Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Nov:109:105392.
doi: 10.1016/j.ebiom.2024.105392. Epub 2024 Oct 18.

Single-chain A35R-M1R-B6R trivalent mRNA vaccines protect mice against both mpox virus and vaccinia virus

Tianxiang Kong  1 , Pei Du  2 , Renyi Ma  2 , Han Wang  3 , Xuehui Ma  4 , Jian Lu  5 , Zhengrong Gao  6 , Hai Qi  7 , Ruiqi Li  8 , Hao Zhang  9 , Fei Xia  9 , Yuanlang Liu  9 , Ruyu Wang  9 , Kai Duan  9 , Zejun Wang  9 , Qihui Wang  10 , George F Gao  11
Affiliations

Single-chain A35R-M1R-B6R trivalent mRNA vaccines protect mice against both mpox virus and vaccinia virus

Tianxiang Kong et al. EBioMedicine. 2024 Nov.

Abstract

Background: Mpox has spread to many countries around the world. While the existing live attenuated mpox vaccines are effective, advances in 21st century technologies now enable the development of vaccines with more specific antigens, clearer mechanisms, and more controllable side effects.

Methods: We systematically evaluated the immunogenicity and protective efficacy of the A35R, M1R and B6R antigens of the mpox virus (MPXV). With these findings, we designed three single-chain trivalent mRNA vaccines (AMAB-wt, AMAB-C140S and AMB-C140S) by integrating the soluble regions of these antigens into single mRNA-encoded polypeptides based on their protein structures. Then, the immunogenicity and protective efficacy of these single-chain mRNA vaccines were evaluated in mice models against both VACV and MPXV.

Findings: The three single-chain vaccines elicited neutralising antibodies that effectively neutralised both VACV and MPXV. The single-chain vaccines or cocktail vaccine containing mRNAs encoding soluble antigen (sA35R + sM1R + sB6R) exhibited 100% or 80% protection against a lethal dose of VACV challenge, while the cocktail of full-length antigens (A35 + M1 + B6) and the live attenuated vaccine, VACV Tian Tan (VACV-VTT), completely failed to protect mice. Moreover, the single-chain vaccines significantly reduced viral load in the lungs and ovaries of MPXV-challenged mice.

Interpretation: Compared with the cocktail vaccines, our single-chain designs demonstrated similar or superior immunogenicity and protective efficacy. Importantly, the simplicity of the single-chain vaccines enhances both the controllability and accessibility of mpox vaccines. We believe these single-chain vaccines qualify as the next-generation mpox vaccines.

Funding: National Natural Science Foundation of China and Youth Innovation Promotion Association of the CAS.

Keywords: Chimeric; Single-chain; Trivalent; mRNA vaccine; mpox.

PubMed Disclaimer

Conflict of interest statement

Declaration of interests G.F.G., Q.W., P.D., T.K., and R.M. are listed as inventors on patent applications for the three trivalent mpox mRNA vaccines. The other authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Evaluation of MPXV antigen combinations with single-gene mRNA vaccines. (a) Mice immunisation, challenge and sample collection schedule (n = 5 per group, 110 in total). (b and c) Titers of IgG specific to the indicated MPXV antigens on day 13 (b) and 27 (c). Numbers on top of each graph indicate the fold-increase relative to the cognate antigens in the LNP group. (d) PRNT50 of neutralising antibody against VACV-WR. Numbers on top indicate geometric mean titer (GMT), data are shown as GMT ± 95% confidence interval (CI). (e) ELISpot assay quantifying the IFNγ-secreting splenocytes after re-stimulation by peptide pools of MPXV antigens. Data are shown as means ± SEM (standard error of the mean). (f and g) Probability of survival (f) and percentages of weight change (g) of mice vaccinated with single-gene mRNA vaccine (s) or LNP. Percentages in the legend indicate the probability of survival 12 days post–challenge. Weight change data are shown as means ± SEM. All ELISA and PRNT assays were repeated twice.
Fig. 2
Fig. 2
Design, in vitro expression and immunogenicity evaluation of trivalent mpox mRNA vaccines with single-chain chimeric immunogen. (a) Mpox mRNA vaccines were designed by integrating A35R, M1R, or B6R. Mice were immunised with the same protocol as Fig. 1a, with VACV-VTT as control (n = 5 per group, 100 in total). (b) In vitro expression of the three mRNAs encoding single-chain chimeric immunogens. Each mRNA was transfected into HEK293T cells. Expression of single-chain chimeric immunogens in the supernatant was analysed by western blot. (c) Titers of IgG specific to the indicated MPXV antigens on day 13 (left) and 27 (right). Numbers on top indicate the fold-increase relative to the cognate antigens in the LNP group. Statistical significances were calculated by the two-way ANOVA with Tukey's multiple comparisons test (∗, p < 0.05; ∗∗, p < 0.01). (d and e) PRNT50 of neutralising antibody against VACV-WR (d) and MPXV (e). Numbers on top indicate geometric mean titer (GMT), data are shown as GMT ± 95% CI. Statistical significances were calculated by the Kruskal–Wallis test with Dunnett's multiple comparisons test (∗, p < 0.05; ∗∗, p < 0.01). (f) ELISpot assay quantifying the IFNγ-secreting splenocytes after re-stimulation by peptide pools of MPXV antigens. Data are shown as means ± SEM. Statistical significances were calculated by the two-way ANOVA with Tukey's multiple comparisons test (∗, p < 0.05; ∗∗, p < 0.01; ∗∗∗, p < 0.001; ∗∗∗∗, p < 0.0001). All ELISA and PRNT assays were repeated twice.
Fig. 3
Fig. 3
Evaluation of protective efficacy of trivalent mpox mRNA vaccines with single-chain chimeric immunogen. (a and b) Probability of survival (a) and percentages of weight change (b) of mice vaccinated with mpox mRNA vaccine challenged with 7 LD50 of VACV-WR. (c) Mice immunisation, challenge, and sample collection schedule (n = 5 per group, 45 in total). (d and e) Probability of survival (d) and percentages of weight change (e) of mice vaccinated with mpox mRNA vaccine or VACV-VTT vaccine challenged with 30 LD50 of VACV-WR. All percentages in the legend indicate the probability of survival 12 days post–challenge. All weight change data are shown as means ± SEM. (f and g) Viral load in the lungs was examined by plaque assay (f) and qPCR assay (g). Data are shown as means ± SEM. Statistical significances were calculated by the ordinary one-way ANOVA with Dunnett's multiple comparisons test (∗, p < 0.05; ∗∗, p < 0.01). Plaque and qPCR assays were repeated twice.
Fig. 4
Fig. 4
Evaluation of the antibody persistency and protective efficacy of trivalent mpox mRNA vaccines against MPXV. (a) Mice immunisation, challenge and sample collection schedule (n = 5 per group, 30 in total). (b) Titers of IgG specific to A35R, B6R and M1R in sera collected 28-, 60-, 98- and 166-days post first dose. Data are shown as GMT ± 95% CI. (c) Percentages of weight change of mice vaccinated with mpox mRNA vaccine challenged with MPXV. All weight change data are shown as means ± SEM. Statistical significances were calculated by the two-way ANOVA with Dunnett's multiple comparisons test (∗, p < 0.05; ∗∗, p < 0.01). (d) Viral load in lungs, ovaries and spleens were examined by qPCR assay. Data are shown as means ± SEM. Statistical significances were calculated by the ordinary one-way ANOVA with Dunnett's multiple comparisons test (∗, p < 0.05; ∗∗, p < 0.01; ∗∗∗, p < 0.001).
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Breman J.G., Steniowski M., Zanotto E., Gromyko A., Arita I. Human monkeypox, 1970-79. Bull World Health Organ. 1980;58(2):165. - PMC - PubMed
    1. Bunge E.M., Hoet B., Chen L., et al. The changing epidemiology of human monkeypox-A potential threat? A systematic review. PLoS Negl Trop Dis. 2022;16(2) - PMC - PubMed
    1. Kalthan E., Tenguere J., Ndjapou S.G., et al. Investigation of an outbreak of monkeypox in an area occupied by armed groups, Central African Republic. Med Mal Infect. 2018;48(4):263–268. - PMC - PubMed
    1. Tan W., Gao G.F. Neglected zoonotic monkeypox in Africa but now back in the spotlight worldwide. China CDC Wkly. 2022;4(38):847–848. - PMC - PubMed
    1. Zhao H., Wang W., Zhao L., et al. The first imported case of monkeypox in the mainland of China - chongqing Municipality, China, September 16, 2022. China CDC Wkly. 2022;4(38):853–854. - PMC - PubMed

MeSH terms

LinkOut - more resources