Evaluation of the cross-neutralization activities elicited by Coxsackievirus A10 vaccine strains

Figures & data

Table 1. List of CV-A10 strains

Name	Cell	Time	Place*	Mean of virus titer (lg CCID50/ml)	LD50(lg CCID50/ml)
Kowalik	RD	1950	USA	7.30	4.80
S101	RD	2014	Fujian Province	8.30	/
S102	Vero	2015	Yunnan Province	8.48	5.83
S103	RD	2016	Jiangsu Province	8.48	/
S104	RD	2016	Jiangsu Province	8.60	1.72
S105	RD	2016	Hubei Province	8.78	0.95
S106	RD	2016	Hubei Province	7.04	/
S107	RD	2017	Guangdong Province	8.00	2.67
S108	Vero	2017	Zhejiang Province	8.30	4.18
S109	RD	2018	Beijing City	8.30	∞
S110	RD	2018	Beijing City	8.48	1.33
S111	RD	2018	Beijing City	8.60	/
S112	RD	2018	Beijing City	8.30	/
S113	Vero	2018	Hubei Province	7.13	/
S114	Vero	2018	Jiangsu Province	7.70	/
S115	RD	2019	Jiangsu Province	8.60	3.00
S116	RD	2019	Hubei Province	8.30	3.64
S117	Vero	2019	Hubei Province	7.96	/

*Kowalik was isolated from USA, others were isolated from mainland China.

Figure 1. Genotyping of the 17 CV-A10 vaccine and detection candidate strains used in this study.

ML tree showed that the 17 CV-A10 strains are of the sub-genotype C3. The names of strains are marked in the figure.

Figure 2. Cross-neutralizing capacity of plasma from humans naturally infected with CV-A10.

The GMTs of 30 human plasma against various strains of CV-A10 ranged from 14.88 to 124.43. This range narrowed down to 1.00–8.36 when GMTs for only strains of sub-genotype C3 were taken into account (shown with black bar). Lastly, the difference between the GMTs for genotype A and sub-genotype C3 strains ranged from 1.47 to 4.91 folds (shown with blue bar).

Figure 3. Cross-neutralizing capacity of sera from murine immunized with CV-A10.

The GMTs of 18 murine sera against various strains ranged from 93.52 to 641.35, of which the discrepancy among strains of sub-genotype C3 was 1.00- to 5.48-fold (shown with black bar), and the difference between genotype A and sub-genotype C3 was 1.25- and 6.86-fold (shown with blue bar).

Table 2. Susceptibility of CV-A10 strains to Neutralization by Murine Sera in vitro.

Murine Sera	CV-A10 strains
	Kowalik	S101	S105	S102	S109	S113	S106	S116	S103	S104	S115	S107	S114	S117	S110	S111	S112	S108
anti-Kowalik	100.00	75.00	800.00	75.00	75.00	37.50	800.00	75.00	600.00	200.00	600.00	75.00	200.00	150.00	200.00	800.00	200.00	150.00
anti-S101	25.00	100.00	75.00	100.00	150.00	50.00	50.00	400.00	150.00	100.00	75.00	600.00	50.00	50.00	75.00	150.00	75.00	200.00
anti-S105	0.15	0.78	100.00	0.59	0.59	0.39	100.00	1.17	100.00	6.25	100.00	1.56	2.34	12.50	3.13	150.00	1.17	1.17
anti-S102	25.00	50.00	37.50	100.00	100.00	50.00	75.00	300.00	50.00	100.00	25.00	200.00	100.00	50.00	75.00	75.00	37.50	150.00
anti-S109	66.67	16.67	50.00	66.67	100.00	200.00	133.33	533.33	50.00	33.33	50.00	400.00	33.33	66.67	50.00	50.00	100.00	100.00
anti-S113	16.67	2.08	3.13	33.33	50.00	100.00	0.78	100.00	2.08	3.13	3.13	100.00	2.08	1.04	3.13	4.17	12.50	133.33
anti-S106	16.67	50.00	200.00	6.25	2.08	33.33	100.00	25.00	400.00	133.33	400.00	16.67	50.00	33.33	133.33	533.33	50.00	33.33
anti-S116	25.00	3.13	3.13	100.00	100.00	100.00	3.13	100.00	1.56	4.17	3.13	400.00	2.08	2.08	4.17	3.13	12.50	266.67
anti-S103	6.25	2.08	400.00	6.25	2.08	1.04	33.33	4.17	100.00	50.00	100.00	3.13	8.33	66.67	12.50	266.67	12.50	6.25
anti-S104	6.25	25.00	9.38	50.00	50.00	25.00	50.00	150.00	37.50	100.00	37.50	150.00	49.88	25.00	75.00	18.75	100.00	100.00
anti-S115	0.39	4.17	100.00	3.13	1.56	1.56	66.67	16.67	100.00	66.67	100.00	8.33	12.50	6.25	33.33	133.33	12.50	6.25
anti-S107	25.00	0.26	0.26	16.67	16.67	25.00	0.78	100.00	0.26	0.26	0.26	100.00	0.26	0.26	0.26	0.26	0.52	100.00
anti-S114	16.67	266.67	400.00	25.00	25.00	4.17	1066.67	50.00	200.00	200.00	400.00	66.67	100.00	400.00	400.00	400.00	200.00	100.00
anti-S117	1.17	9.38	12.50	1.56	2.34	2.34	37.50	3.13	9.38	6.25	6.25	1.56	37.50	100.00	12.50	25.00	9.38	9.38
anti-S110	12.50	33.33	66.67	33.33	12.50	16.67	133.33	66.67	100.00	100.00	66.67	66.67	66.67	66.67	100.00	100.00	100.00	50.00
anti-S111	0.29	0.59	25.00	2.34	1.17	0.05	50.00	4.69	50.00	18.75	200.00	1.56	1.56	9.38	1.17	100.00	1.56	1.17
anti-S112	12.50	33.33	200.00	25.00	16.67	4.17	266.67	100.00	133.33	133.33	266.67	66.67	33.33	16.67	266.67	100.00	100.00	266.67
anti-S108	37.50	50.00	50.00	37.50	50.00	37.50	200.00	300.00	50.00	50.00	75.00	600.00	50.00	50.00	75.00	75.00	150.00	100.00
GMT	8.50	11.17	42.18	17.68	14.91	10.65	53.30	48.43	42.18	31.59	47.35	45.26	17.06	21.84	25.98	58.33	25.33	43.84
MAX/MIN	682.67	1024.00	3072.00	170.67	256.00	4096.00	1365.33	455.11	2304.00	768.00	2304.00	384.00	768.00	1536.00	1536.00	3072.00	384.00	227.56

Table 3. Cross-neutralization ability of Sera from Murine Inoculated with CV-A10 strains

Murine Sera	CV-A10 strains																		GMT	MAX/MIN
	Kowalik	S101	S105	S102	S109	S113	S106	S116	S103	S104	S115	S107	S114	S117	S110	S111	S112	S108
anti-Kowalik	256	192	2048	192	192	96	2048	192	1536	512	1536	192	512	384	512	2048	512	384	471.31	21.33
anti-S101	8	32	24	32	48	16	16	128	48	32	24	192	16	16	24	48	24	64	31.61	24.00
anti-S105	24	128	16384	96	96	64	16384	192	16384	1024	16384	256	384	2048	512	24576	192	192	715.20	1024.00
anti-S102	256	512	384	1024	1024	512	768	3072	512	1024	256	2048	1024	512	768	768	384	1536	726.72	12.00
anti-S109	256	64	192	256	384	768	512	2048	192	128	192	1536	128	256	192	192	384	384	296.91	32.00
anti-S113	256	32	48	512	768	1536	12	1536	32	48	48	1536	32	16	48	64	192	2048	137.45	170.67
anti-S106	64	192	768	24	8	128	384	96	1536	512	1536	64	192	128	512	2048	192	128	205.27	256.00
anti-S116	384	48	48	1536	1536	1536	48	1536	24	64	48	6144	32	32	64	48	192	4096	200.12	256.00
anti-S103	24	8	1536	24	8	4	128	16	384	192	384	12	32	256	48	1024	48	24	58.91	384.00
anti-S104	512	2048	768	4096	4096	2048	4096	12288	3072	8192	3072	12288	4086	2048	6144	1536	8192	8192	3523.63	24.00
anti-S115	96	1024	24576	768	384	384	16384	4096	24576	16384	24576	2048	3072	1536	8192	32768	3072	1536	3305.86	341.33
anti-S107	384	4	4	256	256	384	12	1536	4	4	4	1536	4	4	4	4	8	1536	31.40	384.00
anti-S114	64	1024	1536	96	96	16	4096	192	768	768	1536	256	384	1536	1536	1536	768	384	466.88	256.00
anti-S117	12	96	128	16	24	24	384	32	96	64	64	16	384	1024	128	256	96	96	78.38	85.33
anti-S110	48	128	256	128	48	64	512	256	384	384	256	256	256	256	384	384	384	192	208.58	10.67
anti-S111	24	48	2048	192	96	4	4096	384	4096	1536	16384	128	128	768	96	8192	128	96	338.64	4096.00
anti-S112	768	2048	12288	1536	1024	256	16384	6144	8192	8192	16384	4096	2048	1024	16384	6144	6144	16384	4019.40	64.00
anti-S108	48	64	64	48	64	48	256	384	64	64	96	768	64	64	96	96	192	128	98.76	16.00

Figure 4. Antigenic map of 18 anti-sera against 18 strains.

The relative positions of viral strains (blue points) and anti-sera (gray points) were adjusted such that the distances between strains and anti-sera in the map represent the corresponding neutralization titers. Outer circles of strains mean standard error. The space between grid lines is 1 unit of antigenic distance, corresponding to a 2-fold dilution of antiserum in the neutralization assay.

Figure 5. Cross-protective effect of anti – S102 against lethal challenge of 8 CV-A10 strains.

Diluted anti-S102 (16-fold) showed discrepant protective effect against 8 CV-A10 strains, and it ascended from 50% to 100% in the order S107, S115, S110, S105, S116, S108, S102, and Kowalik, with protection against S107 and S116 being both 50% and that against Kowalik being 100%.