Review on the achievements of prevention and control of epidemic encephalitis B in the past 70 years

Infectious diseases were once the main cause of endangering human health and reducing life expectancy. Practice has proved that vaccination is an effective means to prevent, control and eliminate infectious diseases. The editor recently paid attention to a 70-year tour of health development written by experts from the Immunization Planning Center of the Chinese Center for Disease Control and Prevention (author: Wang Huaqing, An Zhijie, Yin Zundong)-"Review of the 70-year Prevention and Control Achievements of the National Immunization Program for Infectious Diseases", which comprehensively, continuously and systematically evaluated the prevention and control effects of immunization programs at different stages in the 70 years since the founding of New China, it also includes summarizing and comparing the incidence, death and decline of epidemic encephalitis B disease at different stages of vaccination, and summarizing the achievements made in controlling epidemic encephalitis B disease at different stages of immunization strategy from 1950 to 2018. The relevant contents of epidemic encephalitis B prevention and control are now shared as follows:

The annual average incidence and the highest incidence of Japanese encephalitis were in the late stage of surprise vaccination from 1966 to 1977, with 110400 cases and 12.96/100000 respectively. 1971 was the year when Japanese encephalitis B was reported most, with 175000 cases. The lowest stage is the expanded immunization program from 2008 to 2018, with an annual average incidence of 1175 cases, a decrease of 95.43 compared with 1950-1965, and 1800 cases were reported in 2018. The annual average incidence and incidence of Japanese encephalitis decreased significantly during the expanded programme on immunization period, with a decrease of more than 95% (see attached table). The annual average number of deaths and the highest mortality rate of Japanese encephalitis were in the late stage of surprise vaccination from 1966 to 1977, with nearly 13000 deaths and a mortality rate of 1.50/100000. The maximum number of deaths was 26000. The lowest stage of the annual average number of deaths and mortality is the expanded immunization program from 2008 to 2018. The annual average number of deaths is only 57, and the mortality rate is close to 0/100000, which is a decrease of more than 98.50 compared with 1950-1965. The number of deaths in 2018 was 135. The annual average number of deaths and mortality rates decreased most significantly during the expanded programme on immunization (see table). The average annual case fatality rate fluctuated between 4.86 and 18.27 per cent, with the highest stage being the late stage of surprise vaccination in 1950-1965, at 18.27 per cent, and the lowest stage being the expanded immunization programme in 2008-2018, at 4.86 per cent, with a downward trend in case fatality rate (see table).

The highest annual average incidence, morbidity, mortality and mortality of Japanese encephalitis were in the late stage of surprise vaccination, 110400 cases, 12.96 cases/100000, 12800 cases and 1.50 cases/100000, respectively. The highest mortality was in the early stage of surprise vaccination, 18.27%. The development and application of Japanese encephalitis vaccine in China was earlier, and the inactivated mouse brain vaccine was popularized in the early 1950 s. Although the effect was affirmed, it was stopped in 1958 due to serious side effects. Although inactivated vaccines cultured from chicken embryos were developed and applied during the period, they were replaced by inactivated vaccines cultured from hamster kidney cells after 1968 due to unstable effects. In the 1980 s, China developed a live attenuated SA14-14-2 vaccine with independent intellectual property rights. Before the Japanese encephalitis vaccine was incorporated into the national immunization program, it had been widely used in some provinces in accordance with the planned immunization management. In 2007, live attenuated Japanese encephalitis vaccine and inactivated Japanese encephalitis vaccine were included in the implementation plan of the expanded national immunization program. (Note: Vero cell inactivated Japanese encephalitis vaccine was launched in 2004. The above vaccines are all based on the production technology of traditional rotary bottle cell culture. Chengdalibao of Chengda Biology in 2008^®It took the lead in establishing the "bioreactor large-scale cell culture technology" introduced from the United States. Through digestion, absorption and re innovation, it has formed a "bioreactor large-scale vaccine preparation process platform" with independent intellectual property rights, which has overcome the technical problems of large-scale cell culture in China for more than ten years, promoted the great progress of vaccine production technology in China, and become the leader of bioreactor technology. For details, please refer to the "History of Japanese Encephalitis Vaccine Development in China" compiled by the editor).

In the expanded immunization program stage, the incidence, incidence, death, mortality and mortality of encephalitis B have dropped to the lowest level in history, 1200 cases, 0.09/100000, 57 cases, close to 0/100000 and 4.86%, respectively.

Today, when great progress has been made in the prevention and control of Japanese encephalitis in children with vaccines, there are four points worth paying attention to: first, the epidemic of Japanese encephalitis has appeared in the low epidemic areas in the past, and there are new problems of adult outbreaks; second, in the case of increasingly frequent population movements, the immunization strategy of Xinjiang, Tibet, Qinghai and other three provinces and autonomous regions that have not implemented the routine vaccination of Japanese encephalitis vaccine before should make a choice to demonstrate whether to continue to implement the original strategy; thirdly, the current immunization program has been applied for more than 10 years, and the study of immune program optimization should be accelerated from the aspects of immune persistence and dose, and the study of immune program of inactivated vaccine should be carried out in different groups. Fourthly, epidemic of Japanese encephalitis can be predicted, the epidemic characteristics of Japanese encephalitis have changed, and early warning methods should be developed and implemented through population antibody levels, pig infection levels and immunization, combined with precipitation and mosquito species distribution, density, virus carrying and other factors.

Vaccination is the most effective means to control, eliminate and even eliminate infectious diseases. In the 70 years since the founding of New China, vaccination, especially the implementation of immunization programs (EPI), has greatly improved the health level of the people, ensured the fairness of public health measures, achieved social benefits that are difficult to replace by other measures, and achieved a successful model of China's immunization program. China's immunization program has entered a new era. It is our common direction in the future to bring more varieties of vaccines into the national immunization program, let information technology give wings to the immunization program, make vaccination more scientific and standardized, make the immunization program popular to all people who should be species, and give greater play to the value of vaccines.

Chengda Libao^®Does not contain any antibiotics, gelatin, formaldehyde, is a new generation of pure and safe Japanese encephalitis vaccine.

References:

[1] Wang Huaqing, An Zhijie, Yin Zundong. Review on the achievements of National Immunization Program in the prevention and control of seven infectious diseases in the past 70 years [J]. Chinese Vaccines and Immunization, 2019,25(4):359-367