Beijing will conduct a serum antibody survey on the new coronavirus population. What is the use of testing antibodies?

On January 31, Wang Quanyi, deputy director of the Beijing Center for Disease Control and Prevention, introduced that in order to comprehensively assess the infection situation of the new coronavirus and understand the serum antibody levels of the community population, Beijing will soon conduct a serum antibody survey on the population.

The survey is planned to be completed from February to March this year. It adopts a multi-stage stratified random sampling survey method to select about 5,000 community people from 16 districts and economic development zones for questionnaire surveys and serological specimen collection. The content of the questionnaire includes basic information of the survey subjects, nucleic acid and antigen test results, onset and treatment outcomes, vaccination status and other information.

What is the significance of serum antibody testing? What are IgM and IgG in serum antibody testing? NetEase Health has sorted it out for you, come and learn about it!

1. What is serum antibody testing?

Serum antibodies refer to the corresponding specific antibodies produced by the body's immune system after the body is infected by a certain pathogen. Specific antibodies have the ability to recognize and kill a certain pathogen.

Take the COVID-19 as an example. When a person is infected with the novel coronavirus or vaccinated with the COVID-19 vaccine, the immune system is stimulated and serum antibodies appear. The next time the person recognizes the novel coronavirus, the body has a certain resistance. The immune system can quickly identify and kill the virus, prevent the virus from replicating in the body, and block the virus's harm to the human body. However , as time goes by, the antibody level will gradually decrease, and then we may be infected again.

Serological tests for the novel coronavirus usually include two types of antibodies: IgM and IgG. IgM "arrives early and leaves early", which can reflect whether there is a recent infection; IgG "arrives late and lasts long", which can reflect whether there is a previous infection or serve as a reference for evaluating the effectiveness of vaccines.

2. What is the significance of serum antibody testing?

For society, conducting a survey on serum antibody levels among the population can provide a scientific basis for the next adjustment of epidemic prevention and control measures and provide a reference for optimizing resource allocation.

For individuals, serum antibody testing can achieve the following purposes:

① I have not had any erection, and I want to see what is wrong with me:

Every time an infectious disease breaks out, not everyone will be infected, and there will often be a group of people who remain uninfected.

There are also some people who will be latently infected in small amounts multiple times and produce antibodies. Even if these people undergo nucleic acid testing every day, they may not test positive for nucleic acid because the viral load in their bodies is low and does not meet the positive standard.

If you have not tested positive and want to know which of the above you belong to, you can find out through the new coronavirus serum antibody test. If the antibody test is positive, then you may have been latently infected.

② After being vaccinated, I want to see if I have antibodies to protect my body:

Antigens can cause specific immune responses in the human body and stimulate the body to produce antibodies. Vaccines are also a type of antigen.

If you want to know whether you have antibodies to protect you after receiving the vaccine, you can refer to the method of vaccine effectiveness evaluation and conduct serum antibody testing about 14 days, 3 months, and 6 months after vaccination.

Even if the antibody level detected is low, don’t think that the vaccine is useless. Our immune system has the function of awakening, and the effect of the vaccine in preventing severe illness and death cannot be ignored.

③ I am already “healthy” and want to know about my physical condition:

For those who are already "healthy", testing serum antibodies can help understand their physical condition.

If the antibody level is high, congratulations, it is not dangerous for the time being. If the antibody disappears along with the fever and cough symptoms, it is time to get a booster shot 3-6 months later.

Therefore, if you are curious and want to know whether you have produced antibodies, you can go for a test. If you want to contribute to scientific research, you can also actively participate in the population serum antibody survey.

We need to remind everyone that no matter what the purpose of serum antibody testing is, the analysis of the results requires the participation of professionals. It is best to ask a doctor to conduct a comprehensive analysis based on symptoms or vaccination time, infection time, etc.

3. What is the difference between the new coronavirus serum antibody test, nucleic acid test and antigen test?

So, what are the differences between the nucleic acid test, antigen test and serum antibody test that we usually do? Please see the table below:

Many hospitals and social testing institutions now offer coronavirus antibody testing services, with a single price of around 20-30 yuan.

However, it should be noted that whether antibodies are produced and the amount of antibody titer cannot guarantee or indicate that we are absolutely safe. Regardless of the results of the antibody test, everyone still needs to take protective measures.

Reference sources: Beijing News, People's Daily