Vaccination in the nose: are live vaccines the corona rescue?

A nasal vaccine against corona sounds strange at first. However, the principle is already being used in some areas. For example, the flu vaccination for children and adolescents is administered as a nasal spray due to a higher protective effect in younger people. Research on the corona vaccine as a nasal spray is already underway.

Why nasal vaccination could help especially in the fight against omicron and how the live vaccine works in the nose.

How does the nasal vaccine work?

While the previous corona vaccines are injected into the muscle, live vaccines against  SARS-CoV-2 could  be administered directly into the nose using a nasal spray.

In addition to being easier to use, nasal vaccines have a decisive advantage over classic vaccines: Although those who have been vaccinated to date produce antibodies against SARS-CoV-2, these are formed as internal protection in the blood and organs, but the mucous membranes of the upper respiratory tract are not sufficiently protected . The virus can therefore continue to affect the throat, trachea and lungs. The classic vaccines thus protect against a serious illness and usually reliably fight SARS-CoV-2 in the body, but an infection is still possible in principle. Infected people can also pass the virus on to others, including risk groups and the unvaccinated.

If the live vaccine is administered via the nasal spray, the body immediately builds up a mucous membrane-based defense with the appropriate antibodies. These protect the upper respiratory tract and thus provide a barrier – directly at the entry point of the virus into the body. Nasal vaccinated people can no longer infect other people with SARS-CoV-2. Virologist Christian Drosten therefore also describes the vaccine as a “milestone” in the fight against  Corona .

In Germany, nasal vaccination is currently used particularly to protect against  influenza  (flu), since conventional flu vaccines only have a low protective effect in children and adolescents. According to the Paul Ehrlich Institute, the nasal vaccine is approved for children and adolescents between the ages of two and 17.

What is the difference between live vaccines and inactivated vaccines?

Live vaccines are used particularly against  measlesmumpsrubella  and  chickenpox  . They contain a small number of reproductive pathogens. However, these are weakened in such a way that they are not able to cause a disease.

The  immune system  responds to the live vaccine, defends itself against the weakened pathogens and begins to produce antibodies against the invader.

As a rule, live vaccines are well tolerated, in rare cases they can trigger mild “vaccination diseases”. For example, after a measles vaccination, you may have a mild, non-contagious rash that goes away on its own after a few weeks.

Inactivated vaccines, on the other hand, contain inactivated, i.e. killed, pathogens or their components, which can no longer multiply in the body.

When can we expect a nasal corona vaccine?

Since both the development of the live vaccine itself and the method of nasal vaccination are very complex, they present the researchers with a number of challenges:

  • When developing the live vaccine, the virus must be greatly weakened, and the virus must not mutate in the body.
  • The principle of the nasal vaccine sounds simple, but implementation is more difficult due to the higher immunity of the mucous membranes. While one can be sure that the vaccine will get into the body with an injection into the muscle, barriers in the  nasal mucosa can  partially repel the vaccine. Developing a safe and reliable method therefore takes time.

Experts are working on the complex challenge in Germany and around the world. The manufacturers of AstraZeneca and the Russian vaccine Sputnik V are already examining whether the vector vaccines would be suitable for nasal vaccination. The American vaccine COVI-VAC is also aimed at nasal use using viral proteins.

According to the World Health Organization, several pharmaceutical manufacturers are already researching nasal vaccination. German experts are also dedicated to the development:

  • Booster vaccinations via the nose in mice have already achieved promising results at the University Hospital Erlangen. The animals developed local antibodies. A mouth spray should follow.
  • The University Hospital in Tübingen is developing a nasal vaccine with a vector vaccine in cooperation with the Max Planck Institute. Sendai viruses are to serve as vectors.
  • A nasal vaccine is also being worked on at the German Center for Infection Research at Hannover Medical School.

In addition to nasal vaccines, oral vaccines could also offer a high level of protection against SARS-CoV-2. Researchers at the University of Würzburg are therefore currently investigating the principle of “living” oral vaccination based on a typhoid vaccine. The vaccine should also produce antibodies against the corona virus in combination with certain bacteria.

It is currently unclear when a nasal spray vaccine can be expected. Many studies are still in the early stages.

This makes it all the more important to take advantage of the current vaccination options. A full vaccination and a booster vaccination can help prevent serious illnesses and relieve the burden on the healthcare system.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *