How to prevent the Delta strain that can infect people in 14 seconds? Is vaccination still useful?

Recently, the epidemic has spread in Jiangsu, Henan, Hunan, Beijing, Shandong and other places, and sporadic confirmed cases have continued to appear. Friends who are paying attention to the development of the epidemic have frequently heard a word during this period - Delta strain.

On July 27, Ding Jie, deputy director of the Nanjing Center for Disease Control and Prevention, reported that the strain of the Nanjing epidemic was the Delta strain of the new coronavirus; on August 1, Zhao Dongyang, deputy director of the Henan Provincial Center for Disease Control and Prevention, said that after virus sequencing and comparative analysis, the Henan epidemic was mainly caused by the Delta strain of the new coronavirus.

How contagious is the Delta strain? Are the COVID-19 vaccines we are currently taking effective against it? And how can we strengthen our personal protection in our daily lives?

The Delta strain was first discovered in India in October 2020. It is the fastest-spreading and most powerful strain of the new coronavirus discovered in the world.

According to relevant research by the UK Department of Public Health, the Delta strain's ability to spread is 100% higher than the original strain; compared to the Alpha strain that was prevalent throughout the world in the second half of last year, its ability to spread is 60% higher!

Specifically, the scary thing about the Delta strain is that:

1. The Delta strain can be transmitted in 14 seconds without any contact. The viral load is 1,260 times that of the strain that was prevalent last year. It is extremely contagious and can be transmitted in 14 seconds even without any contact.

The Guangzhou police, who were responsible for assisting in the epidemiological investigation, once released a surveillance video: In the same restaurant, Huang (a third-generation infected person) and Lu (a fourth-generation infected person) walked into the bathroom one after another, and the virus was transmitted in 14 seconds without any physical contact.

2. The transmission efficiency is much higher than before. The basic reproduction number (R0) of the original coronavirus strain is about 2.5, while the basic reproduction number of the Delta strain is about 5-8. In other words, in the past one person could infect two or three people, but now one person can infect eight people, and the transmission range is wider.

3. Shortened incubation period, faster onset. For those who have been exposed to the original strain, it takes an average of 6 days for the virus to be detected; however, after 4 days of exposure to the Delta strain, the virus can be detected in the infected person's body. The virus incubation period is shortened by about two days compared to the original one, and the onset is faster.

4. Increased toxicity. Academician Zhang Boli said that judging from domestic data, the time it takes for patients to turn negative is getting longer, and more people are developing from mild symptoms to severe ones.

5. The ability to escape immunity. Data released by the Public Health Agency of England show that after a full two-dose vaccination with the Pfizer vaccine, the effectiveness against the Alpha strain is 93.4%, while the protection against the Delta strain is only 87.9%. This means that the Delta strain has a certain ability to "escape immunity" - that is, the ability to produce antibodies and prevent infection after vaccination.

Speaking of this, many friends began to worry: Are the vaccines we are currently injecting still effective?

In response to this issue, 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: Although the Delta strain is the virus that has "run relatively fast" in the world recently, it is still a coronavirus no matter how fast it runs, and the original prevention and control measures and vaccinations are still effective.

Academician Zhong Nanshan introduced that after comparing the relevant situations of vaccinated contacts and unvaccinated close contacts, it was found that the vaccine had a 63% protective effect against virus infection, a 67% protective effect against the occurrence of symptoms, a 77% protective effect against severe pneumonia, and a 100% protection rate against death.

Academician Zhang Boli mentioned that the vaccine is still effective against the mutated Delta virus, and it has a clear effect in preventing severe illness and reducing mortality, so everyone is encouraged to get vaccinated as much as possible.

Tips

As to whether people who have already been vaccinated need to receive booster shots, there is no conclusion yet, and everything should be based on official notifications.

Practice has proved that wearing masks and washing hands frequently are effective epidemic prevention measures, and we should continue to adhere to them. On this basis, we should also pay special attention to the following 5 points.

1. Replace the mask in time. It is recommended to replace the mask every four hours, and once a day is also acceptable. However, the weather is hot recently and people sweat a lot. If the mask gets wet, it should be replaced immediately, otherwise the protective ability will be greatly weakened.

2. Remember to ventilate regularly. Although the weather is hot, you must not ignore ventilation when turning on the air conditioner. It is recommended to open the windows every 4 hours or so to let the air circulate for at least 20 minutes each time to reduce the content of indoor germs and other pollutants.

3 Avoid unnecessary long-distance travel. Public transportation and travel are important ways for the spread of the epidemic. Therefore, it is recommended that everyone try not to leave their province or city in the near future, and avoid traveling or going on business trips to medium- and high-risk areas or popular tourist destinations to reduce the flow of people and reduce the risk of infection.

4 Reduce unnecessary gatherings. Try to avoid gathering in large groups and do not participate in large-scale gatherings. For activities that must be participated in, remember to wear a mask and maintain a safe social distance.

5. Improve your immunity. Immunity is the best "doctor". You should eat well, get enough sleep, and exercise more to enhance your immunity and reduce the risk of infection.

In addition, Academician Zhang Boli also recommended a tea substitute that helps regulate immunity, which you can also try.

[Recipe and method] 2 grams each of Patchouli, Lotus Leaf, Perilla frutescens, and Honeysuckle, brewed with boiling water and drunk as tea. This is the amount for one person per day, which has the effects of clearing heat, removing summer heat, and stimulating appetite, and is suitable for drinking in the recent hot and humid weather.

On August 5, at the 232nd press conference on the prevention and control of the new coronavirus pneumonia in Beijing, Wang Daguang, a member of the office of the community prevention and control group of the Municipal Epidemic Prevention and Control Leading Group and director of the Municipal Party Building Research Institute, introduced that recently, due to the influence of the Delta variant virus, clustered epidemics have occurred in many places in China, and the epidemic risk and prevention and control pressure faced by the capital Beijing continue to increase. In order to further tighten the community (village) prevention and control fence and build a solid barrier for the prevention and control of the capital, according to the relevant requirements of the Central Committee and the Municipal Party Committee, the city has timely optimized and upgraded the relevant policies on community (village) health management for domestic people coming (returning) to Beijing.

1. Anyone coming to (or returning to) Beijing from any city or region where a case has occurred, or anyone coming to (or returning to) Beijing who has learned through various channels that they may be a close contact, secondary close contact, or other risk group, please be sure to report to your community (village), unit, or hotel where you live as soon as possible, and voluntarily accept health management.

2. For those who have come to (or returned to) Beijing from high-risk areas, they will all be subject to 14 days of centralized observation and 7 days of health monitoring. During the centralized observation period, they should strictly abide by the various management regulations of the centralized observation points, cooperate with nucleic acid testing and health monitoring, and avoid cross infection.

3. For those who have come to (or returned to) Beijing from medium-risk areas, they will all be subject to 14 days of home observation and 7 days of health monitoring; those who do not meet the conditions for home observation will be subject to centralized observation. During the home observation period, they should strictly abide by the relevant requirements for home observation, take good family protection, and stay at home. Anyone who violates the regulations and goes out without authorization will be transferred to a centralized observation point for centralized observation. If they cause the spread of the epidemic or create a risk of transmission, they will be held accountable according to law.

4. For all people coming to (or returning to) Beijing from the areas (cities) where cases have occurred, nucleic acid testing will be required and health monitoring will be implemented for 14 days. If necessary, the disease control department will also determine the control time and scope based on the actual risk situation in the relevant areas and dynamically adjust the prevention and control measures. We will update community control measures according to the latest requirements.

5. For those who are identified as secondary close contacts, in addition to being isolated and observed according to regulations, the people who live and work together shall be subject to closed-loop management according to regulations and shall not participate in any gathering activities. Among them, people living in communities (villages) are generally subject to 7-day health monitoring.

6. People coming to (or returning to) Beijing who are undergoing community health monitoring should pay close attention to their own health status and the health status of those they live with. If any suspicious symptoms such as fever, dry cough, fatigue, etc. occur, they should report to their unit and community (village) in a timely manner, and wear a mask to go to the nearest fever clinic for medical treatment.

7. The above-mentioned home observation, centralized observation, and health monitoring period shall be calculated from the date of leaving the risk area or leaving the new coronavirus infected person, close contact and other persons.

8. Further tighten epidemic prevention measures such as scanning QR code registration, appointment limiting, and wearing masks in gathering public places in communities (villages). For closed activity places such as chess and card rooms, mahjong rooms, and entertainment rooms that are not essential for life in communities (villages), they should be "closed as much as possible" and temporarily closed.

Source: Great Doctors Teach You How to Eat, Beijing Evening News