of prevention and control policies.
Extended reading:
Is cough and fever asymptomatic? Expert interpretation
The pathogenicity of Omicron is weakening, and most of them are asymptomatic or mild after infection. Is only cough and fever asymptomatic? Can "Yang" be "Yang" after once? Focusing on the hot issues of public concern, experts from the State Council Joint Prevention and Control Mechanism gave professional answers.
1. Q: If COVID-19-positive patients only have cough and fever, will they have no symptoms?
A: If the positive infected person only has cough and fever, and there is no lung infection, it can be classified as a mild case, but it is not asymptomatic. Judging from the current national case data, asymptomatic and mild cases after Omicron infection account for more than 90%.
According to the current definition, an asymptomatic infected person refers to a person who is positive for COVID-19's pathogen and has no related clinical manifestations, such as fever, dry cough, fatigue, sore throat, hypoesthesia, diarrhea and other symptoms and signs that can be self-perceived or clinically recognized, and whose CT images have no COVID-19 image characteristics.
Mild patients may have symptoms of upper respiratory tract infection such as moderate and low fever, dry throat, sore throat, stuffy nose and runny nose, as well as symptoms such as fatigue and olfactory disorder, but there is no pneumonia.
2. Q: Will "Yang" still be "Yang" after one time? How long is it possible to have a secondary infection?
A: After being infected by COVID-19 once, the immunity formed by the human body will play a certain protective role. However, Omicron may rapidly mutate into a new sub-branch, and its immune escape ability is strong, so people after rehabilitation cannot completely avoid secondary infection.
However, foreign statistics show that after being infected with Omicron, the probability of secondary infection is quite low within three to six months. No matter what the symptoms are, most people will not be infected with Omicron again for a long time.
For individuals, the best way during the epidemic period is to implement protective measures, including wearing masks, paying attention to hand hygiene, keeping social distance, and actively vaccinating COVID-19 vaccine, so as to reduce the risk of infection.
3. Q: Will repeated infections aggravate the symptoms?
A: At present, there is no conclusion that repeated infection will lead to more serious clinical results. Judging from the current cases, even if individual patients have a tendency to aggravate symptoms when they are repeatedly infected, this ratio is very low. The pathogenicity of Omicron virus is weakening. Whether it is the first infection or the second infection, the probability of serious illness is very low.
COVID-19 mutant code-named "Cerberus"
Japan's "madness"?
Since the global outbreak of new crown pneumonia, the virus has undergone several rounds of mutation.
Recently, a new mutant strain named BQ 1. 1 was reported in China. This strain is highly contagious and deadly, also known as "Cerberus", and has been "crazy" in Japan.
On February 8, 65438, the Nihon Keizai Shimbun reported that Yoshiyuki Kawaoka, an outstanding professor at the University of Tokyo in Japan, and his colleagues recently published a paper showing that three antiviral drugs approved by Japan can effectively inhibit the growth of BQ. 1. 1 and another Omicron subtype strain XBB.
The article published in the American New England Journal of Medicine is entitled "Therapeutic Effects of Antiviral Drugs on Omicron Subtypes BQ. 1. 1 and XBB". The conclusion is that some antibody drugs, such as imdevimab-casirivimab, tixagevimab-cilgavimab, sotrovimab and bebtelovimab, may be ineffective against BQ. 1. 1 or XBB in clinic, but antiviral drugs, such as remdesivir, molnupiravir and Naimatvir, are effective against BQ.65438+ in vitro. Therefore,
Even if infected with BQ. 1. 1, Japanese patients are not incurable in COVID-19.
Screenshot of the article "Therapeutic Effects of Antiviral Drugs on Omicron Subtype Variants BQ. 1. 1 and XBB". The picture is taken from the website of New England Journal of Medicine.
In the report of the Nihon Keizai Shimbun, it is specifically mentioned that although BQ. 1 and BQ. 1. 1 are spreading in the United States and Europe, there has not been a large-scale outbreak of this strain in Japan-1Genome analysis conducted in Tokyo from October 8 to October 4 shows that.
The population infected with BQ. 1 and BQ. 1. 1 only accounts for 6.6% of the total infected population.
But at the same time, Japanese media are warning that BQ. 1 may become the dominant strain in Japan in the future. "Nihon Keizai Shimbun" quoted the estimate of the National Institute of Infectious Diseases of Japan, saying that during February 5-1 1, the proportion of BQ. 1 infected people in Japan may increase to 36%; Novel coronavirus experts from the Japanese Ministry of Health told Asahi Shimbun that they are carefully monitoring BQ. 1 because it may affect the future popularity of COVID-19 in Japan.
Screenshot of Asahi Shimbun report title
According to the statistics of Oxford University's "Looking at the World through Data" project, since June 1 1, the number of new deaths per million people in Japan has experienced a new wave of increase, which has now exceeded 1.5. Up to 65438+February 1 day, the total number of Japanese people who died of COVID-19 infection has exceeded 50,000.
In Japan, the number of COVID-19 deaths per million people is increasing every day.
however
At present, there is no direct evidence that the increase in the number of deaths in Japan is inevitably related to the emergence of BQ. 1 and BQ. 1 strains. As of February 5th, 65438, statistical data showed that BA.5 was still the dominant strain in Japan, accounting for 87.76% of the total cases, while BQ. 1 strain accounted for about 6. 12%.
Infection rate of COVID-19 mutant in Japan.
In a report published on February 8, 65438, Asahi Shimbun quoted members of the novel coronavirus Expert Group of the Japanese Ministry of Health as saying that,
Although BQ. 1 may be easier to spread, the risk of serious illness of infected patients is basically the same as that of patients infected with BA.5 strain.
To sum up, at present, scientists still have no unified conclusion on the infectivity, immune escape and severity of BQ. 1* or BQ. 1+0 strains. According to the analysis of existing research results, BQ. 1. 1 has obvious immune escape advantage and faster transmission speed compared with other Omicron subtype strains.
Since Japan entered the winter, it has experienced a new wave of epidemics, and the number of new deaths per million people is increasing every day. But at present, there is no evidence that the increase of death toll is directly related to the emergence of BQ. 1 and BQ. 1 strains. At present, there is no large-scale epidemic of BQ. 1. 1 in Japan, and the dominant strain in Japan is still BA.5
University of Tokyo research:
Compared with BA.5, "Cerberus" strain
The pathogenicity is the same or lower.
Animal studies have shown that the ability of Omicron subtype strain BQ. 1. 1 to cause symptoms is equal to or lower than that of the early COVID-19 strain.
According to the Japan Broadcasting Association, the research was published by the G2P- Japan research group led by Professor Kei Sato of the Institute of Medical Sciences of the University of Tokyo. This paper has not been formally peer-reviewed.
The research report points out that when cells are infected by BQ. 1. 1, its ability to destroy surrounding cells is 2.4 times that of BA.5, which is the dominant strain in Japan at present.
However, although the mutants with strong ability to destroy cells in previous studies often have high pathogenicity, the above studies show that the pathogenicity of BQ. 1. 1 may be the same as or lower than that of BA.5
Scientists also compared hamsters infected with BQ. 1. 1 and BA.5, and they found that the weight changes of these animals were roughly the same. The results showed that compared with BA.5, the lung function of hamsters infected with BQ. 1. 1 did not deteriorate as badly.
Sato Kei said that although the research results may not be directly applied to humans, it is good news that the pathogenicity of the latest COVID-19 strain has not increased. However, he added that anti-infection measures should continue to be taken because the virus is still highly contagious.