Pfizer, Moderna, AstraZeneca, Janssen … All Covid-19 vaccines currently used in France and in the rest of the world are injected intramuscularly, namely into a muscle of the arm. But while the pandemic is far from over, many other products are being investigated to fight the virus and achieve longer and enhanced immunity.
Among them: intranasal vaccines, which are injected as its name suggests directly into the nose, in the form of a spray. Seven products of this type are currently being studied (in the United Kingdom, the United States or even in Hong Kong) and are in their first phase of clinical trials, we learn from the work of researchers recently published in the magazine. Science. And the first results are promising.
Fight and kill the virus as it enters the body
In addition to the fact that such a vaccine does not require injection through a needle, scientists point out that it has several other benefits. Beginning with gaining more effective local immunity in the nose, one of the main access routes through which Covid-19 enters the body.
According to initial results, these vaccines actually cause a strong immune response on the side of syringes and thus cause the production of antibodies and T lymphocytes directly in the nose. The latter could then destroy the virus once it enters the body, “which would reduce viral replication and accelerate recovery and healing,” the researchers note. Science. In some cases, it could even “prevent infection” with Covid-19.
As shown in the diagram above, these generate the production of antibodies and B and T lymphocytes directly in the nasal cavity and in the deeper airways. This does not occur in the case of a vaccine that is injected through the muscle.
Unlike intramuscular vaccines, intranasal vaccines provide two additional layers of protection: the accumulation of antibodies and T and B lymphocytes in the respiratory mucosa, which form a barrier against infection in these areas.
Study of Science
Combining the two types of faxes, the solution?
Disadvantage of intranasal vaccines, however: initial results show that the immunity caused by a vaccination of this type is likely to be shorter than that provided by an intramuscular vaccine. In Science, researchers therefore hypothesize to combine these two types of vaccination to allow a maximal immune response and protection against Covid-19.
The ideal vaccination strategy could be to use an intramuscular vaccine to achieve long-term antibody creation and create a large repertoire of B and T lymphocytes, and combine it with an intranasal “booster” that produces B and T produces lymphocytes in the cell. the channel.
Study of Science
However, we will have to wait a while before seeing such faxes on the market. All products currently being tested are only in the initial phase of clinical trials.
However, this would not be the first time that a nasal vaccine has been widely used to protect against disease. In the UK, a nasal spray is offered every year to immunize children against the flu, according to the National Health Service (NHS), UK Social Security. About ten years ago, intranasal vaccines were also sent in India to fight the H1N1 virus.