SINOVAC's Varicella Vaccine was Approved by China National Medical Products Administration (NMPA) for Use in Adolescents and Adults Aged 13 Years Old and Above

Beijing, China – June 18, 2024 – Sinovac Biotech Ltd. ("SINOVAC" or the "Company") (NASDAQ: SVA), a leading provider of biopharmaceutical products in China, announced that its PROVARIX (Varicella Vaccine (Vero Cell), Live) has been approved by the China National Medical Products Administration (NMPA) for the use in adolescents and adults aged 13 and above on June 14, 2024. The two-dose schedule shall be applied for the basic immunization with 4 to 8 weeks intervals. Previously, PROVARIX was approved for children aged 12 months to 12 years old.

A randomized, double-blind, controlled phase III clinical trial of our varicella vaccine was conducted among volunteers aged 13 and above in Henan Province, China, from September 2021 to August 2022. The results showed that two doses of the SINOVAC’s varicella vaccine provided good immunogenicity and safety with 2-dose schedules with an interval of 4, 6, or 8 weeks. (Refer to Immunogenicity and safety of a live-attenuated varicella vaccine in a healthy population aged 13 years and older: A randomized, double-blind, controlled study)

SINOVAC's live attenuated varicella vaccine is the first and only one in China that has passed pre-qualification (PQ) assessments by the World Health Organization (WHO). It has been registered in multiple overseas countries, and its safety and efficacy have been widely recognized. After being approved to expand the age of application, this vaccine will better assist in varicella prevention and control, enabling more people to use international quality varicella vaccines and benefit from them.

About Varicella

Varicella is an acute, highly contagious disease caused by varicella-zoster virus (VZV). It’s conservatively estimated in the WHO position paper that varicella causes 4.2 million hospitalizations and 4200 deaths worldwide each year due to serious complications, including encephalitis, pneumonia, and bacterial infections[1].

In recent years, the disease burden of varicella in China has risen year over year, with the reported incidence rate increased from 35.50/100 000 in 2016 to 70.14/100 000 in 2019. Adolescents and adults aged 15 years and above now accounted for 27.9%[2].

From the perspective of age of onset, the highest incident age group of varicella in China has gradually shifted towards the group of adolescents and adults. The incidence rate of varicella in the 15-19 and 10-14 age groups has significantly increased, and the incidence rate and proportion of the elderly have increased as well[3]. In addition, the number of public health emergencies related to varicella reported in middle school, high school, and universities is also gradually increasing[4].

Compared to cases in children, the symptoms of varicella in adolescents and adults are usually more severe[5]. The data shows that the probability of hospitalization for varicella and its complications in adolescents and adults is six times higher than in children[6], and the risk of death is 25 times higher than in children[7]. Getting vaccinated against varicella is the most cost-effective measure to prevent it.

From the epidemiological background of our country, while actively carrying out the prevention and control of varicella in children, attention should also be paid to the protection of varicella in adolescents and adults. To reduce the risk of disease, susceptible adolescents and adults without a history of varicella and immunity can receive two doses of varicella vaccine. For those who have only received one dose of varicella vaccine in the past, a second dose of vaccine should be administered as soon as possible.

About SINOVAC Varicella Vaccine

The China National Medical Products Administration (NMPA) approved SINOVAC's live attenuated varicella vaccine for market use on December 18, 2019.

The SINOVAC attenuated live varicella vaccine is a strain of varicella zoster virus attenuated strain (internationally recognized Oka strain) inoculated into SV-1 human diploid cells independently developed by SINOVAC. After cultivation, the virus is harvested using pure physical technology with core patents, and freeze-dried with stabilizers. The harvesting process does not use digestive cell active chemical additives (such as EDTA), and there is no antibiotic added throughout the production process, which is residue-free and safer. The vaccine meets all testing standards of the World Health Organization (WHO) and the Chinese Pharmacopoeia.

SINOVAC attenuated live varicella vaccine is the first attenuated live varicella vaccine in China to include protective efficacy in its product instructions. Its Phase III clinical research results show that the antibody positivity rate in children aged 1-12 after vaccination is 97.1%. The protective effect of the vaccine on confirmed cases of varicell is 87.1%, the protective effect on breakthrough cases of varicella is 89.2%, and the protective effect on moderate to severe cases of varicella is 100%, with good safety.

On March 22, 2022, the SINOVAC attenuated live varicella vaccine received approval from the National Medical Products Administration (NMPA) for a supplementary drug application (Notice No. 2022B01343), adding product packaging for pre-filled syringes containing vaccine diluents. This will help reduce the operational steps used by vaccine recipients, improve vaccination efficiency, and better meet the needs of vaccination programs.

On November 3, 2022, SINOVAC's live attenuated varicella vaccine passed the WHO pre-qualification (PQ), making it the first and only varicella vaccine in China to pass the WHO PQ.

References

[1]Varicella and herpes zoster vaccines: WHO position paper, June 2014. Wkly Epidemiol Rec. 2014;89(25):265-287.

[2]Dong PM, Wang M, Liu YM, Epidemiological characteristics of varicella in China 2016-2019[J], Chinese Journal of Vaccines and Immunization, 2020,26(04):403-406.

[3]Luan G, Yao H, Yin D, et al. Trends and Age-Period-Cohort Effect on Incidence of Varicella Under Age 35 - China, 2005-2021. China CDC Wkly. 2024;6(18):390-395.

[4]Wang M, Zeng X, Zhang YP, etc. Epidemiological characteristics of varicella public health emergency events in China,2007 - 2021, Chinese Journal of Vaccines and Immunization, 2023,29(03):274-279.

[5]Moore, ZS, Seward, JF, Watson, BM, et al. Chickenpox or smallpox: the use of the febrile prodrome as a distinguishing characteristic. CLIN INFECT DIS. 2004; 39 (12): 1810-7.

[6]Arbeter, A.M. Clinical trials of varicella vaccine in healthy adolescents and adults. Infectious disease clinics of North America 1996, 10, 609-615.

[7]Meyer PA, Seward JF, Jumaan AO, et al. Varicella mortality: trends before vaccine licensure in the United States, 1970-1994. J Infect Dis. 2000;182(2):383-390.