The impact of long-term moderate level of vaccination coverage for epidemiology of varicella in Lu'an, China: should we change immunisation strategy now?

Abstract

As China implements the voluntary vaccination programme of one-dose of varicella vaccine (VarV) for decades, robust estimates of the impact of voluntary vaccination era on epidemiology of varicella are needed. We estimated the vaccination coverage (VC) of VarV by using surveillance data on immunisation. The descriptive epidemiological method was used to describe the changing epidemiology of varicella from 2007 to 2018. The screening method was used to estimate the vaccine effectiveness (VE) of VarV. The overall VC for VarV was 71.7%, ranged from 47.7% to 79.5% among 2008–2017 birth cohorts. In total, 16 660 varicella cases were reported during 2007–2018, the incidence increased from 10.0 cases per 100 000 population in 2007 to 65.2 cases per 100 000 population in 2018. A shift in age group of varicella was observed since 2012, with the age increased from 5–9 years to 10–14 years. The overall VE was 79.9%, and the VE increased from 60.1% in 2008 birth cohort to 96.2% in 2017 birth cohort. We found that the overall VE for VarV is moderate, but appears highly effective within 5 years after vaccination. In addition, a shift varicella infection to older ages has occurred at the long-term moderate level VC of one-dose VarV. Therefore, to contain the incidence of varicella and prevent any potential shift to older ages, the introduction of VarV into routine immunisation programme is likely needed in Lu'an.

Long-term vaccine efficacy of a 2-dose varicella vaccine in China from 2011 to 2021: A retrospective observational study

“…Our findings also showed that 2-dose VE was increased from 91.80% among birth cohort 2011 to among birth cohort 2014, but it decreased in birth cohort 2015. The reason for this may be related to the coverage rate of 2-dose vaccination ( 36 ), and the VE increase when the vaccination rate increase. Similarly, when vaccination rates in the 2015 birth cohort fell rapidly and VE also declined rapidly.…”

The descriptive epidemiology of coronavirus disease 2019 during the epidemic period in Lu'an, China: achieving limited community transmission using proactive response strategies

“…Although COVID-19 is highly contagious and has spread rapidly from Wuhan throughout China [6], we demonstrated the ability to block transmission and prevented further spread in Lu'an, limiting the impact and the scale of the epidemic. As a city with 5.88 million permanent residents [7], the crude COVID-19 incidence of only 1.4 per 100 000 population during the epidemic period was seemingly acceptable. Here, we summarised the characteristics of the course of the entire epidemic in Lu'an to inform the response for regions with imported cases at the early stage of spread.…”

Persistence of antibodies 5 years after hepatitis B vaccination in preterm birth children: A retrospective cohort study using real‐world data

“…We obtained their current address and vaccination history through the Anhui Immunization Information Management System (AIIMS). The AIIMS is an Internet‐based management platform that maintains immunization data, as described in detail in our previous study 22 . A total of 649 PTB children currently residing in Lu'an were randomly selected and included in the exposure group for this study.…”

“…22 A total of 649 PTB children currently residing in Lu'an were randomly selected and included in the exposure group for this study. After excluding the 96 PTB children who declined to participate in the study, we investigated 553 PTB children and collected their blood samples once they had signed the informed consent form.…”