This winter, as influenza (flu) cases are surging, domestic and international pharmaceutical companies are continually developing various formulations of flu vaccines that are more convenient to administer than traditional injection methods. Notable examples include nasal spray and oral medications.
According to the Korea Disease Control and Prevention Agency, the number of flu patients nationwide recently hit its highest level in eight years since 2016, showing unprecedented epidemic levels. Seasonal influenza, which occurs every winter, is a global phenomenon. The World Health Organization (WHO) estimates that up to 500,000 people globally die from influenza each year.
Until now, the flu vaccine was solely an injectable formulation that pierced the skin to deliver antigens through the blood to produce antibodies. However, as resistance to hospital visits and injections has increased, there has been a growing demand for new formulations that offer more convenient flu prevention.
British pharmaceutical company AstraZeneca (AZ) has developed a nasal spray flu vaccine named "FluMist." It was initially approved for medical institutions in 2003, and in October of last year, it was approved by the U.S. Food and Drug Administration (FDA), allowing patients in the U.S. to self-administer it at home starting this year.
FluMist is known to provide approximately 6 to 12 months of preventive effects with just a single spray of 0.2 mL into each nostril. The drug is absorbed through the nasal mucosa, activating immune cells in the nasal passages and upper respiratory tract. Given that the flu virus primarily infects through the nasal mucosa and upper respiratory tract, the nasal spray effectively blocks the entry. Consequently, research has shown that the nasal vaccine may be more effective than the traditional injectable formulation.
Domestic corporations are also developing this nasal spray vaccine.
NA Vaccine Research Institute, a domestic vaccine development corporation, is developing a nasal spray vaccine based on its self-developed immune booster, Nexavant. Recent animal tests confirmed the efficacy of the nasal spray vaccine, which mixes the antigen from the commercially available vaccine with Nexavant, showing the generation of antigen-specific antibodies in the serum, nasal passages, and lung mucosa. The company reports that it can also prevent flu variant viruses. The results of this animal experiment were published in December of last year in the Nature sister journal, "Nature Communications."
Founded in 2018, NA Vaccine Research Institute was established by CEO Kim Dong-ho, who co-founded Genolution, a company specializing in molecular diagnostics. The institute has immune booster and nasal vaccine technology and collaborates with various domestic and international corporations. It is co-developing immuno-oncology drugs with Massachusetts General Hospital (MGH) at Harvard Medical School and partnering with companies like Yilyang Pharmaceutical and Theragen Bio for flu vaccines and cancer drug development.
Daewoong Pharmaceutical has developed a nasal spray flu prevention product, although it is not a vaccine. It received medical device approval from the Ministry of Food and Drug Safety last May and is expected to launch in the first half of this year. The main ingredients are Zantomonas fermented extract, which forms a physical barrier in the nasal cavity, and camostat, which inhibits the replication and spread of the virus. The company states that a single spray provides a physical barrier for eight hours.
Oral (edible) vaccines are also under development. U.S. biotech company Vaxart is developing a flu vaccine in pill form. Last year, in Phase 2 clinical trials, it was shown to elicit a stronger immune response than injectable formulations. Recently, the company has also been conducting additional Phase 2 studies comparing oral COVID-19 vaccines with mRNA vaccines. The company notes that the absence of a need for syringes eliminates pain and that the ingestion does not require assistance, making it suitable for large-scale vaccination campaigns and ease of storage, transport, and distribution, particularly in developing countries with limited medical infrastructure.