Sunday, January 7, 2024

Chinese Scientists Make Inhalable Dry Powder COVID-19 Vaccine


Chinese Scientists Make Inhalable Dry Powder COVID-19 Vaccine
The vaccine is a single-dose product that can ‘penetrate deeper and wider’ into the respiratory system.


Scientists from China have made an aerosol-based inhalable vaccine against COVID-19, which they claim provides “effective protection” against infection based on animal trials.

The study, published in the Nature journal on Dec. 13, involved researchers testing “an inhalable, single-dose, dry powder aerosol SARS-CoV-2 vaccine” that they developed. The vaccine uses nanoparticles and contains SARS-CoV-2 antigens, or substances that trigger the immune system to generate antibodies against it. Researchers designed the vaccine to target multiple COVID-19 lineages. The particles were one to four micrometers in size, optimized to be deposited in the deep lung region.

The vaccine was found to induce “strong production of IgG and IgA,” two types of antibodies. It also triggered a response from local T cells, a type of white blood cell that helps fight germs. Collectively, this conferred “effective protection” against COVID-19 among mice, hamsters, and nonhuman primates.

The study noted that while several intranasal immunization products are developing, many are largely limited to the nasal passage. In contrast, aerosol-inhaled vaccines, like the one developed by the researchers, “can penetrate deeper and wider (to major and small airways).” This can confer the vaccine’s benefits even to the lower respiratory tract.

The vaccine also showed promise for “readily responding” to future co-circulation of multiple COVID-19 strains and preventing the transmission of the Omicron variant, the dominant variant under circulation in the United States.

The study noted that the current crop of COVID-19 vaccines was delivered via intramuscular injections to alleviate the infection. However, “vaccines delivered intramuscularly do not provide a first line of protection at the respiratory tract owing to deficiencies of secretory IgA and IgG.”

Several intranasal vaccines are being developed or approved to overcome this. But such vaccines “are in liquid form, necessitating cold chain transportation and storage, and generally require two or three inhaled immunizations or the use of a heterologous booster vaccination.”

These limitations “motivated” the researchers to develop “a dry powder vaccine suitable for single-dose inhalation.”

“The inhalable vaccination addresses a known public health issue, in that there is more enthusiasm for this type of administration than for traditional injection, and a single-dose regimen is favorable for substantially increasing the proportion of total completed vaccination recipients,” the study said.

“Furthermore, the dry powder form of the vaccine can provide savings in storage and transportation costs, potentially supporting increased immunization coverage to remote areas,” it stated.

Moreover, the dry powder vaccine uses a microcapsule that is based on a material already approved by the U.S. Food and Drug Administration (FDA), thus boosting the prospects of the vaccine’s “clinical translation.”

“We envision that our inhaled vaccine could serve as a promising multivalent platform for fighting COVID-19 and other respiratory infectious diseases.”

The study received funding from the National Natural Science Foundation of China, Beijing Natural Science Foundation, the CAS Project for Young Scientists in Basic Research, the National Key Research and Development Program of China, the Strategic Priority Research Program of the Chinese Academy of Sciences, CAMS Innovation Fund for Medical Science, and the Major Science and Technology Special Projects of Yunnan Province.

Some “competing interests” were reported. Authors Hengliang Wang and Li Zhu have patent applications related to cholera toxin B subunit (CTB) nanoparticles submitted by the Beijing Institute of Biotechnology. The dry powder vaccine uses CTB with SARS-CoV-2 antigens.

Author Guanghui Ma is an inventor in a patent application related to porous microcapsules submitted by the Institute of Processing and Engineering.

‘Scandal of Epic Proportions’

A Dec. 13 article in Nature, which commented on the study, calls the dry powder vaccine a “unique approach” to dealing with COVID-19. However, it notes that the vaccine’s “safety and immune potency remain to be tested by clinical trials in humans.”

The researchers “have shown that the dry-powder shot remains stable at room temperature for at least one month, but it will be essential to determine how long this stability lasts at room temperature and above, and how degradation of the vaccine affects immune potency.”

“The question remains whether this 1−4-µm (micrometer) dry powder vaccine will be safe and drive an immune response when inhaled by people,” it said while raising concerns about potential “undesired inflammation.”

Regarding the dry powder vaccine’s effectiveness against emerging COVID-19 variants, the article noted that the study demonstrated the feasibility of including the spike antigens of multiple COVID-19 variant viruses into the vaccine. However, the vaccine’s protective efficacy “was not assessed,” it stated.

In addition, “frequently updating the spike antigen in vaccines might not be a viable solution to the emergence of new strains because SARS-CoV-2 evolves rapidly and thereby evades targeting by antibodies.”

The article has stoked controversy due to a statement that “intramuscularly injected vaccines cannot induce immunity in the mucosal tissues of the airways, which is the site of SARS-CoV-2 entry.”

“There’s a scandal of epic proportions brewing here. A new study in Nature now asserts that mRNA ‘vaccines’ were, by their very nature, never able to stop the spread. Impossible in theory and practice. Yet that was the excuse used to force everyone to get injected with this stuff,” legal author Hans Mahncke said in a Dec. 14 X post.
“I reported this years ago. The mechanism by which the spike proteins work does not innoculate the epithelial lining from infection. Thus, it can still be spread by sneezing and coughing. Nature is a little late to the party,” podcast host Kyle Becker said in a Dec. 15 post on X.
“Intramuscular vaccines cannot induce mucosal immunity in airways (the site of SARS2 entry). This is why they did not stop the spread of Covid. Nor do much to prevent Longcovid. So let’s put that fable to rest & focus on blocking infection already,” author Dana Parish said in an X post.

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