XBB accounts for more than 90%, and the "Eryang" epidemic will continue

Text | Ling Xin

ed. | Wang Xiao

Photo: Pixabay

On May 30, 2023, patients generally waited more than half an hour at the fever clinic of a hospital in Shanghai. Most of them wear masks, and occasionally communicate two sentences to find that many have tested antigens at home and confirmed positive for the new crown, and some have had a fever for several days.

"After mid-May, [COVID] entered a low-level wave epidemic." Wang Liping, a researcher at the Department of Communication and Prevention of the Chinese Center for Disease Control and Prevention, recently said that combined with multi-channel monitoring, the epidemic will continue for a period of time.

The week before, Beijinger Liu Yun and Shanghainese Zhou Xiao were both "yang". Liu Yun is "Eryang", she is not better than "Shouyang", her body temperature jumped to 39 degrees, but the course of the disease is very fast, and she will get better in four or five days.

Zhou Xiao, who is in his 70s, is already on the verge of severe illness. He tested positive for antigen on May 25, and by the 27th, his oxygen saturation had dropped to 92 and his liver function had begun to suffer. At the strong recommendation of his doctor, he was hospitalized for treatment and began taking small molecule antivirals.

The outpatient situation of hospitals in many places shows that after experiencing growth since mid-April, the number of new crown positive patients has generally entered a relatively stable state.

The antibodies acquired after infection last year have weakened

Yu Changping, chief physician of the Department of Respiratory and Critical Care Medicine of Wuhan University People's Hospital, observed that the new crown patients infected in mid-April were still mainly "Shouyang"; Now, there are more "two yangs", "slowly over time, the antibodies in the human body will decrease, and secondary infections will appear more."

Zhong Nanshan, an academician of the Chinese Academy of Engineering, estimates that 85% of people in the country have been infected with the new crown virus. This mainly happens before February 2023,

The strain infected by "Eryang" patients has changed. At the beginning of the year, the main domestic epidemic strain was BA.5. From September 26, 2022 to January 23, 2023, BA.5.2 accounted for more than 70%, and another BA.5-derived subtype, BF.7, accounted for 23.4%. The new wave of infection is caused by the Omicron subtype XBB.

Chen Cao, a researcher at the Institute of Virology of the Chinese Center for Disease Control and Prevention, said that among the virus sequences collected from May 15 to May 21, XBB accounted for 91.9% of local cases and 95.2% of imported cases.

"People who are infected with BA.5 are still more likely to be reinfected with XBB." Zhong Nanshan reminded.

Zhong Nanshan pointed out at a public event on May 15 that people who have been infected with the new crown virus, the antibodies produced in the body can play a protective role within 4-6 months, and if they face the XBB variant, the protection may be weakened. "Since December last year, it actually seems that this time has now arrived."

The above conclusions are based on real-world research in relevant laboratories and the Singapore region. Two studies from Portugal and Singapore also showed that people who were vaccinated and then infected with the new coronavirus developed a slightly longer protection period, 6-8 months. However, the rate of protection against XBB strains is not high, only 20%-40%.

XBB became the dominant circulating strain, consistent with the world and neighboring regions and countries in China. Chen Cao predicted, "With the increasing number of imported variant strains and the continuous decline of antibody levels in the domestic population, the number of recent cases infected with the XBB variant may increase." ”

In this regard, Wang Liping said, "The entire epidemic prevention and control situation in the country is still stable and controllable. "While patient visits have increased since late April, the overall number of infections is much lower than the number of fever clinic visits at the peak of the last wave of the epidemic. The vast majority of patients are still mild.

The Guangzhou Center for Disease Control and Prevention said on May 25 that the local new crown epidemic has recently fallen slightly after a slight increase around May Day.

Hu Yang, deputy chief physician of the Department of Respiratory Medicine of Shanghai Pulmonary Hospital, analyzed on May 29 based on his own outpatient situation, "The number of people who came to see patients positive for the new crown remained at an order of magnitude, and there was no longer much change. ”

One severe illness is more severe than multiple infections

The feeling of front-line clinical doctors in Shanghai, Wuhan, Nanjing and other places is that in this wave of infection, severe patients will be close to the situation where the peak of severe disease of the new crown lags behind the peak of infection at the end of 2022.

Although the Omicron strain is less virulent, it is still a more dangerous infectious disease than influenza.

Severely ill patients do not manifest themselves just after infection, but develop severe disease after a period of time. Hu Yang has received several critically ill patients with new crowns in recent days, "many of them really can't stay up before coming to the hospital, two of them have cerebral infarction complications just after staying at the hospital's fever clinic."

Positive patients who have been transformed into severe cases are mainly elderly and have underlying diseases. Many of the critically ill patients Yu Changping received were 80 or 90 years old.

Such a patient, once infected with the new crown into a severe disease, regardless of "first yang" or "second yang", the condition will be very serious. Yu Changping said that people over 70 years old are very dangerous, no matter how many times they are infected.

At Shaw Hospital Affiliated to Nanjing Medical University, a patient in his 70s has been given both an artificial lung ECMO and a blood purification treatment device CRRT. "It's quite difficult," Jia Ling, deputy director of the Department of Critical Care Medicine, told Finance and Health, fortunately, drugs, pagers, oxygen supply equipment, etc. are well prepared, and patients in need can use them, which is "very promising."

Theoretically, "two yang" will have milder symptoms than the first yang. The reason is that the previous large-scale infection has formed an immune barrier, coupled with the attenuation of the virulence of the variant, for most immunocompetent people, it is a mild symptom, the recovery time after infection is shortened, and only a small number of people need medical intervention.

However, disease control personnel and doctors have emphasized that if more serious symptoms occur, they should go to the hospital in time. Especially for the elderly, a doctor revealed that some of the patients he received had been hospitalized with a low-grade fever for more than ten days, and admission was a serious illness, which is especially vigilant.

In addition, because not every infected person will have a fever, it is also necessary to pay attention to whether there are other symptoms, whether there is a history of close contact, etc. Especially high-risk groups who have been "yang" should not be taken lightly.

"In severe patients, there is no difference between the first and second yang." Yu Changping told Caijing Health, "One severe pneumonia may cause greater damage to the body than several mild diseases. ”

Yu Changping himself has also experienced two infections, the first developing severe pneumonia, which was cured after 40 days of hospitalization; The second time it was just a low-grade fever, and it got better in two or three days. He felt that after the first infection, his physical strength was significantly affected, and the second time he did not.

Yu Changping said that there is no phenomenon that "the more infections there are, the greater the impact on the body", let alone the saying that "eight times of impotence will die", these rumors have no scientific basis. For young adults with no underlying diseases and normal immunity, if it is only mild, "multiple infections with the new crown are similar to multiple infections with influenza."

As for another concern - the new crown, Chinese doctors are also beginning to pay attention.

According to the definition of the World Health Organization, "long new crown" refers to the presence of symptoms for 3 months after new crown infection, lasting at least 2 months, and cannot be explained by other diagnoses. These include fatigue, shortness of breath, chest pain, loss of taste and smell, etc. About 6% of new crown symptomatic infections develop "long new crown".

Yu Changping noticed that the main manifestations of "long new crown" patients are physical decline, lack of energy, fatigue, etc., some severely ill patients damaged organs or leave damage or need a certain time to recover, but most people do not have very obvious organ or tissue damage, "mainly can not develop into severe disease, mild pneumonia can also recover."

Can I buy oral new crown medicine, do I want to take it?

Prevention of severe disease may still be the current theme of the current round of the epidemic.

A critical care doctor told "Finance and Economics Health" that almost all of the people who have developed severe diseases in this round are elderly people, and it is very difficult to treat, "unlike last year, some young people who are seriously ill can be rescued."

For people with low immunity, elderly groups, and other underlying diseases, Zhong Nanshan's tip is that once infected with the new crown virus, timely drug treatment should be given.

Patients infected in this wave of the epidemic do not have to worry about lack of medicine.

As soon as Zhou Xiao was admitted to the district hospital, he used an imported small molecule anti-new coronavirus drug. In community hospitals in first-tier cities such as Shanghai, domestic new crown drugs are also available. If you choose the Internet consultation platform to issue a prescription and purchase, you can receive it as soon as the next day.

It's just that the reproductive toxicity and genotoxicity written on the long instruction manual make some people prohibitive, who to give and how to eat?

In March 2023, the Respiratory Professional Committee of Guangdong Geriatric Health Care Association issued an expert consensus, listing four groups of people who recommend early taking of small molecule anti-new coronavirus drugs: 1. Those with cardiovascular and cerebrovascular diseases (including hypertension), chronic lung diseases, diabetes, chronic liver diseases, chronic kidney diseases, tumors and other underlying diseases; 2. Immune dysfunction (such as AIDS patients, long-term use of glucocorticoids or other immunosuppressive drugs leading to immunodeficiency); 3. Lymphocyte count

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The aforementioned expert consensus reminds that among the three oral new crown drugs listed earlier, Paxlovid cannot be combined with common underlying disease drugs such as statin lipid-lowering drugs and calcium antagonist antihypertensive drugs; The combination of azvudine with hepatitis B tenofovir fumarate and AIDS drug efavirenz may affect its pharmacokinetics; Monoravir has little benefit in patients who have completed 3 doses of vaccination.

As for young adults, there is no shortage of people who want to recover as soon as possible with oral new crown drugs, "not at work leaders suspect, work colleagues suspect." Yu Changping's suggestion is that if there are no high-risk factors themselves, if they do not develop pneumonia, but flu-like symptoms mainly with fever and cough, they can use ordinary drugs to relieve symptoms. If necessary, it should be taken under the guidance of a doctor.

(Liu Yun and Zhou Xiao are pseudonyms in the text)