How long is the protection period after vaccination in COVID-19？ Can the elderly be vaccinated？ ….. authoritative answer!

The State Council joint prevention and control mechanism held a press conference on 28th, and as of 24: 00 on March 27th, the country reported that it had inoculated more than 100 million doses of Covid-19 vaccine! These questions of common concern have been answered. Let’s look at them together-

About vaccination—

How long is the interval between two doses of vaccine better?

After the first dose of vaccination, the interval between the second dose of vaccination should be greater than or equal to three weeks, and the second dose of vaccination should be completed as soon as possible within eight weeks after the first dose of vaccine.

If the first shot is inoculated and the second shot is not completed according to the specified time, it is not necessary to restart the inoculation when the second shot is replanted, as long as the second shot is completed. Now there are vaccination sites in Covid-19 all over the country. After telling the vaccination sites about the situation, we should get the second dose of vaccine in time.

Can I get a second shot in a different place? What if vaccine manufacturers are different?

It is suggested to use the variety of the same enterprise as far as possible to complete the two doses of vaccination. If it is said that the same variety cannot be supplied in different places, it can be replaced by vaccine products of other production units of the same kind to complete the two doses of vaccination.

Can the elderly be vaccinated?

At present, Beijing, Shanghai and other regions have been vaccinated with Covid-19 vaccine for some elderly people over 60 years old and patients with chronic diseases who are willing to be vaccinated and in good physical condition under the premise of fully evaluating the health status and infection risk of the vaccinated objects. The next step will be to actively and steadily promote the vaccination of people over 60 years old and patients with chronic diseases in combination with the use effect of vaccines in large-scale populations.

Is it necessary to vaccinate newborns?

At present, the immunization strategy in our country is mainly for people aged 18-59 and elderly people aged 60 and over who are in need and healthy. There is no systematic phase III clinical data about people under 18 years old. With the deepening of research, these data will be obtained later. So when should people under the age of 18 be vaccinated? From the perspective of the whole country, it is considered that the vaccination strategy will be continuously improved based on the needs of epidemic prevention and control and clinical data, including the newborn population.

Some people think that the domestic epidemic situation is relatively stable and there is no need for vaccination. What do you think?

The vast majority of people are susceptible. Vaccination is the most effective prevention and control measure. Vaccination needs to form an immune barrier to play its greatest role, so everyone should be vaccinated. The more people are vaccinated, the stronger the immune barrier is, the faster the vaccination is, and the sooner the immune barrier is formed. If everyone has such a mentality not to vaccinate, the immune barrier will not be established. Once an infectious source is introduced, or when an infectious source exists, an illness or epidemic may occur.

About the vaccine effect—

How long is the effective protection period after vaccination?

Covid-19 vaccine is a new vaccine, which has been developed in a relatively short time and used in human body for a shorter time. At present, the antibody level has been monitored for more than six months. However, antibody is not the only protection index, and there are other factors in the process of vaccine’s function, so it is necessary to carry out research on the persistence of vaccine to confirm how long its protection period is.

In March last year, some people, as the "vanguard" of vaccines, had been vaccinated with inactivated vaccine from COVID-19, which is now on the market. These people have been continuously testing the data of their antibody changes. So far, they have obtained the antibody testing data for 9 months. According to the data, the antibody still has a certain level in 9 months, and the monitoring will continue to be strengthened in the future.

Do people who have been vaccinated need to be vaccinated again?

In the clinical process of the overall design, the booster needle was designed to observe the persistence and protection level of antibodies. At present, the preliminary results show that booster needle can effectively improve the titer of neutralizing antibodies, effectively improve the persistence of antibodies, and also effectively improve the anti-mutation ability of vaccines. In the future, phase III clinical research will be carried out overseas to continuously observe the persistence of antibodies and protection. Is it necessary to carry out booster vaccination? When will you call? Still have to answer according to the results of the next three clinical studies.

Does virus variation have an effect on vaccine effectiveness?

Two kinds of inactivated vaccines of Sinopharm Group China Bio, using the serum after the second and third clinical trials at home and abroad, have carried out cross-comprehensive experiments on the strains found in South Africa and Britain, as well as more than 10 strains found in different regions and epidemic areas in China. The results show that neutralizing antibodies produced by the two inactivated vaccines have a good neutralizing effect on these strains. At present, the strains found in Brazil and Zimbabwe are undergoing neutralization experimental monitoring. Small variation of the virus will not affect the antigenicity of the vaccine, that is, the vaccine will be effective without variation of protective antigen, especially the whole virus inactivated vaccine.

This year, Kexing Zhongwei used the Wuhan strain and the newly mutated British strain and South African strain in various countries to detect the neutralizing antibody in the serum immunized with the vaccine in vitro. The test results showed that the Wuhan strain and the British strain could reach 100% seroconversion, and the South African strain could reach 97% seroconversion. Different individuals have different reactions to the detection results of South African strain, and the detection antibody level of South African strain as a whole is 2 times lower than that of Wuhan strain. At the same time, Kexing Zhongwei has started the vaccine research and development of South African strain and Brazil strain, and the vaccine research of South African strain has been carried out, and the introduction of Brazil strain is in the process.