Covid-19 nasal spray vaccines in development in Thailand

The National Centre for Genetic Engineering and Biotechnology, known as BIOTEC, believes that the solution to Covid-19 vaccination may be right under our noses. Thai virologists at BIOTEC have 2 nasal spray options currently in development for domestic production that may act as a substitute for Covid-19 vaccines in needle form. They believe a nasal spray or inhaler may provide additional benefits as well.

Covid-19 vaccines traditionally stimulate antibodies in the bloodstream after entering the body via intramuscular injection. But Covid-19 is generally spread through respiratory droplets that enter the body orally or nasally. A nasal spray could deliver protection right at the source of transmission, developing antibodies in the nasal passage where Covid-19 typically enters the body.

Antibodies can develop in the mucosal lining in the nasal passage when ingested through the nose. This technique is not new, with nasal vaccine options available since 2003 to fight influenza, though they haven’t been popular. But adapting the technology to deliver effective Covid-19 protection may change that.

One nasal spray BIOTEC is developing with financial backing from the National Vaccine Institute is the Adenovirus vaccine. Promising research in mice showed that doses injected traditionally and nasally both showed effectiveness in fighting Covid-19, with test mice not getting sick or dying, but those injected lost significant weight, whereas those receiving a nasal dose maintained a healthy appetite and weight, suggesting stronger health protection.

The director of Veterinary Health Innovation and Management Research Group said that researchers in the study are now examining the virus load in the lungs of the test mice as a next step, before petitioning for human trials.

A second interesting vaccine in development combines protection against Covid-19 and the influenza virus. Developers use gene splicing to weaken the virus and add the RBD protein that produces Covid-19 fighting antibodies. The spliced results stimulate the body to create 2 different antibodies simultaneously that fight against both influenza and Covid-19.

Trials of this second vaccine also show high antibody levels and strong prevention of viral infection in the lungs. BIOTECH will ask the Food and Drug Administration to approve Phases 1 and 2 for both Covid-19 nasal vaccines, allowing human trials to begin.

SOURCE: Thai PBS World