A patient receives a nasal spray vaccine for the H1N1 virus in Maryland in 2009. AFP PHOTO / Tim Sloan (Photo by TIM SLOAN / AFP)
Thai virologists, at the National Centre for Genetic Engineering and Biotechnology (BIOTEC), have been developing two candidate nasal spray vaccines, or vaccine inhalers, which they hope will provide an option in the prevention of COVID-19 infection, not just prevent severe symptoms.
Dr. Anan Jongkaewwattana, director of Veterinary Health Innovation and Management Research Group told Thai PBS that most COVID-19 vaccines are being administered via intramuscular injections, to stimulate antibodies in the blood stream, but not enough in the nasal passage to prevent the virus invading the body, adding that COVID-19 enters the body through respiratory system.
The first inhaled vaccine developed at BIOTEC was the Adenovirus vaccine, with financial support from the National Vaccine Institute. Two doses of the vaccine were administered to mice injected with COVID-19 and it was discovered that the mice did not die or fall sick and they ate as normal with their weight remaining stable.
The same vaccine was administered, via intramuscular injection, to other mice and the result was that none of the mice died or fell sick, but they lost weight markedly, said Dr. Anan, adding that researchers are in the process of examining virus load in the lungs of the mice.
The second vaccine being developed is to fight the influenza virus, which was weakened through gene splicing and adding the RBD protein, which produces antibodies against COVID-19, resulting in the body generating two types of antibodies against both COVID-19 and influenza.
Trials of this vaccine in mice show high levels of antibodies that prevent viral infection of the lungs.
Dr. Anan said BIOTEC will seek approval from Thailand’s Food and Drug Administration for Phases 1 and 2 of human trials of the two candidate nasal spray vaccines.
Nasal spray vaccines are not new, said Dr. Anan, adding that nasal influenza spray vaccine has been on the market since 2003, but it is not popular.
He explained that the nasal spray vaccine will produce antibodies in the mucosal lining of the nasal passage, where the virus takes root and invades the body.
Dr. Anan insisted that research and development of vaccines in Thailand is not slower than in other countries, citing the global influenza pandemic two years ago. He claimed that Thailand successfully developed the anti-influenza vaccine shortly after the US.