Several inhalable COVID-19 vaccines move to human trials

Journal new research Science Advances Introducing the latest research demonstrating the potential efficacy of the inhalable COVID-19 vaccine. The vaccine is one of several vaccines under development designed to be administered with nasal drops.

“While currently available vaccines against COVID-19 have been very successful, most of the world’s population has not yet been vaccinated, and there are vaccines that are easy to use and effective in preventing disease and infection. More is needed, “explains Paul McCray. Researchers at the University of Iowa are working on an inhalable COVID-19 vaccine.

McCray is working with a colleague at the University of Georgia on a single-dose COVID-19 vaccine delivered via nasal drops. Their particular vaccine utilizes a virus called parainfluenza virus 5 (PIV5) that is optimized to express the peaplomer from SARS-CoV-2.

PIV5 is harmless to humans, and previous experiments with the virus as a vaccine delivery system were effective in animal studies against another coronavirus, MERS. New data show that the COVID-19 vaccine is effective in mice and ferrets.

“We have been developing this vaccine platform for over 20 years and have begun developing a new vaccine formulation to combat COVID-19 early in the pandemic,” said university co-leader Biao He. Of Georgia. “Our preclinical data show that this vaccine not only prevents infection, but also significantly reduces the chance of infection.”

Traditional vaccines are usually given by intramuscular injection. However, injections come with many hurdles, and extensive vaccination campaigns are complex and expensive. Injected vaccines often require refrigeration and must be administered by a medical professional.Syringes are also a finite resource, due to supply problems Key issues with the COVID-19 vaccine roll out.

Currently, one nasal vaccine is on the market. A vaccine called FluMist targets influenza and has been approved for about 10 years, but its effectiveness varies from year to year. For several years, both the American Academy of Pediatrics and the Centers for Disease Control and Prevention have recommended injectable influenza vaccines over this inhalable version. But recently changed that advice After the new formulation shows improved efficacy during the 2019-20 flu season.

In addition to the ease of administration of the nasal vaccine, there is a strong hypothesis that direct delivery of the vaccine to the mucosal tissue of the upper respiratory tract may improve local protection from infection. Darrell Irvine, a MIT bioengineer, has been working on the development of inhalable vaccines for several years.

“In some cases, vaccination of muscle may induce immunity on the mucosal surface, but there is a general principle that vaccination from the mucosal surface tends to induce stronger defense at that site. ” Irvine says.. “Unfortunately, there is still no good technique for implementing an immune response that specifically protects these mucosal surfaces.”

A Study from Irvine’s MIT team Announced earlier this year, the new method of attaching peptide vaccines to albumin proteins has shown significant results. A mouse study showed that the inhalable vaccine resulted in a 25-fold increase in immune T cells compared to the same intramuscularly injected vaccine.

A small number of inhalable COVID-19 vaccines are currently in early-stage human trials. In early 2021, researchers at the University of Oxford began a phase I human trial of nasal drops of the ChAdOx1 nCoV-19 vaccine (now well known as the AstraZeneca COVID-19 vaccine).

Principal investigator Sandy Douglas says he is initially studying the safety profile of nasal drops in young and healthy volunteers. Inoculation of the COVID-19 vaccine through the upper respiratory tract tissue is expected to increase the protective effect against mild diseases and infections, but Douglas also said that inhalation should increase vaccine intake. I have.

“Various people find the intranasal delivery system more attractive, which can mean higher vaccine intake in these groups.” Douglas says.. “It may also have practical advantages-nasal sprays are successfully used in other vaccines, such as the flu vaccine used in UK schools.”

Overall around 7 intranasal COVID-19 vaccines It is currently in early human trials, but it is still unclear whether this route of administration works effectively with SARS-CoV-2.Recently, pharmaceutical companies Altimmune has stopped working A weak immune response was shown for inhaled vaccine candidates after the Phase 1 human trial.

Richard Kennedy, an immunological researcher at the Mayo Clinic, says it seems becoming increasingly clear that inhalable vaccines do not work against all pathogens. Some research impasses in the last decade have shown that the development of a nasal spray COVID-19 vaccine may not be an easy task, but hopefully next year the research is progressing rapidly. You will get some answers inside.

“There aren’t many approved mucosal vaccines,” Kennedy said recently. Today’s MedPage.. “These vaccines are effective against certain pathogens, but this may or may not be true for SARS-CoV-2.”

New study published in journal Science Advances..

Source: Carver Medical College