COVID-19 "Sanyang" has come? Will there be a new wave of epidemic peak in November? Expert interpretation | COVID-19 | Sanyang

The COVID-19 seems to be far away from us, but the virus has never disappeared. Recently, "COVID-19 Sanyang people began to appear" on the hot search. At the same time, the infection of COVID-19 variant EG. 5 is on the rise in many places around the world, and the World Health Organization listed it as a "variant that needs attention" last week.

Less than three months have passed since the peak of the "Two Suns", has the "Three Suns" really arrived? Will repeated infections cause greater harm to the body? What impact will the emergence of new strains bring?

Question 1: Has the "Three Suns" arrived?

On August 15th, Ms. Zhao from Beijing woke up feeling pain all over her body, coughing, and sore throat. After testing for the antigen, she understood that she was "positive" again. This is the third time that she has been infected with COVID-19 since December last year and May this year. "The symptoms were milder than the first time, similar to the second time, and the body temperature did not exceed 38 ℃," Ms. Zhao said.

Her experience is not an exception. The latest epidemic weekly report of the 32nd week of 2023 issued by the Beijing Municipal Health Commission shows that the number of reported cases of notifiable infectious diseases in Beijing has increased compared with that of the previous week, and COVID-19 infection ranks first in the number of reported cases. On social media, the topic of "San Yang" has also sparked widespread discussion.

The latest weekly report of the epidemic situation issued by the Beijing Municipal Health Commission shows that COVID-19 infection ranks first in the number of reported cases. Picture Lu Hongzhou, director of the National Clinical Medical Research Center for infectious diseases and president of the Third People's Hospital of Shenzhen, introduced in an interview that in August, about 5 ordinary fever patients in the outpatient department of the hospital were diagnosed with COVID-19 every day, with no obvious increase trend compared with the previous, and mainly "two positive" cases. At present, there are fewer "three positive" cases in Shenzhen, and there is no significant difference in age and other aspects with the "two positive" patient group.

In addition, about 2 COVID-19 patients are hospitalized every day, mainly with basic diseases such as advanced age, diabetes, renal insufficiency, tumor, etc. A few people have not been vaccinated, and there are very few COVID-19 deaths.

Question 2: After a short interval, it became "yang" again?

Some netizens believe that the interval between "three yang" and "two yang" is becoming shorter, and even "three yang" is less than a month after "two yang". Is this possible?

Professor and virology expert at the University of Hong Kong, Jin Dongyan, told reporters that the probability of repeated infections in the short term is very low. Even if infected again, in many cases, the symptoms are lighter rather than heavier.

In his view, it is difficult to define whether it is truly "two yang" or "three yang". At present, nucleic acid testing is no longer conducted in most places, and antigen testing may have interference items. With the cancellation of social distance measures, most people have taken off their masks. If they are infected with other respiratory infectious diseases, including influenza, common cold, respiratory syncytial virus, etc., it is difficult to distinguish the symptoms from COVID-19 infection.

In addition, some people with particularly weak immunity, especially the elderly, generally have a longer duration of positivity, which can reach more than ten days or two to three weeks. Even individuals who have recovered may test positive for nucleic acid within a relatively long period of time.

Lu Hongzhou believes that there is no unified judgment standard for the "three positive" statement at present. Generally, the interval between "two positive" and "three positive" is more than three months, and it needs to be combined with the individual condition of the patient. If there is a recurrence of obvious symptoms of respiratory tract infection related to COVID-19, it is considered to be "three positive".

He said that once COVID-19 is infected, the virus can last for a period of time in the body. Even within three months after the symptoms disappear, it may also be positive through nucleic acid testing. The amount and symptoms of viruses in the human body fluctuate, with occasional yin and yang.

"Less than a month after 'two positive', it was found that the nucleic acid of COVID-19 was negative and positive again, which is generally the residual virus of the last time, rather than repeated infection," said Lu Hongzhou.

Question 3: Will repeated infections affect the immune system?

With regard to the question of "whether repeated infection will damage the immune system and make the symptoms worse", Lu Hongzhou said that COVID-19 is extremely infectious. After obtaining the vaccine, the antibody will naturally decline and there is no absolute protective COVID-19 vaccine. Basically, most people will be infected once or three times a year. But for people with normal immunity, the risk of severe pneumonia or organ damage caused by COVID-19 infection is very low, so there is no need to worry about the impact of "two positive" and "three positive" on the immune system.

He also stressed the need to pay attention to the population with low basic immunity, such as cancer patients, diabetes patients, patients with heart, lung, kidney and other organ dysfunction, and the vast majority of hospitalized patients with reinfection and serious pneumonia and other diseases come from this group.

Jin Dongyan also believes that it is completely unnecessary for ordinary people with normal immune functions to worry too much about the "number of yang".

He said that in general, the majority of people with a normal immune system will only have milder symptoms of "three yang". It is less than a year since the first wave of the epidemic, and the immunity generated after previous infections still exists. The immunity provided by natural infections is very effective in preventing infection, severe illness, and death. If vaccinated again, the protective effect will be better.

"Compared to influenza, people may get it many times in their lifetime. The first time they get it, they may get it the heaviest, and it may become lighter or even less noticeable in the future. After a long time, they may get infected again and become more severe. This is the pattern," said Jin Dongyan.

He also pointed out that if the patient's immune system is weakened, it may also cause persistent infections, which is very rare and requires the use of various antiviral drugs and other medical measures to help them fully recover.

On August 9th, the World Health Organization listed EG.5 as a "variant that needs attention.". Photo question 4: Is it necessary to be alert to COVID-19 mutant EG.5?

On the 16th, Foshan, Guangdong Province reported that the EG.5 variant is gradually gaining an advantage among the prevalent strains in Foshan. Previously, the World Health Organization listed the COVID-19 variant, EG. 5, as a "variant that needs attention".

Jin Dongyan stated that there has been no significant increase in severe deaths or hospitalizations due to infection with EG.5. It is still a sub variant of Omicron, similar to XBB and other Omicron variants. Even though it has become a dominant strain, it has not caused more infections globally, especially in terms of severe illness and death. COVID-19 has been changing, sometimes becoming more infectious or pathogenic, but these changes are only floating in a range, so don't be too nervous.

Lu Hongzhou said that although the production of COVID-19 antibodies will naturally attenuate both naturally and passively, as long as the COVID-19 mutation is not completely separated from the branch of Omikjon, the human body will have cross immune memory. The body will react faster and produce antibodies when encountering EG.5 COVID-19.

He suggested that people with low immune function, such as the elderly, diabetes and basic tumor diseases, should receive COVID-19 vaccine regularly every year. Vaccination strategies include nasal spray vaccine and subcutaneous injection vaccine, and multivalent COVID-19 combination vaccine.

Jin Dongyan also said that most cases of re infection occurred six months later, even for the elderly with poor immunity, it mainly occurred three months later. It is suggested that the elderly can receive COVID-19 vaccine three months after recovery. Healthy non key populations do not require frequent vaccination, as natural infections combined with vaccination can have a strong immune barrier.

Question 5: Will there be a new wave of epidemic peaks in November?

According to the official website of CDC, the number of fever clinics and severe cases of COVID-19 in July showed a fluctuating downward trend. It is said that according to the immune cycle, the next wave of COVID-19 epidemic may occur in November.

Lu Hongzhou said that the infection of COVID-19 has no obvious seasonality. Generally, there will be a small peak in five to six months, but the peak will be smaller and smaller in general, which has no impact on the overall epidemic prevention and control of the country.

"COVID-19 has always been infectious, and has not completely disappeared. From the perspective of Hong Kong, the outbreak of the 'tsunami' was about one year earlier than the mainland, and after that, it also experienced several 'peaks', but this' peak' is very small. No matter how Aomi Kejun changes, there will be no peak like 'Shouyang' again, unless a new virus appears." Jin Dongyan said.

He called for strengthening the monitoring of COVID-19 and increasing the transparency of information. In his view, the first wave of the epidemic to hit is the elderly who have not yet been vaccinated and have not passed the test. This group of people is high-risk and susceptible, with a higher risk of severe illness and death, and does not rely on time for transfer. It is recommended to get vaccinated as soon as possible and take antiviral drugs orally in case of infection.

"What needs to be vigilant is the emergence of COVID-19 virus strain with strong virulence and immune escape. We should do a good job in tracking the variation of COVID-19 and keep high vigilance." Lu Hongzhou also stressed that individuals should maintain a healthy attitude and lifestyle, fully improve their basic immunity and control basic diseases at the same time. Pay attention to personal hygiene and maintain a certain social distance in public places with a large number of people.