Thai nasal-spray Covid vaccines set for tests on humans
The National Science and Technology Development Agency (NSTDA) A Covid-19 nasal spray vaccine developed by the National Centre for Genetic Engineering and Biotechnology (Biotech) has been found to be effective in preventing the disease in mice.
Laboratory mice treated with the adenovirus spray vaccine showed a strong immune response against Covid-19, said Biotech.
Data obtained from the trial will now be used to develop a prototype Covid-19 vaccine to use in a trial on human volunteers.
Dr Anan Jongkaewwattana, director of the agency’s Veterinary Health Innovation and Management Research Group Unit, said the NSTDA research team has made good progress in developing a vaccine prototype.
The team has produced two Covid-19 vaccine prototypes delivered by nasal spray – the adenovirus vaccine and a modified influenza vaccine.
Covid-infected mice given the adenovirus vaccine via nasal spray maintained their weight and did not get sick. A control group given the same vaccine via intramuscular injection also stayed healthy but lost weight.
Meanwhile, the modified influenza vaccine generated high levels of both antibodies and T cell immunity in mice.
Once the animal trials are completed, the team will seek approval from the Food and Drug Administration (FDA) to begin human trials in collaboration with Chulabhorn Royal Academy to test the efficacy of the vaccines against the Delta strain. Phase 1 human trials are scheduled to begin at the end of 2021 and Phase 2 in March 2022. If they are successful, the vaccines should go into production around the middle of 2022.
Dr Anan said the nasal spray is administered via a special syringe directly to the immune system in the mucous membranes of the upper respiratory tract, where most of the viral load is located. Tests have shown that antibodies in the upper respiratory mucosa produce immunity faster and better than intramuscular vaccines.
