Can the mRNA vaccine become the line of defense against the new crown variant?

Article source: Medical Rubik's Cube Pro

Author: Li Yuan

In the field of new drug research and development, mRNA is a hot star technology.

Injecting a small fragment of mRNA into the human body can turn the human body into a vaccine production factory, which stimulates the immune response, thereby producing antibodies and memory cells.

However, the current application of mRNA vaccines has also encountered new challenges, the most prominent of which is to deal with the more "virulent" new coronavirus mutant strains

Can the mRNA vaccines that stand out from the new crown epidemic take up this new game?

Dealing with mutant strains

First of all, in terms of the effectiveness of existing vaccines, the marketed mRNA-1273 (moderna) and BNT162b2 (Pfizer/BioNTech) still have a protective effect on the mutant virus

In early May of this year, two real-world research data showed that Pfizer/BioNTech's BNT162b2 is more than 95% effective against serious diseases or deaths caused by Alpha and Beta variants

Source: NEJM

The effectiveness data of Moderna's mRNA-1273 against mutant strains also performed well

Source: Nature Medcine

Secondly, in terms of development, even if a new vaccine really needs to be re-developed, mRNA vaccines have great potential, because a major advantage of mRNA vaccines is that they are fast.

From the current point of view, under the circumstances that the existing vaccines are still capable of protecting the mutant strains, it should not be the first choice of moderna and BioNTech to develop a new vaccine against a single mutant strain

On August 5, moderna announced the data of booster vaccination.

Source: moderna

The FDA also approved the emergency use authorization for the third booster vaccination of mRNA-1273 (moderna) and BNT162b2 (Pfizer/BioNTech) on August 13

The domestic market dispute

We then turn our attention to China.

There is currently no mRNA new crown vaccine on the market in China.

In March 2020, Fosun Pharma signed a cooperation agreement with BioNTech, and obtained the exclusive development and commercialization of BioNTech's mRNA COVID-19 vaccine in Mainland China, Hong Kong, Macao and Taiwan

On July 14, Fosun Pharma disclosed the news that the mRNA new crown vaccine "Fubitai" has passed the expert review, and the administrative approval is stepping up.

On the 21st of the same month, Watson Biologics registered information about the phase III clinical trial of the mRNA vaccine ARCoVaX that will be conducted in China at the China Clinical Trial Center

Compared with other mRNA COVID-19 vaccines that are still in the early clinical stage, ARCoVaX is undoubtedly the biggest competitor of "Fubitai" in China

According to the information disclosed by Abbio, the protection rate of ARCoVaX is equivalent to that of the marketed vaccine, but its biggest advantage is that it does not require cryopreservation.
It can be stored for at least 7 months at 2°C-8°C.
Store at around minus 70°C
.

It is worth mentioning that, in the current situation where mutant strains are "rampant" in the world and domestic epidemics are repeated, mRNA vaccines that want to temporarily emerge or gain a foothold in the domestic market also need to be sufficiently effective against new crown variants such as Delta
.
As a vaccine with a relatively new mechanism, if the protection rate is not as good as that of an inactivated vaccine, the possibility of being selected may be greatly reduced
.

The current foreign data shows that BNT162b2 (Fubitai) has sufficient effectiveness against a variety of new crown variants, and ARCoVaX has not disclosed data on the prevention of variants.
Which of the two vaccines is better still needs to wait for more data
.

Reference materials:

[1] Vaccines highly effective against B.
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617.
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[2] Lopez BJ, Andrews N.
, Gower C.
et al.
Effectiveness of Covid-19 Vaccines against the B.
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617.
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N Engl J Med (2021)

[3] Chemaitelly, H.
, Yassine, HM, Benslimane, FM et al.
mRNA-1273 COVID-19 vaccine effectiveness against the B.
1.
1.
7 and B.
1.
351 variants and severe COVID-19 disease in Qatar.
Nat Med ( 2021)

[4] Coronavirus (COVID-19) Update: FDA Authorizes Additional Vaccine Dose for Certain Immunocompromised Individuals (Source: FDA)

[5] https://investors.
modernatx.
com/static-files/d427592c-dab4-4715-a568-31207d9832ab