Vaccination coverage estimates and utilization patterns of inactivated enterovirus 71 vaccine post vaccine introduction in Ningbo, China

Abstract

Background In China, enterovirus 71 (EV71) is the major etiological agents of hand foot mouth disease that poses severe risks to children’s health. Since 2015, three inactivated EV71 vaccines have been approved for use. Previous studies indicated the high willingness of EV71 vaccination in eastern China. However, few studies have assessed coverage and utilization patterns of EV71 vaccine in China. Methods Children born during 2012–2018 were sampled and their records were abstracted from Ningbo childhood immunization information management system. Descriptive statistics characterized the study population and assessed coverage and timeliness for EV71 vaccination. Simultaneous administration patterns as well as type of EV71 vaccine used were also evaluated. Bivariate and multivariable analysis was used to examine the relationship of socio-demographic characteristics with vaccination coverage and timeliness. Results Of 716,178 children living in Ningbo. One hundred seventy-two thousand two hundred thirty-six received EV71 vaccine with a coverage rate of 24.05% and only 8.61% received vaccination timely. 21.97% of children received the complete two dose EV71 series but only 6.49% completed timely. Vaccination coverage and timeliness increased significantly from 2012 birth cohort to 2018 birth cohort. Relatively higher coverage and timeliness were observed in resident children, Inner districts, high socioeconomic areas and large-scaled immunization clinics. Of 329,569 doses of EV71 vaccine, only 5853(1.78%) doses were administered at the same day as other vaccines. Conclusions There is a need for increasing EV71 vaccination coverage and timeliness as well as eliminating disparities among different populations. Our study highlights the importance of simultaneous administration to increasing coverage and timeliness of EV71 vaccination.

Spatial–temporal-demographic and virological changes of hand, foot and mouth disease incidence after vaccination in a vulnerable region of China

“…We have shown high newborn-completion-vaccination rates (71.33% in 2018) in Hefei while Guangzhou had a 15.11% rate in 2018 [ 42 ]. In Ningbo, the newborn-completion-vaccination rate was 44.23% [ 43 ], and the incidence density was as high as 5 945.50/10 5 person-years [ 33 ]. Countries such as Japan and Singapore also have a high prevalence of HFMD, but did not use the EV-A71 vaccine, although EV-A71 prevalence dropped in 2015 but subsequently increased thereafter [ 44 , 45 ].…”

“…Therefore, future attention should be focused to continuously improve maintenance of vaccination. Notably, the guidelines recommend completion of EV-A71 with two doses before 12 months of age suggesting timeliness was considered to be an indicator of the effectiveness of EV71 vaccine [ 43 , 46 ].…”

Study on the interaction between different pathogens of Hand, foot and mouth disease in five regions of China

“…The optimal age for EV-A71 vaccination is from 6 months to 71 months of age, and full vaccination is encouraged to be completed before the infant reaches 12 months of age ( 41 ). The current coverage of EV-A71 vaccine in China is not very high as the previous researches showed that the vaccination coverage rate in Guangdong Province was rose from 3.82 to 10.07% in 2016 and 2017 ( 42 ), and the EV71 vaccination rate in Ningbo City was 24.05% among 716,178 children born from 2012 to 2018, with a timely vaccination rate of only 8.61% ( 43 ). In Kunming, a central city in southwest China, about 19.16% of children were vaccinated in 2018.…”

Spatiotemporal cluster patterns of hand, foot, and mouth disease at the province level in mainland China, 2011–2018

“…In 2018, the incidence in Zhejiang and Jiangsu reached the highest value after the vaccine was launched, which was 436.02 per 100,000 in Zhejiang and 237.50 per 100,000 in Jiangsu, and Zhejiang had the highest incidence in the country. EV-A71 vaccine coverage rate had increased year by year to 24.05% in Zhejiang, higher than 19.4% in Guangdong [ 77 ]. The proportion of EV-A71 positive cases declined from 22.6% in 2017 to 3.3% in 2018 in Zhejiang [ 78 ].…”