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Breaking through the "ceiling" of vaccination coverage requires active participation of children and adolescents.

Globally, the third wave of the new coronavirus epidemic that began from June to July this year has gradually weakened recently. Although the domestic epidemic is mainly small-scale epidemics related to imported cases from abroad, it has also brought many restrictions on the travel of most people. It is worth noting that both at home and abroad, the recent COVID-19 epidemic has shown a large number of infections among children and adolescents. For example, in September this year, the epidemic in Fujian was first discovered in schools. During the epidemic, at least 92 children aged 14 and under were infected, and most of them were transmitted in schools, families and work units. 1. This information suggests that children and adolescents may play a key role in the spread of the disease, and this group cannot be ignored in the control of the epidemic.

Compared with adults, children's vaccination needs to be more scientific and cautious. At present, my country is orderly promoting the COVID-19 vaccine from high to low age groups. What is the significance of vaccination for children and adolescents? What is the effectiveness and safety data of this population in clinical research? What are the special precautions for vaccination? In this article, we will answer these questions one by one.

Children and adolescents have not received the COVID-19 vaccine,

Where are the risks?

Many European and American countries have experienced similar difficulties recently. In the context of school-age children and adolescents not fully launched COVID-19 vaccination, with the arrival of the September school season, the incidence and number of new coronavirus infections in this population have increased significantly. For example, the UK's new cases in the 37th and 38th weeks of 2021 are mainly those aged 5 to 9 and 10 to 19 years old, and the infection rate calculated by this population by population ratio has increased significantly 2.

The number of confirmed infections in children in the United States also reached its peak in September, and the proportion of child infections in all populations increased from 2.6% at the beginning of the epidemic to 26.7%.

Some people may say that although unvaccinated children have a risk of infection, their symptoms after infection are not serious. Is it necessary to get vaccinated? The facts do not support this view. Data show that although most children and adolescents have mild symptoms after infection with the new coronavirus, they are not without severe risks. On average, 371 children infected with the new coronavirus every day during the peak of the epidemic in the United States need to be admitted to the hospital for treatment because of the serious condition. 4. Early data released shows that one-third of the children hospitalized for COVID-19 need to be admitted to the intensive care unit (icu), and children with underlying diseases have a higher risk of progressing to severe illness after infection. 5.

More importantly, children play an important role in the transmission of the disease. In families where adults and children live together, even if adults have been vaccinated, it is still possible to bring the virus into the home through contact, infect unvaccinated children, and further cause intra-school and family transmission. A retrospective analysis conducted by CDC in the United States 6 provides inspiration for the important role of school-age children and adolescents in the school-family transmission chain. The study shows that children and adolescents (7 to 19 years old) infected with the new coronavirus (7 to 19 years old) caused intra-school transmission in 18% of families (35/194 families). Among these families with transmission, nearly half (45%) of family members were infected and some family members were hospitalized.

To sum up, vaccination for children and adolescents is of great significance from the perspective of reducing individual infection risks or preventing transmission. In order to better protect children, families and more risky groups, this "shortcoming" among the immunization coverage population needs to be filled.

Are the existing vaccines effective for children?

Is it safe?

When discussing the benefits and risks of children vaccinating the new crown vaccine, scientific evidence must be based on scientific evidence. At present, a variety of new crown vaccines have been evaluated in children and adolescents of different ages. Overall, children and adolescents have no inferior immunogenicity after vaccination with the new crown vaccine or better than adults, with good tolerance, and serious adverse events are rare.

bnt162b2       The mRNA vaccine is the first COVID-19 vaccine to evaluate the effectiveness of preventing infections in a Phase III clinical trial 7. The results of this Phase III clinical trial show that 7 days after receiving two doses of bnt162b2 vaccine, the effectiveness of preventing symptomatic infections is 100% (95%     ci: 75.3~100)7.

Children get COVID-19 vaccination

What should you pay attention to?

Although there is sufficient necessity for children to receive the COVID-19 vaccine, and the existing research data also show the effectiveness and safety of vaccines for this population, parents may still have some concerns when actually vaccinating. The "Expert Consensus on Children's New Coronavirus Vaccination" 12 recently published provides a number of suggestions on precautions and handling of adverse reactions during vaccination, providing support for children to receive the COVID-19 vaccine safely. We summarize some issues that parents may be more concerned about as follows.

1What type of vaccine can be received at present? How many shots are needed?

At present, the vaccine approved for emergency use in children in my country is the inactivated COVID-19 vaccine. The vaccination interval between 2 doses is recommended to be ≥3 weeks. The second dose should be completed within 8 weeks after the first dose is completed. The vaccine approved for use in children abroad is the mRNA vaccine. The vaccination interval between 2 doses is recommended to be ≥3 weeks.

2 Can the new crown vaccine be vaccinated with other vaccines at the same time?

It is not recommended to be vaccinated with other vaccines at the same time. The vaccination interval between other vaccines and the new coronavirus vaccine should be >14 days. When rabies vaccine, tetanus vaccine, rabies or tetanus immunoglobulin is required due to animal injuries, trauma, etc., the vaccination interval between the new coronavirus vaccine may not be considered.

3 Which children are suitable for getting the COVID-19 vaccine?

Currently, all healthy children aged 12 to 17 are suitable for vaccination with the new crown vaccine. my country will further determine the vaccination plan for young children based on relevant evidence-based medical evidence of safety and effectiveness. In the stable period of chronic diseases, children who use small and medium doses of glucocorticoids and most biological agents (except preparations for B cells such as rituximab) can also be vaccinated.

4 Which children should be temporarily suspended or contraindicated for vaccination?

Children with acute or chronic disease activity should consider vaccination after 3 months of stable condition. Patients with immunosuppressive drugs, leukemia chemotherapy, and hematopoietic stem cell transplantation should temporarily postpone vaccination according to the treatment conditions.

Allergic reactions to the relevant components contained in the new coronavirus vaccine, severe allergic reactions in the past, and adverse reactions to those who have been vaccinated with the new coronavirus vaccine (excluding general reactions such as low fever, local swelling and pain) are contraindicated for vaccination with the new coronavirus vaccine.

5 What should be done if adverse reactions occur?

The short-term local reactions (pain, redness, swelling, nodules, etc.) and systemic reactions (fever, chills, myalgia, headache, etc.) that occur after the new coronavirus vaccination are general reactions. Acetaminophen or other antipyretic and analgesic drugs can be used to relieve symptoms. For allergic reactions with mild symptoms, appropriate observation can be given; for vaccinated children with severe allergic reactions, they should refer to the first aid plan in the children's allergic guideline to deal with related allergic conditions.

Special adverse reactions are very rare. Potential serious adverse reactions in vaccination for children and adolescents should be strictly monitored, highly vigilant, and timely discovery and report.

6What should children pay attention to after vaccination?

(1) After children are vaccinated with the new coronavirus vaccine, they must observe at the vaccination site for at least 30 minutes, and do not gather or play during the observation period.

(2) Keep the local skin clean and dry after vaccination, avoid scratching with your hands, avoid excessive pressure and irritation during bathing, and keep local clean after bathing.

(3) After receiving the new coronavirus vaccine, you can exercise and eat normally, avoid strenuous exercise and contact with known allergens. Pay attention to rest and do not stay up late.

(4) Avoid suggestion and induce adverse reactions to children, and closely observe changes in physical condition and body temperature. If the fever continues to subside or serious adverse reactions occur, report to the vaccination site and seek medical treatment in a timely manner.

(5) The clinically used new coronavirus antibody detection is different from the neutralizing antibody titers detected by the virus neutralization test. It is not recommended to use clinical antibody detection to determine the effectiveness of vaccination.

7Do children still need protection after receiving the COVID-19 vaccine?

After children are vaccinated with the new coronavirus vaccine, they should still take good protection and avoid infection. Protective measures include wearing masks, washing hands frequently, personal hygiene, and maintaining social distance, avoiding going to densely populated areas and paying attention to indoor air circulation.

Summarize

The COVID-19 vaccine is the greatest hope to end the current pandemic. my country's COVID-19 vaccination population coverage rate ranks among the top in the world. According to the press conference report of the State Council's Joint Prevention and Control Mechanism, as of September 18, more than 1 billion people in my country have completed the full vaccination process of 13, which means that the vast majority of healthy adults have completed vaccination. Breaking through the "ceiling" of vaccination coverage rate requires active participation from children and adolescents.

Existing research data shows that children can effectively induce immune responses after receiving different COVID-19 vaccines. The phase IIii-efficient data of the mRNA vaccine shows that teenagers aged 12 to 15 can effectively prevent infection after receiving the vaccine. Globally, although the specific vaccination strategies of different countries are different, for example, the United States and Canada approved children over 12 years old as early as May this year to receive the bnt162b2 vaccine, and the recommended interval is ≥3 weeks 14; the United Kingdom and Norway recommend that children aged 12 to 15 get one dose of bnt162b2 vaccine 15, 16, but gradually promoting children and adolescents to receive the new crown vaccine is the general trend. In the future, with the improvement of clinical trial results, the approval of more COVID-19 vaccines and the accumulation of post-market monitoring data, it is believed that children and adolescents will provide more vaccine options, and it is expected to provide this population with more opportunities to meet individual needs.

"This wave of epidemic involves many provinces and regions, with many activity trajectories of confirmed cases, long lines and wide areas. Once prevention and control is not effective, the risk of spillage and spread is extremely high."

On October 15, a train departing from Dunhuang, Gansu passed through more than 30 places in four provinces: Ningxia, Inner Mongolia, Shanxi and Hebei, and arrived in Beijing 36 hours later.

Starting yesterday (19th), Baotou City, Inner Mongolia, Bayannur City, and Rizhao City, Shandong Province, successively issued emergency searches to find close contacts for passengers in 9 cars, Ai Moumou, the second close contact. Ai Moumou was diagnosed as a confirmed case on the 18th. The next day, another person in the same car was diagnosed in Beijing.

It was not just this west-to-east train, from the northern border to the Guanzhong Plain and then to the Yunnan-Guizhou Plateau. In 3 days, the epidemic, which was first discovered in the "Shanghai Tour Group", spread rapidly through a developed transportation network, and has affected at least 37 people in 7 provinces.

According to the National Health Commission, yesterday, 17 new local confirmed cases and 4 asymptomatic infections were reported in mainland China. Today, Lanzhou City, Zhangye City, Ningxia Yinchuan City, Wuzhong City, Xingtai City, Hebei City, and Zunyi City, Guizhou City announced a total of 10 new infections.

The four new confirmed cases in Gansu Province today are close contacts of the confirmed case "Zhang" on the 19th. Zhang went to Jiayuguan, Ejina Banner, Zhangye and other places to travel from the 11th, and returned to Lanzhou on the 15th.

The confirmed case of Yinchuan City, Hou Moumou, had spatial intersections with Ai Moumou, the first confirmed patient in this round of epidemic, who had traveled to Yinchuan in the northwest.

The two new cases in Wuzhong City were close contacts of Xu, a local confirmed patient, on the 19th. The latter had traveled to Shuidonggou, Ningxia, Populus euphratica forest, Ejina Banner, Inner Mongolia and other places.

The confirmed case in Zunyi City, Guizhou yesterday went to Ejina Banner, Inner Mongolia on October 12, and the two new infections today are also close contacts.

"This wave of epidemic involves many provinces and regions, with many activity trajectories of confirmed cases, long lines and wide areas. The Chengguan District of Lanzhou City where the epidemic occurs is very dense, and the prevention and control is very difficult. Once the prevention and control is not effective, the risk of spillage and spread is extremely high." Today, Ren Zhenhe, a senior official from Gansu Province, said when guiding the epidemic prevention and control work in Lanzhou.

At present, the source of this round of epidemic infection is still unclear, but according to the published epidemic investigation information, Ejina Banner, Inner Mongolia is the initial intersection point. The 7 "Shanghai Tour Group" and 5 "Lanzhou Tour Group" that were initially discovered in this round of epidemic have eaten at the local Tongnange Restaurant. As of now, there are 20 infected people related to the restaurant.

Ejina Banner is located at the westernmost end of the Inner Mongolia Autonomous Region, bordering Mongolia, with a border line of 507 kilometers. According to Baidu maps, the Tongnange Restaurant of Ejina Banner is only 87 kilometers away from the Zhongmontzek Port. Lanzhou has announced the epidemiological investigation of infected people, showing that 5 people from the "travel group" visited the Ceke Port on October 13.

Ceke Port is a national annual open port. Since the outbreak of the new crown epidemic, cross-border freight drivers have tested positive for nucleic acid samples. In June this year, because Mongolian drivers tested positive, the port reduced the number of daily clearance vehicles.

On September 24, Mongolia added 2,662 new confirmed cases, setting a record high. By early October, Mongolia had more than 2,000 confirmed cases per day for more than 20 consecutive days. On October 13, a local positive case was found in Erlianhot, Inner Mongolia, a city at the China-Mongolia border port, and was a closed-loop management personnel of the logistics park.

It is reported that Ejina Banner has launched an iv-level emergency response mechanism. It closes the channels and Ceke ports in and out of Ejina Banner, implements 48-hour temporary control, and launches nucleic acid testing for all employees.

The latest news shows that the National Health Commission and the National Disease Control and Prevention have sent working groups to Inner Mongolia, Gansu, Shaanxi and Ningxia to guide the local epidemic response work.
Chapter completed!