What are the advantages and disadvantages of the 'nasal drop-type new corona vaccine' that is administered by mist through the nose?

While inoculation of the new coronavirus vaccine is being carried out all over the world including Japan, the development of new types of vaccines is steadily progressing in addition to the vaccines currently in use. Among such many vaccines under development, a research team

at the University of Alabama explains the advantages and disadvantages of 'a vaccine that is inhaled through the nose without injection'.

Scent of a vaccine | Science

Making the case for intranasal COVID-19 vaccines


According to the research team, there are about 100 types of new coronavirus vaccines under clinical trials at the time of writing the article, and 7 of them are nasal inhalation type vaccines (nasal drop vaccines). The research team said, 'Given the characteristics of the new coronavirus and the merits of the nasal vaccine, such as' no needle 'and' high ability to deliver antigens to the infected site, 'only seven types of nasal vaccine are clinical. It's amazing that it hasn't been tested, 'he said, emphasizing the benefits of the new nasal coronavirus.

The nasal drop vaccine is not new, and the live attenuated influenza vaccine (LAIV), which is one of the influenza vaccines used since the 1960s, is also a nasal drop vaccine. LAIV is known to induce the production of immunoglobulin A (IgA) , which is responsible for the immune function in the respiratory tract, in the respiratory tract and serum. In contrast, the injection-type influenza vaccine mainly induces the production of immunoglobulin G (IgG) in serum. 'IgA effectively protects against viral attacks in the respiratory tract and nasal cavity, while IgG requires a sufficiently high concentration of IgG in the hair to protect the respiratory tract and nasal cavity. Therefore, nasal drops may be more protective against the virus than intramuscular vaccines. '

Another advantage of the nasal vaccine is that the research team induces the production of memory B cells and memory T cells to quickly produce immune cells such as B cells and T cells in the airways of the vaccine-administered patients. It is explained that there is.

As mentioned above, there are many benefits to nasal vaccines. However, on the other hand, since 'attenuated vaccine' is used as the material for nasal vaccination, there is a demerit that there is a 'risk of virus infection due to vaccination' that does not occur with mRNA vaccine. In addition, according to the research team, nasal vaccines may have a shorter duration of immunity than intramuscular vaccines.

Based on the above advantages and disadvantages, the research team concludes that it is desirable to acquire long-term immunity with an intramuscular injection vaccine while also acquiring local and effective immunity with a nasal drop vaccine. increase.

in Science, Posted by log1o_hf