Scientists in Germany say they've developed a nasal vaccine that can block Covid-19 infections in the nose and throat, where the virus first sets foot. The vaccine uses a weakened but live form of the coronavirus, which closely mimics the natural infection process. In hamster studies, two doses of the vaccine were found to be highly effective in preventing illness, achieving "sterilizing immunity" that eliminates the need for subsequent infections.
The nasal vaccine takes a new approach to an old idea: weakening a virus so it's no longer a threat and then giving it to people to allow their immune systems to recognize and fight it off. The technique, called codon pair deoptimization, makes the virus harder to translate into cells, preventing it from causing disease.
Researchers hope that this new approach will lead to more effective vaccines against Covid-19, particularly in boosting mucosal immunity - the immune defenses in tissues lining the upper airways where the virus first enters the body. This is a promising area of research, as scientists believe that vaccines targeting this site could provide long-lasting protection against future variants.
One study author, Emanuel Wyler, compares this approach to stationing firefighters under the smoke alarm: "If they are already on site, they can immediately eliminate the fire, but if they're like 2 miles away, they first need to drive there, and by that time, one-third of the house is already in full flames." This analogy highlights the potential benefits of targeting mucosal immunity.
However, experts caution that more research is needed before this vaccine can be widely used. The World Health Organization's vaccine tracker lists at least four nasal vaccines for Covid-19 currently in late-stage testing in people, although effectiveness data has not been published.
One other nasal vaccine, developed by Codagenix, uses a live but weakened version of the virus and has shown promising results in early studies conducted in South America and Africa. The German team is eagerly awaiting these results to assess their potential.
The development of Covid-19 vaccines has been slow and challenging, with many hurdles to clear before they can be widely available. Groups working on these vaccines are struggling to raise costs and face skepticism from some quarters that the vaccine "race" has already been won.
In reality, however, new variants of the virus could render current vaccines ineffective in a matter of weeks, highlighting the urgent need for continued research into more effective solutions - such as pan-coronavirus vaccines that induce mucosal immunity. As Wyler notes, "It's strongly attenuated, but it's still a real virus" and would have to be used with caution.
The nasal vaccine takes a new approach to an old idea: weakening a virus so it's no longer a threat and then giving it to people to allow their immune systems to recognize and fight it off. The technique, called codon pair deoptimization, makes the virus harder to translate into cells, preventing it from causing disease.
Researchers hope that this new approach will lead to more effective vaccines against Covid-19, particularly in boosting mucosal immunity - the immune defenses in tissues lining the upper airways where the virus first enters the body. This is a promising area of research, as scientists believe that vaccines targeting this site could provide long-lasting protection against future variants.
One study author, Emanuel Wyler, compares this approach to stationing firefighters under the smoke alarm: "If they are already on site, they can immediately eliminate the fire, but if they're like 2 miles away, they first need to drive there, and by that time, one-third of the house is already in full flames." This analogy highlights the potential benefits of targeting mucosal immunity.
However, experts caution that more research is needed before this vaccine can be widely used. The World Health Organization's vaccine tracker lists at least four nasal vaccines for Covid-19 currently in late-stage testing in people, although effectiveness data has not been published.
One other nasal vaccine, developed by Codagenix, uses a live but weakened version of the virus and has shown promising results in early studies conducted in South America and Africa. The German team is eagerly awaiting these results to assess their potential.
The development of Covid-19 vaccines has been slow and challenging, with many hurdles to clear before they can be widely available. Groups working on these vaccines are struggling to raise costs and face skepticism from some quarters that the vaccine "race" has already been won.
In reality, however, new variants of the virus could render current vaccines ineffective in a matter of weeks, highlighting the urgent need for continued research into more effective solutions - such as pan-coronavirus vaccines that induce mucosal immunity. As Wyler notes, "It's strongly attenuated, but it's still a real virus" and would have to be used with caution.