Developmnent prospect
1. When is it estimated that the application will be available in the mainland?
Answer: The vaccine should be ready for application soon. It takes some time to arrange for transportation, storage facilities and personnel trainings for the vaccine application.
2. Which groups can be given priority for vaccination?
Answer: This vaccine can be used by all people. However, if taking the initial supply and demand into concern, then high-risk groups should be given priority.
3. At present, there are other vaccines approved for use in the mainland. Can you compare the nasal spray vaccine with the other types, the applicable population and efficacy?
Answer: Other approved vaccines are either subunit or protein vaccines, which are injected intramuscularly, and the immune mechanism is similar to the currently available inactivated vaccines. Nasal spray vaccine is the only vaccine developed to improve upper respiratory tract mucosal immunity. It has minimal side effects and is easy to use. It can be used as a primary and booster vaccine. It is suitable for all ages.
4. How can it help the mainland to achieve the goal of universal vaccination and immunization?
Answer: At present, a number of vaccines in the mainland have been put to use since 2021. The vaccination rate has been increasing day by day. As the epidemic enters a new stage, the main focus now is to keep the spread of the virus at a low level. Nasal spray vaccine can help achieve that by improving respiratory mucosal immunity to reduce virus transmission.
5. Has the application for use in Hong Kong started?
Answer: It should be, and I believe that many Hong Kong people also expect this vaccine to be used in Hong Kong.
6. When can it be applied in Hong Kong?
Answer: The sooner the better, but the application needs to go through a certain set of procedures. In fact, Hong Kong has experience in introducing inactivated vaccines.
More about the vaccine
1. What are the characteristics of the vaccine?
Answer: This is a flu-based influenza viral vector vaccine for COVID-19, using highly attenuated influenza viral genome for expressing receptor binding domain (RBD) of SARS-CoV-2 from the deleted NS1 site, while retaining key antigens for influenza vaccine. Another feature of this vaccine is that it combines flu vaccine and COVID vaccine into one for the protection of both.
2. What are the difficulties in the R&D process?
Answer: We did not have enough manpower in the R&D process. It is said that Pfizer had about 500 researchers to develop mRNA vaccines at that time. Our team was way smaller with far less funding. In addition, the epidemic made it difficult to exchange scientific research materials between Hong Kong and the mainland. We are grateful to the HKSAR Government for its support in various ways, so that this collaboration with mainland could finally come to fruition. I would like to specifically commend our colleagues at Xiamen University and Wantai, for their unremitting efforts in the past three years. Funding aside, they have endured enormous work pressure and mental stress. This is a brand-new vaccine and one cannot fully understand its mechanism with principles of ordinary vaccines. Our vaccine is also the first to be authorised for human use from our technology platform. On behalf of the HKU team, I would like to express my deep admiration to the colleagues from Xiamen University and Wantai team!
3. How to use it, do you need to train the vaccinators?
Answer: The vaccine is easy to use, and vaccinators only need a few minutes of training.
4. If it is approved for use in Hong Kong, how effective is it compared with the bivalent vaccine that has just been used? Who can consider receiving this nasal spray vaccine?
Answer: There is currently no data for direct comparison. People who are in the high-risk group and those who cannot use or have reservations about other vaccines can consider nasal spray vaccine as an option.
5. Can you elaborate a little more on the effectiveness of the new vaccine?
Answer: This has been mentioned in Wantai's announcement, the clinical results of the third phase: the protection rate against hospitalization and severe symptoms (100%); an over 80% protective efficacy against Omicron variant in the population previously vaccinated by inactivated vaccine and 55% effective in the unvaccinated population. (Wantai's announcement: https://mp.weixin.qq.com/s/0YWqOii7CFIs32Pbbv3ekA)
6. Will there be further research to improve the efficacy of Omicron variants? How much time is expected?
Answer: The results of the three phases of clinical trials were carried out in countries where Omicron variants are prevalent, and the effective rates seen are already for Omicron variants. Our work on updating vaccine strains has been underway already. A variety of vaccine seeds targeting Omicron have been prepared, and some of them have been sent to production partners in the mainland.
