Hand, Foot and Mouth Disease Vaccine "Available"

Why is the vaccine against the EV71 virus?

Most severe cases are caused by EV71 infection

According to information released by the State Food and Drug Administration, enterovirus 71 is a type of human enterovirus, referred to as EV71, which occurs mostly in infants under 5 years of age, especially infants under 3 years of age, often causing children's hands and feet. Disease, viral angina, severe cases of children may have myocarditis, pulmonary edema, encephalitis, etc. These diseases are collectively referred to as enterovirus EV71 infection. Gao Hengyu, deputy director of the Department of Critical Care Medicine at Beijing Children's Hospital, told the Beijing News that hand, foot and mouth disease is divided into common and severe cases. In severe cases, the vast majority are caused by EV71 infection. Infants infected with this virus may develop symptoms of nervous system infection and cause heart and lung failure. In severe cases, death may result.

However, there is no targeted treatment for hand, foot and mouth disease. Prevention is an effective means to reduce and control EV71 infection. The development and use of vaccine is the first choice to prevent and control the disease.

Is the hand, foot and mouth disease vaccine reliable?

Protection rate up to 97.3%

In the interview, the reporter learned that since the vaccine is a brand-new viral vaccine, there is no data to support and reference in the process of research and development and evaluation. At the same time, due to the basic research on EV71 virus at home and abroad. It is relatively weak, and the pathogenesis, type of immunity, and incubation period of the disease are clinically explored.

According to the information released by the State Food and Drug Administration, the new vaccine passed the clinical trials of tens of thousands of subjects. The results showed that the vaccine was safe and the protection rate for hand, foot and mouth disease caused by EV71 was 97.3%.

Hand, foot and mouth vaccine production process

1 virus ring, but can not cross the body's first line of defense

There are many kinds of germs in our living environment, and we always want to wait for an opportunity to enter the human body. For example, the well-known hand, foot and mouth disease in recent years is caused by more than 20 enteroviruses such as enterovirus 71 (EV71) and Coxsackie virus group A (CoxA16), especially EV71 and CoxA16. see. Fortunately, due to the body's first line of defense (such as skin, mucous membranes, secretions, etc.), many germs can not pass.

2 Entering the human body, may encounter the second line of defense of the human body

Some germs can cross the first line of defense into the human blood circulation. At this time, the body's second line of defense (phagocytic cells, NK cells, antibacterial proteins, inflammatory reactions, and temperature reactions), such as some bacteria can be swallowed by phagocytic cells.

3 invading cells, infecting and breeding

Some bacteria are suitable for the human body after being mutated, and can dock with the cell recognition site in some specific parts. Just like a key can open the corresponding lock, the human immune system mistakenly thinks that this is a component of the human body without attacking. The virus then enters the cell smoothly, then multiplies in the cell, and some can mutate during reproduction.

4 The patient is ill and passed on to others

EV71 most likes to infect children under 5 years of age. Different infectious diseases have different routes of transmission. They can be transmitted through air, sputum, food, blood, etc., and then transmitted to others.

5 Produce antibodies after rehabilitation

Early diagnosis and treatment, the patient will soon recover. And at least for a period of time, there will be no more specific antibodies - specific antibodies have been produced in the body, and the next time the same virus re-emerges, the antibodies can immediately recognize them and prevent them from entering the cells.

6 Transform the virus and make it a vaccine

Using this principle, the scientists isolated and modified the EV71 virus to remove its pathogenicity, but retained the antigenic properties of the virus, and then industrially produced it in a GMP-certified production plant to prepare a vaccine.

7 vaccine transportation, the whole process of cold chain

The vaccine produced can be marketed after it has been issued a certificate of conformity. However, the vaccine generally needs to be transported in a cold chain throughout the whole process to ensure that the whole temperature is 2 ° C - 8 ° C, transported to the disease control system at all levels by airplane or special refrigerated truck, and finally delivered to the community health service center.

8 Vaccination, production of antibodies

The antigenic substance in the vaccine enters the body with this small needle. Since the EV71 vaccine retains the antigenic properties of the original virus, the human immune system will consider this to be a virus, thus launching a self-defense counterattack. In the process of gradually removing the antigen, a large amount of EV71 antibody is also produced in the body. Vaccination is like telling the body to tell the immune system offenders and letting the immune system learn to capture the full set of offenders.

9 virus attack, antibody force

When the real EV71 virus hits, the antibodies in the body will come forward. Before the virus and the cell identify and dock, they will preemptively connect with the virus recognition site, and the immune system will play a role.

10 Fighting against the enemy virus

This way the immune system re-emerges and captures viruses that have been labeled as foreign substances. At this time, the virus has no power to fight back, and it can only be shackled.