Nature: Another Chinese mRNA COVID-19 vaccine on the way

Nature: Another Chinese mRNA COVID-19 vaccine on the way.  Nature Sub-Journal: Yan Jinghua/Gao Fu and others develop mRNA vaccines, one dose can provide long-lasting protection.

As of February 1, 2021, a total of 11 COVID-19 vaccines have been approved or conditionally approved in the world. These 11 vaccines come from: China (4), the United States (1), Germany (1), Russia (2) Models), India (2 models), the United Kingdom (1 models). In addition, 79 vaccines are undergoing clinical trials (23 vaccines in Phase 1, 36 vaccines in Phase 2, and 20 vaccines in Phase 3) [1].

Among the 11 approved vaccines, 2 are mRNA vaccines, 4 are inactivated virus vaccines, 4 are non-replicating virus vector vaccines, and 1 are protein subunit vaccines.

As there is still no effective treatment for the COVID-19 pneumonia, vaccination is the most effective measure to prevent and stop the COVID-19 pandemic.

The mRNA vaccine has the advantages of safety, effectiveness, fast production speed, low cost, and rapid change to deal with virus mutation. So far, there have been two new mRNA vaccines on the market, namely mRNA-1273 from Moderna in the United States and BNT162b1 from BioNTech in Germany and ARCoV, an mRNA new coronavirus vaccine from China Abbio, are in clinical trials.

These three mRNA vaccines that have been on the market or entered the clinic all use a two-dose injection vaccination scheme. In July 2020, a study published by the top immunology journal Immunity showed that a single dose of glycoside-modified mRNA vaccine is sufficient to trigger a strong cellular and humoral immune response to the new coronavirus [2].

So, can a single dose of mRNA vaccination provide sufficient protection?

On February 3, 2021, Yan Jinghua and Gao Fu from the Institute of Microbiology of the Chinese Academy of Sciences, and Tan Wenjie from the Chinese Center for Disease Control and Prevention published the title: A single-dose mRNA vaccine provides a long-term protection for hACE2 transgenic in the journal Nature Communications. Research paper on mice from SARS-CoV-2 [3].

The research team developed a nucleoside-modified mRNA vaccine coated with lipid nanoparticles (LNP), which encodes the RBD domain (mRNA-RBD) of the new coronavirus S protein.

Experimental results show that a single dose of this mRNA vaccine can cause powerful neutralizing antibodies and cellular immune responses, and provide almost complete protection for hACE2 transgenic mice against wild new coronavirus infections. Further studies have shown that the high levels of neutralizing antibodies induced by the mRNA vaccine are maintained for at least 6.5 months.

These data show that this mRNA vaccine only needs a single dose to provide long-term protection against the new coronavirus for hACE2 transgenic mice.

Schematic diagram of mRNA vaccine design

mRNA vaccination provides effective protection for hACE2 transgenic mice

In general, the nucleoside-modified mRNA vaccine delivered by the research team developed by the research team requires only a single dose of vaccination, which is enough to induce powerful neutralizing antibodies and cellular immune responses. Rats provide almost complete long-term protection against wild new coronavirus infections.

Reference materials:
1. https://covid19.trackvaccines.org/vaccines/
2. https://www.cell.com/immunity/fulltext/S1074-7613(20)30326-5
3. https://www.nature.com/articles/s41467-021-21037-2

(source:internet, reference only)

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