Table 2 Efficacy and performance of several mRNA-based vaccines in preventing Mpox infection

Epitopes from 9 CTL, 6 B cells, and 5 HTL were combined using appropriate linkers to create MVC (multi-epitope vaccination) and mRNA-based vaccines.

mRNA and multi-epitope-based vaccines (MVC)

In silico (Immunoinformatics methods)

The first and second dosages are given four weeks apart, using the same default simulation settings.

The antigen titer after the injection peaked on day 5, and then rapidly declined upon the production of IgM, IgG, IgM + IgG, DCs, IFN-gamma, and IL (interleukins), indicating that the designed vaccine candidate may be effective at inducing an immune response against Mpox.

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T- and B-cell epitopes connected with epitope-specific linkers and adjuvants. To create a vaccine that is both stable and highly immunogenic, the Kozak sequence, MITD sequence, tPA sequence, Goblin 5’ and 3’ UTRs, and a poly(A) tail were inserted.

mRNA and multi-epitope-based vaccines (MVC)

In silico (Immunoinformatics methods)

-

The best vaccine model was projected to have high structural stability and binding affinity with immune receptors to induce cellular and humoral immunogenic responses against Mpox by molecular dynamics and immunological simulation assessments.

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Two Mpox quadrivalent mRNA vaccines (mRNA-A-LNP and mRNA-B-LNP). The Mpox-specific antigens A29L, A35R, M1R, and B6R inspired the development of these vaccines.

mRNA-A-LNP and mRNA-B-LNP

In vivo (BALB/c mice) and in vitro (HEK293T, Huh-7, RD, Vero and 143TK cells)

intramuscularly on day 0 at 40 µg. Additionally, on day 14, a booster immunization was given.

Mpox quadrivalent mRNA vaccine was safe by an in vivo safety study since neither mRNA-A-LNP nor mRNA-B-LNP caused any major adverse effects. These mRNA-based vaccinations show promise as a preventative measure against not just Mpox but also other orthopoxviruses like smallpox.

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The tandem 2 A peptides that connect the five Mpox viral antigens (A29L, E8L, M1R, A35R, and B6R) were then codon-optimized.

Multivalent mRNA vaccine (Mpoxac-097)

In vivo (C57BL/6mice)

Intramuscular injection of 0.5 µg (low dose) or 5 µg (high dose) mRNA-LNPs (injection volume: 100 µL).

Two doses of 5 µg of A27, B5, and L1 mRNA-LNPs or a 2 µg average mixture of the four antigenic mRNA-LNPs protected mice against weight loss and death after the VACV challenge.The VACV challenge may be avoided after receiving an Mpoxac-097 vaccine since it produces broadly nABs and an Mpox-specific T-cell response. Mpoxac-097 is as effective and as immunogenic as Mix-5. Antigen tandem co-expression is still enticing because of its less complicated manufacturing process.

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A35R-M1R fusions (VGPox1 and VGPox2) and a combination of encapsulated full-length mRNAs for A35R and M1R (VGPox3) were generated as part of a separate investigation expressing Mpox proteins M1R and A35R.

VGPox

In vitro (Vero cells and 293T cells) and in vivo (Balb/c mice)

LNP-mRNA in 100 µl was intramuscularly injected per mouse, and the mice were boosted at 14 days post 1st vaccination.

These data suggest that compared to co-expression of the two separate proteins, the new mRNA vaccines encoding a fusion protein of A35R and M1R elicited stronger anti-virus immunity. For protection against the Mpox virus, mRNA vaccines are as effective as the present whole-virus vaccines, if not more so.

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Multicomponent Mpox vaccine, which expresses various combinations of viral antigens such as M1R, E8L, A29L, A35R, and B6R.

AR-Mpox5 and AR-Mpox4a

In vivo (C57BL/6mice)

Intramuscular administration of 5 µg of each antigen-encoded mRNA was performed, followed by a three-week augmentation with the identical dose.

The mRNA vaccine candidates of Mpox shown efficacy in mitigating weight loss in BALB/c mice after a high dose of VACV infection. Significant antigen-specific CD8 + T cell responses were seen in the AR-Mpox5 and AR-Mpox4b vaccinated groups after administration of the multicomponent mRNA vaccines. The multicomponent mRNA vaccines induced an immunological response in CD4 + T cells that was inclined towards generating Th1 cytokines when exposed to various antigens.

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A group of scholars employs a quartet of distinct vaccinia viral antigens, including A27, L1, A33, and B5, to fabricate a novel vaccine candidate for poxvirus, denoted as mRNA-ALAB-LNP.

mRNA-ALAB-LNP

In vivo (C57BL/6mice)

Intramuscular injection twice at a 2-week interval with a dose of 20ug per injection.

Substantial levels of cross-reactivity were shown by the fact that serum IgG responses to matching Mpox antigens A35, M1, A29, and B6 were as strong as, or even higher than, responses to vaccinia antigens. This suggests that the mRNA-ALAB, which encodes four vaccinia antigens, might be a promising candidate for future vaccine development against infection with Mpox, smallpox, and other orthopoxviruses.

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A multi-valent mRNA vaccine for Mpox that would target both the EV and MV surface proteins and analyze its effectiveness and molecular basis for protection. The immunogenicity of four mRNA vaccines containing various combinations of EV (A35R and B6R), MV (A29L, E8L, H3L, and M1R), or EV and MV surface proteins.

Multi-valent mRNA vaccine (MV and EV mRNA vaccine)

In vivo (C57BL/6mice)

They were immunized intramuscularly with two doses of 7.5 µg of each antigen-encoding mRNA.

The mRNA-based vaccines elicited a CD4 + T cell response skewed towards the Th1 phenotype and specific to the antigen. The efficacy of mRNA vaccines containing different combinations of EV and MV surface antigens in protecting a mouse model against a lethal VACV challenge was investigated. Results indicated that the vaccine formulation comprising EV and MV antigens demonstrated the highest level of protection.

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Homologs to VACV A27, A33, B5, and L1, a panel of mRNA-LNP-based vaccine candidates encoding four highly conserved Mpox surface proteins implicated in viral attachment, entry, and transmission.

A27, B5, and L1 mRNA-LNPs

In vivo (C57BL/6mice)

Administered an intramuscular injection of 0.5 µg (low dose) or 5 µg (high dose) of mRNA- LNPs (injection volume: 100 µL).

Administration of these antigenic mRNA-LNPs either separately (5 g each) or in an average combination at a low dosage (0.5 g each) evoked Mpox-specific IgG ABs and strong VACV-specific nABs when given twice, despite possible variations in immunogenicity among the four antigenic mRNA-LNPs.

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These vaccines were manufactured using two IMVs (A29L and M1R) and two EEVs (A35R and B6R).

mRNA-A-LNP and mRNA-B-LNP

In vivo (BALB/c mice)

Immunized with 40 µg of mRNA-A-LNP or mRNA-B-LNP, respectively, by twice intramuscular administration.

Mice demonstrated the ability to generate Mpox-specific IgG antibodies and robust VACV-specific neutralizing antibodies. In mice, the immune response to Mpox included the induction of memory B-cell immunity alongside killer memory T-cell immunity. The protection of nude mice against the VACV challenge was achieved by the passive transfer of sera obtained from vaccinated mice exposed to mRNA-A-LNP or mRNA-B-LNP.

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