The local new crown epidemic that recently started from Nanjing Airport has opened up the battle between the Chinese and the delta variant of the new crown virus.
Existing studies have shown that China's new crown vaccine can effectively reduce hospitalization, severe illness and mortality
With the deepening of research, a new vaccine delivery method may make the new crown vaccine block the spread of the virus closer to reality
On July 26, "The Lancet-Infectious Diseases" published the first reported clinical trial of nebulized inoculation of the new crown vaccine
Academician of the Academy of Sciences The aerosolized inhaled new crown vaccine is a way of administering the new crown vaccine through the nasal cavity to stimulate the body's mucosal immunity
Can the inhaled new coronavirus vaccine that stimulate the human mucosal immunity become a big killer to block the spread of the new coronavirus? How to improve the protection rate of the new crown vaccine? How far is the ideal new crown vaccine from us?
Professor Zhang Linqi's team at Tsinghua University School of Medicine conducted research on the first chimpanzee adenovirus vector vaccine in China last year
[Dialogue with Zhang Linqi]
[Dialogue with Zhang Linqi] The Paper: What do you think of the current traditional technical route of the new crown vaccine?
The Paper: What do you think of the current traditional technical route of the new crown vaccine? Zhang Linqi: The ideal vaccine should play a key role in preventing viral infections and curbing disease progression
Zhang Linqi: Recently, there have been some reports that the vaccine’s ability to prevent the infection and spread of the new coronavirus has declined, especially for the Delta mutant strains that have a relatively high infection and transmission speed.
The Paper: How to improve the protection efficiency of the new crown vaccine? How far is the ideal new crown vaccine from us?
The Paper: How to improve the protection efficiency of the new crown vaccine? How far is the ideal new crown vaccine from us? Zhang Linqi: The ideal situation is that after one vaccination, it can protect us from worry for life
Zhang Linqi: In this sense, we have been on the road to improve the protective effect of the vaccine, and the new crown vaccine is no exception
However, this does not hinder our research on new vaccine strategies, new immunization pathways, new immunization doses, and immune protection mechanisms and indicators
Of course, the final scientific questions that need to be answered include the following aspects
First, can nasal immunity induce similar or better immune protection than muscle immunity? Second, in terms of dosage and number of immunizations, what are the advantages of nasal immunization? Third, does nasal immunity induce a stronger immune response on mucosal surfaces such as the respiratory tract, digestive tract, and reproductive tract than muscle immunity, thereby improving the protective ability of mucosal surfaces such as the respiratory tract? Fourth, how durable is the immunity induced by nasal immunity? Ideally, the longer the better? Fifth, how is the immunity induced by nasal immunity against mutant strains? Can the replication of the new coronavirus be greatly reduced, thereby reducing the pathogenicity and spread? Sixth, can nasal immunization be cross-used with other immunization pathways to improve the protective ability and endurance of the vaccine? Seventh, are there any potential side effects and so on for nasal immunity?
The objective and comprehensive answers to these key questions can enable us to have a scientific judgment and evaluation of this new strategy
The Paper: Please tell us about the mechanism of nasal administration of the new crown vaccine and the function of mucosal immunity
The Paper: Please tell us about the mechanism of nasal administration of the new crown vaccine and the function of mucosal immunity
Zhang Linqi: Mucosal immunization is also an important way of immunization.
Some of the influenza vaccines now approved are immunized through the nasal cavity, and some poliovirus vaccines are immunized through the mucous membrane of the digestive tract
.
Mucosal immunity induces a protective immune response mainly depends on the presence of a large number of lymphoid tissues in the mucosal epithelial tissues of the respiratory tract, digestive tract, and genital tract.
After vaccination, it can not only induce an immune response in the mucosa, but also further mobilize and strengthen the whole body.
The immune system improves the body’s overall immunity and protection
.
In short, the mucosal immune system is our body's first line of defense, and it is also the first battlefield for unexpected encounters with pathogenic microorganisms and foreign antigens.
It plays a vital role as an outpost in protecting the body
.
This is the fundamental reason why we hope to vigorously play and improve the protective ability of the mucosal system
.
In particular, the new coronavirus replicates actively in the respiratory tract, and it is also the main route of its transmission.
It is particularly important to improve the immunity of the new coronavirus on the surface of the respiratory mucosa
.
The Paper: For the delta mutant, the current vaccine still has room for improvement in reducing the infection and spread of the new coronavirus.
Is there a good way to improve the protection efficiency in the short term and outperform the mutation speed of the virus?
The Paper: For the delta mutant, the current vaccine still has room for improvement in reducing the infection and spread of the new coronavirus.
Is there a good way to improve the protection efficiency in the short term and outperform the mutation speed of the virus? Zhang Linqi: This is a very critical issue
.
Scientists all over the world are exploring how to overcome the challenges posed by mutant strains
.
From the perspective of the degree of antigenic variation, the first delta (delta) variant found in India is in the middle and lower range, not too high, similar to the alpha (alpha) first discovered in the UK
.
The higher variants are the gamma and beta variants that are popular in Brazil and South Africa
.
Especially the gamma variants in South Africa have greatly reduced the protective ability of some vaccines
.
From the perspective of communication ability, Delta is the strongest, and its popularity in the world is also the strongest
.
Recent studies have shown that its pathogenicity has also been improved, which is one of the focuses of our research and attention
.
Zhang Linqi: Delta (delta) and beta (beta) variants, the vaccine strategy that we and the world are developing includes the following aspects
.
First, how to fully improve the immunity of existing vaccines, including immune boost and cross-immunization, so as to improve the protection against mutant strains?
Second, how to optimize immunization pathways and immunometrics to improve the protective capacity of existing vaccines? These include immunization through the mucous membranes of the nasal cavity
.
Third, comprehensively accelerate the development of vaccines against mutant strains, and improve and expand the effectiveness, broad-spectrum and timeliness of vaccines under the premise of ensuring safety
.
Fourth, accelerate the development of universal vaccines in an all-round way, with extensive and powerful protection against mutant strains that have and in the future, and ultimately achieve the ultimate goal of "one-time-for-all"
.
What is more gratifying is that recent studies have shown that existing vaccines have a certain degree of protection against Delta virus, especially in the case of homologous or heterologous vaccine boosters
.
In addition, the research in our laboratory has also shown that the human body can produce an extremely broad-spectrum antibody response.
We have isolated more than a dozen monoclonal antibodies, which can inhibit all the mutant strains discovered so far
.
A candidate vaccine that we developed also demonstrated the ability of super broad-spectrum anti-mutant strains, which has strengthened confidence and pointed the direction for us to finally successfully develop a universal vaccine and broad-spectrum anti-mutant strain antibody drugs
.
The Paper: At present, nasal administration can produce a better immune effect.
What about its side effects? Have you had any serious adverse reactions to the nasal spray flu vaccine before?
The Paper: At present, nasal administration can produce a better immune effect.
What about its side effects? Have you had any serious adverse reactions to the nasal spray flu vaccine before? Zhang Linqi: The evaluation of the side effects of vaccines is the top priority in the development process
.
Judging from the currently published data, the side effects of nasal immunization are not too great, but further evaluation is needed, especially when the number of immunized populations has increased significantly
.
The previous nasal spray influenza virus vaccine was approved under the premise of strict evaluation of adverse reactions
.
Zhang Linqi: The Paper: Is this method of nasal administration only suitable for viral vector vaccines? Can inactivated vaccines and mRNA be inhaled?
The Paper: Is this method of nasal administration only suitable for viral vector vaccines? Can inactivated vaccines and mRNA be inhaled? Zhang Linqi: Only adenovirus, influenza virus or other viral vector vaccines are more feasible for nasal immunization, while inactivated vaccines and mRNA vaccines are less feasible for nasal immunization
.
The main reason is that after vaccination with the viral vector, there is an active infection process in the epidermal cells of the nasal cavity.
This process successfully delivers the genes expressed by the vaccine to the epidermal cells of the nasal cavity, thereby producing the new coronavirus protein, which in turn induces an immune response
.
Compared with adenovirus vector vaccines, inactivated vaccines and mRNA vaccines are mainly passive in the nasal delivery process.
There is no active process for viral vector vaccines to enter cells, so the immune ability will be relatively weak, and the protective ability to induce immunity is also weak.
Not suitable for nasal immunization
.
Zhang Linqi: Focus on the new crown pneumonia epidemic
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