On September 20, 2023, a grand launch event was held in Bangkok, Thailand for Weuphoria, a 13-valent pneumococcal polysaccharide conjugate vaccine ("PCV13") developed and manufactured by Walvax Biotechnology Co., Ltd. ("Walvax", together with its subsidiaries, the "Group", stock code: 300142.SZ). Esteemed experts, senior pediatricians and many parents and children attended the ceremony. Three renowned opinion leaders in Thailand explicated from the perspectives regarding the global epidemiological background of pneumococcal diseases, the distribution of pneumococcal serotypes in Thailand and the serotype coverage of PCVs, as well as the existing scientific evidence for Weuphoria, which support the conclusion that serotypes contained in PCV13 are highly matched with the those prevalent in Thailand, with serotype coverage consistent with PCV15 and superior to PCV10. Vaccination with PCV13 has important clinical and public health value in reducing the burden of pneumococcal diseases among Thai children, and Weuphoria will be a trustworthy choice based upon the standpoints of the three key opinion leaders. Thailand is the second overseas country following Morocco to grant market approval for our PCV13 finished product, which will further boost recognition of this vaccine in the international market and facilitate market access in more countries around the world.

(From right to left: Mr. Huang Zhen, Vice-chairman of Walvax; Professor Kulkanya Chokephaibulkit; Emeritus Professor Tawee Chotpitayasunondh; Professor Wanatpreeya Phongsamart; Mr. Veerachai Tarnmaneewongse, Managing Director of Biovalys）

As the opening of the academic lecture session, Emeritus Professor Tawee Chotpitayasunondh delivered a keynote speech themed "Scientific Importance of S.pneumoniae & Epidemiology and Clinical Impact of Invasive Pneumococcal Disease (IPD)". Professor Tawee is Senior Advisor of Queen Sirikit National Institute of Child Health, Ministry of Public Health, Thailand, Executive Board Member of The Pediatric Infectious Disease Society of Thailand, Executive Board Member of National Vaccine Institute, Thailand, and President of Influenza Foundation Thailand.

"PCVs are highly recommended to be included in a country's NIP considering the great burden posed by IPDs both in Thailand and globally"

Starting from the pathogenesis of S.pneumoniae, he summarized its transmission pattern and the scientific nature of infections with S.pneumoniae He pointed out that the age distribution pattern of IPD incidence in Europe and Asia has showed a “U-shaped distribution” over the years, with both infants and the elderly being high-risk groups. However, there are differences in clinical manifestations between infants and the elderly, and infants bear a higher burden of disease. Professor Tawee also mentioned the surveillance data from Thailand between 2005 and 2010, which indicated a higher hospitalization rate for pneumococcal bacteremia in individuals under 5 years old and over 65 years old. In terms of pneumonia, S.pneumoniae is the leading cause of death in children under 5 years of age. The pneumonia surveillance data from Thailand in 2019 showed that the reported cases of pneumonia in the age group of 0-4 years old were approximately 2,500 per 100,000 population, much higher than those reported in other age groups. Professor Tawee further noted that the mortality rate due to vaccine-preventable diseases (VPDs) in children aged 5 and under in Thailand ranged from 5 to 28 cases per 100,000 people as reported in 1 literature published in 2008, with IPD accounting for the highest proportion at 32%. This places a significant disease burden, and in response to this, the Pediatric Infectious Disease Society of Thailand (PIDST) has updated its immunization recommendations for children. Among these recommendations, Weuphoria, as one of the PCVs, is recommended for Thai children.

(Emeritus Professor Tawee Chotpitayasunondh delivering the speech)

Associate Professor Wanatpreeya Phongsamart, Head of Division of Pediatric Infectious Diseases, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, and Executive Board Member of The Pediatric Infectious Disease Society of Thailand, shared a presentation titled "Serotype Distribution and Serotype Coverage by PCV in Thailand".

"Prevalence of severe/critical cases caused by circulating pneumococcal serotypes is high in Thailand, which require complex and costly treatment due to antibiotic resistance"

Professor Wanatpreeya, who has practiced in the pediatrics department at Siriraj Hospital for many years, has collected and summarized numerous clinical cases as well as epidemiological findings regarding S.pneumoniae and IPDs. She shared a retrospective analysis of 413 cases of IPD or non-bacteremic pneumococcal pneumonia (NBPP) in children aged 15 and under, diagnosed by imaging, from 9 Thai hospitals between 2010 and 2019 showed that 133 cases (32.2%) required ICU treatment, and 11 out of 406 cases (2.7%) resulted in fatalities. Among IPD cases, 32.9% occurred in children aged 2-4 years, 27% in infants aged less than 1 year, and 28.7% of NBPP cases occurred in infants aged 0-11 months. The study collected 51 isolates for pneumococcal serotyping, and 41 (80%) of them were PCV13 serotypes, although only 5.1% of children had received PCV vaccination. Professor Wanatpreeya highlighted several cases of childhood pneumonia, including 1 case of acute necrotizing pneumonia in a child which resulted in severe sepsis/septic shock, multiorgan failure, hemolytic uremic syndrome (HUS) and 1 case of an infant with pneumococcal sepsis both caused by serotype 3 S.pneumoniae, as well as another case involving a hospitalized girl with acute necrotizing pneumonia caused by serotype 19A S.pneumoniae, which was further found to be resistant to clindamycin, erythromycin, and amoxicillin, all requiring synthetical therapy and sophisticated treatments. These case reports emphasize the significant importance of childhood PCV vaccination in preventing severe and fatal cases.

"The most invasive and antibiotic-resistant serotypes are basically covered by PCV13"

Professor Wanatpreeya has compiled data from both international and Thai literatures, indicating that the most invasive serotypes of S.pneumoniae are 18C, 33F, 7F, 19A, 3, and 22F, while 6C, 23A, 35F, 11A, 35B, 19F, 15A, and 15BC serotypes have relatively lower invasiveness. Among them, serotype 19A, when compared to non-19A serotypes, shows lower sensitivity to antibiotics such as penicillin, meropenem, erythromycin, and trimethoprim-sulfamethoxazole (TMP-SMZ). Consequently, since the existing PCV10 does not cover serotypes 3, 6A, 19A, or 4, 18C, the coverage for antibiotic-resistant serotypes is only 28.2% to 57.0%. However, PCV13, which includes all the mentioned serotypes, substantially increases the coverage to 64.9% to 80.0%. Serotype 19A is the most common serotype associated with pneumococcal-related hemolytic uremic syndrome (HUS), followed by serotypes 1, 3, 6A, and 7F. Findings from studies above further underscore the importance of preventing serotypes 3, 6A, and 19A, highlighting the clinical and medical value of PCV13. 

"PCV13 incurs the same serotype coverage as PCV15 does, which is way higher than that incurred by PCV10"

Regarding local serotype distribution and PCV serotype coverage in Thailand, Professor Wanatpreeya shared that multiple epidemiological studies published during 2002 to 2004 on locally prevalent pneumococcal serotypes in Thailand have shown that the predominant serotypes colonizing in children are 6B, 14, 19F and 23F. Among penicillin-resistant pneumococcal serotypes, 19A, 23A, and 6A are the most commonly seen ones. The coverage rates of PCV10 and PCV13 for antibiotic-resistant serotypes among children under 5 years of age were 76% and 92%, respectively. Based on data from studies conducted between 2013 to 2016, the most prevalent serotypes among children aged 0-5 years are 6B, 23F, 19A and 14, and the overall estimated serotype coverage of PCV13/PCV15 for such age group was 93.5%, significantly higher than that of PCV10 (70%-84.4%). Additionally, in one recent study conducted by Professor Wanatpreeya ‘s team in Thailand, among children under 5 years of age in central Bangkok between 2017 and May 2023, the main serotypes causing IPD were 19A (20.3%), 14 (17.4%), 23F (14.5%), 6B (10.1%), and serotype 3 (4.3%). PCV10 serotypes accounted for 41.8%-58.2%, while PCV13 and PCV15 were both at 62.6%.

Professor Wanatpreeya concluded that the most common serotypes causing IPD in children and adults in Thailand are 19A, 6B, 14, and 23F, with serotype 3 becoming more prevalent in adults and showing an increasing trend in children under 5 years of age. Serotypes 22F and 33F are less common across all age groups. Among the major prevalent serotypes, 18C, 33F, 7F, 19A, 3, and 22F exhibit the highest invasiveness, with serotype 19A having a higher resistance rate. Based on the epidemiological background in Thailand and comprehensive findings from literature, the serotype coverage for PCVs is as follows: the serotype coverage of PCV10 ranges from 40% to 85%, and that of PCV13 serotype prevalence ranges from 64% to 93%, which is comparable to PCV15. PCV vaccination is truly an important tool for reducing the disease burden posed by circulating pneumococcal serotypes in Thai children.

(Professor Wanatpreeya Phongsamart delivering the speech)

Professor Kulkanya Chokephaibulkit concluded the academic lecture session with the most updated clinical information for Weuphoria. She serves as Chairperson of The Pediatric Infectious Disease Society of Thailand, Professor at Division of Pediatric Infectious Diseases, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, MD Consultant and Founding Director, Siriraj Clinical Research Center (SCIRES), Board Certified by the American Academy of Pediatrics and Pediatric Infectious Diseases, Executive Board Member of National Vaccine Institute, Thailand, Vice President of The AIDS Society of Thailand.

"The safety, protective effect and trustworthiness of Weuphoria have been fully demonstrated by solid data from clinical trials and post-marketing surveillance"

Building upon the disease burden and epidemiological data presented by Professor Tawee and Professor Wanatpreeya, Professor Kulkanya primarily focused on evidence-based insights to the attending guests regarding Weuphoria. This included existing data and scientific evidence such as clinical designs of Phase I/II and Phase II/III clinical trials, safety and immunogenicity data obtained from such clinical trials, as well as the post-marketing safety surveillance data of Weuphoria since its first licensure in 2020. Professor Kulkanya highly recognizes exceptional performance of Weuphoria in concluded clinical trials and post-marketing mass vaccination, and endorses that Weuphoria is potently immunogenic against all 13 serotypes contained in the vaccine. Long-term persistence regarding antibody levels correspond to each serotype following the complete series with Weuphoria is assured with well-performed safety profile yielded in indication populations, making it a worthwhile choice as PCV for children at increased risk. Professor Kulkanya further proposed various insightful topics for post-licensure studies aimed at improving the clinical evidence of Weuphoria, which hold significant guidance for Weuphoria's consolidation in Thailand and its expansion into broader markets worldwide. 
 

(Professor Kulkanya Chokephaibulkit delivering the speech)

About Weuphoria
In the three years since Weuphoria launch on Dec 31, 2019, 15 million doses have been distributed in China, capturing a major market share. Reporting rates of AEFIs collected worldwide during 2020 to 2022 was 0.1485%. Neither vaccination accident nor vaccine quality event was reported. In 2023, Weuphoria was officially included in Morocco's National Immunization Program.

About Walvax

Founded in 2001, Walvax Biotechnology Co., Ltd. (Walvax) is a leading vaccine producer, engaged in research and development, manufacturing and distribution of safe and efficacious quality vaccines. Headquartered in China's southwestern city Kunming in Yunnan Province, Walvax went to IPO in 2010 (300142.SZ) and started business expansion from traditional vaccines to innovative vaccines. With the vision of dedicating to be the pride domestically and the pioneer globally in the vaccine industry, producing efficacious, quality, innovative and affordable products to protect people from the world’s deadliest diseases, Walvaxs purpose is to help everyone live a healthy life. For further information please visit https://en.walvax.com/about-us/our-company and follow us on Twitter at @WalvaxBiotech and LinkedIn.