How long does the hand, foot and mouth disease vaccine last?

Hand, foot and mouth disease is a relatively common disease at present, and it often occurs in different stages of the population. The impact of hand, foot and mouth disease is very large. First, it will cause fever, low fever, and may be accompanied by blisters and small eczema all over the body. Children suffer and parents are also worried. Hand, foot and mouth disease vaccine is a vaccination method currently developed, which can prevent the spread of hand, foot and mouth disease and have a good effect on physical fitness.

introduce

In March 2013, a vaccine was being developed against hand, foot and mouth disease, an infectious disease that primarily affects children under five years old. Enterovirus 71 (EV71) is the main pathogen that causes hand, foot and mouth disease in humans. The hand, foot and mouth disease vaccine under development refers to the inactivated EV71 vaccine. EV71 inactivated vaccine will be suitable for children over six months old.

Research

When the hand, foot and mouth disease broke out in Fuyang, Anhui in 2008, a large number of medical workers from all over the country gathered in Fuyang to participate in the investigation and research of hand, foot and mouth disease. Among them, there are some medical workers from the Institute of Medical Biology, Chinese Academy of Medical Sciences. The institute is located in Kunming and was founded in 1958. It is an institute integrating basic medical science research and the development and production of biological products. It is also a WHO Collaborative Reference Centre for Enteroviruses.

The institute began conducting enterovirus research in the 1970s and 1980s and has accumulated rich experience in this area. Hand, foot and mouth disease is also caused by enterovirus infection. Che Yanchun said: "For a large-scale epidemic infectious disease, when there is no effective drug treatment, vaccination prevention becomes an effective way." Therefore, a race to find a hand, foot and mouth disease vaccine was launched.

Researchers from the institute isolated and cultured the virus strain from the saliva of a child with severe hand, foot and mouth disease in Fuyang, Anhui. The strain at this time is also called a wild strain. In order to use it to produce vaccines, it needs to be adapted and passaged on cells. After completing the above work, the institute obtained a FY-23K-B strain suitable for vaccine production.

Safety

Once a virus strain suitable for vaccine production is obtained, it needs to be cultured so that it can multiply in large quantities within cells. Therefore, it is very important to choose the right cell culture matrix. Che Yanchun explained: "Viruses usually multiply in large numbers by living in cells within the human body, thereby infecting the body and causing various diseases." The Institute of Medical Biology, Chinese Academy of Medical Sciences, uses human diploid cells KMB17 to culture virus strains. Using human cells to cultivate virus strains can effectively avoid contamination by exogenous factors and potential tumorigenicity, ensuring that vaccines are safer to use.

"This is the biggest feature of the hand, foot and mouth disease vaccine we developed," she said. In recent years, the State Food and Drug Administration has also advocated the use of diploid cells derived from the human body as cell culture matrix for vaccine production from a safety perspective.

After nearly two years of arduous research, the Institute of Medical Biology, Chinese Academy of Medical Sciences, obtained the approval certificates for phase 3, phase 4 and phase 5 clinical trials of the vaccine at one time in 2010. The vaccine was an inactivated vaccine.

The clinical trial phases and phases were completed at the end of 2011. How effective are clinical trials? Che Yanchun said that before the start of each phase of clinical trials, they would organize on-site training on vaccines and vaccination knowledge for relevant personnel, conduct on-site observation and follow-up of the trial infants and young children, and conduct a comprehensive analysis of the immunological effects of the vaccine. "Based on the results of the clinical trials in phases 1 and 2, the vaccine has a good immune response induction effect, with only a small number of extremely mild local reactions, which proves that the vaccine has very good immunogenicity and safety."