Improved timely birth dose coverage of hepatitis B vaccine narrows the socio-economic inequality in western China in 2011–2016

ObjectiveTo compare timely birth dose (TBD) coverage of hepatitis B vaccine and socio-economic inequality distribution of TBD coverage between 2011 and 2016 in rural areas of western China.MethodsIn western China, using multi-stage probability proportion to size sampling, 2633 and 1929 children aged 0–35 months with an immunization card were selected from 14 rural counties in 2011 and 2016, respectively. Socio-economic characteristics were obtained from face-to-face questionnaire survey and copies of vaccination certificates. We performed multivariate logistic regression models to identify the determinants of TBD coverage of hepatitis B vaccine. We grouped TBD coverage by wealth quintiles, calculated inequality using the difference base on coverage in richest (quintile 5) and poorest (quintile 1) household wealth quintiles.FindingsFrom 2011 to 2016, the overall TBD coverage of hepatitis B vaccine among children aged 0–35 months in rural areas of western China increased from 52.8% (95% confidence interval, CI: 42.4–62.8) to 80.2% (95% CI: 69.5–87.8). The absolute difference in TBD coverage between richest and poorest quintiles was 20.6 (95%CI: 9.4–31.8) and 15.8 (95%CI: 1.4–30.2) in 2011 and 2016, respectively.ConclusionThe socioeconomic inequality in TBD coverage decreased over the study period, but such inequality still existed in 2016. To improve inequality in TBD, the government should pay more attention to the disadvantaged groups, especially the children who were delivered at home, or whose caregivers were ethnic minority or who have a lower level of education.     

The long-term efficacy, 13–23 years,of a plasma-derived hepatitis B vaccine in highly endemic areas in China

ObjectiveTo evaluate the long-term effectiveness of the plasma-derived hepatitis B vaccine that has been applied widely in five areas of China where HBV prevalence was highly endemic.MethodA cross-sectional investigation was conducted in 2009 at five HBV surveillance sites around China. The target study subjects of 6772 were born between 1986 and 1996 and received plasma-derived HBV vaccine. Serum samples were collected to test for HBV markers using the microparticle enzyme immunoassay.ResultsThe number of participants enrolled was 6772. The average hepatitis B surface antigen (HBsAg) prevalence was 2.01%. The birth dose group included 5052 children. In this group, the average positive rates of HBsAg and hepatitis B core antibody (anti-HBc) were 1.58% and 6.39%, respectively, and these values declined gradually from 1986 to 1996. The positive rates of anti-hepatitis B surface antibody (HBs) and the geometric mean concentration (GMC) of anti-HBs-positive subjects were 41.69% and 115.8 mIU/ml.ConclusionThe long-term effectiveness of the plasma-derived hepatitis B vaccine still provided protection 13–23 years after vaccination. It seems that a booster dose is not necessary. Enhancing the rate of the birth dose within 24 h is one of the most important measures to prevent and control HBV infection.     

Molecular epidemiology and genetic evolution of canine parvovirus in East China,during 2018‐2020

Canine parvovirus type 2 (CPV-2) emerged in the late 1970s, which caused high rates of morbidity and mortality in dogs. In last decade, five genetic variants (CPV-2a, CPV-2b, CPV-2c, New CPV-2a, and New CPV-2b) were frequently reported in the dog population, and replaced the original CPV-2, rising widespread concerns. However, little is known about their recent genetic diversity and evolution. The aim of this study was to analyze the characteristics of the CPV-2 strains collected in East China from 2018 to 2020. The 57 CPV-2 strains were isolated from rectal swab samples (n=140). They belong to three different genotypes, based on VP2 protein amino acid sequence. The results revealed a high prevalence of CPV-2c (77.19%) compared to the New CPV-2a (5.26%) and New CPV-2b (17.54%) strains. Further analysis showed that nucleotide homology of the VP2 gene among the 57 CPV strains was 98.9%~100%, and the homology with 24 reference strains from different countries and regions was 98.1%~100%. The phylogenetic tree of VP2 gene sequence showed that 44 CPV-2c strains were distantly related to CPV-2, CPV-2a, CPV-2b, New CPV-2a, New CPV-2b and European/American CPV-2c strains, and were closely related to Asian CPV-2c strains. The results showed that these Asian CPV-2c strains had become the dominant strain, which renewed the knowledge of CPV-2 molecular epidemiology in East China.     

Factors associated with effectiveness of the first dose of hepatitis B vaccine in China: 1992–2005

Background

In China, the prevalence of chronic hepatitis B infection was high because of perinatal and early childhood transmission. A three-dose hepatitis B vaccine schedule with a first dose as soon as possible after birth was introduced in 1992 and generalized in 2002 in the Expanded Programme of Immunization (EPI). In 2006, a serological survey evaluated the effectiveness of vaccination.

Methods

We conducted a restricted analysis of the national serological survey that sampled children and collected information on demographic characteristics, birth history, hepatitis B vaccination and hepatitis B surface antigen (HBsAg) status as determined by ELISA testing. We compared children who received the first dose in a timely way (i.e., within 24 h of birth) with others in terms of HBsAg status, stratified by birth cohort and place of birth.

Results

Three-dose hepatitis B vaccine coverage increased from 60.8% for children born in 1992–1997 to 93.2% for children born in 2002–2005. Meanwhile, timely birth dose coverage increased from 38.7% to 74.4%. Among 29,410 children born in 1992–2005 who had received three vaccine doses and no hepatitis B immune globulin, factors associated with being HBsAg-negative in multivariate analysis included receiving a timely birth dose (p = 0.04), birth after 1998 (p < 0.001), living in an urban setting (p = 0.008) and hospital birth (p = 0.001). The relative prevalence of HBsAg among children receiving the timely birth dose was lower for children born in county or larger hospitals (0.39), intermediate in township hospitals (0.73) and highest at home (0.87).

Conclusions

Hospital birth and receiving a timely birth dose are the main determinants of the field effectiveness of the first dose of hepatitis B vaccine. Efforts to increase the proportion of hospital deliveries are key to increasing timely birth dose coverage and its effectiveness.     

Molecular epidemiology and genetic characterization of influenza B virus in Lebanon during 2016–2018

BackgroundInfluenza B viruses are a major cause of serious acute respiratory infections in humans.MethodsNasopharyngeal swabs were collected from subjects with influenza-like illness during October 2016–June 2018 and screened for influenza A and B. The hemagglutinin (HA) and neuraminidase (NA) genes of the Lebanese influenza B specimens were sequenced and phylogenetically compared with the vaccine strains and specimens from the Eastern Mediterranean Region and Europe.ResultsInfluenza A and B viruses co-circulated between October and May and peaked between January and March. During the 2016–2017 season, A/H3N2 (33.4%) and B/Yamagata (29.7%) were the predominantly circulating viruses followed by B/Victoria and A/H1N1pdm09 viruses. During the 2017–2018 season, A/H3N2 (31.5%) and A/H1Npdm09 (29.3%) were most prevalent with co-circulation of B/Yamagata and to a lesser extent B/Victoria viruses. The B/Yamagata specimens belonged to clade-3 while the B/Victoria belonged to clade-1A. None of the analyzed specimens had a mutation known to confer resistance to NA inhibitors (NAIs).ConclusionMultiple subtypes of influenza co-circulate each year in Lebanon with a peak between January and March. The trivalent vaccine included a B/Victoria strain which mismatched the B/Yamagata lineage that predominated during the study period, highlighting the importance of quadrivalent vaccines.     

Media and public reactions toward vaccination during the ‘hepatitis B vaccine crisis’ in China

BackgroundPublic disputations affected vaccine confidence and vaccine rates particularly when adverse events occur. The vigorous development of Internet in China provides an opportunity to observe public reaction and sentiment toward vaccination when Kangtai Hepatitis B vaccine crisis happened and evolved to a widespread debate on the internet from December 12, 2013 to January 3, 2014.MethodsThis study conducted Internet surveillance by examining three daily indicators including the daily number of relevant online news article, Sina Weibo posts and Baidu search index during the crisis. We also analyzed the sentiments of relevant original microblog posts collected from Sina Weibo platform in the crisis.ResultsA total of 17 infant deaths were reported to associated with Hepatitis B vaccination. Three major waves of high media and public attention were detected. The daily indicators reached their peaks in the second wave after the relevant vaccine was suspended by the authority (from December 20 to December 29, 2013) with 23,200 daily online news reports, 34,018 Sina Weibo posts and 17,832 Baidu search indices. There were significant correlations between the daily amount of online news, Weibo posts, and Baidu searches (p < .001). The contents analysis suggested 1343 out of 1608 (83.5%) original Weibo posts expressed negative sentiment with almost 90% in the second wave.ConclusionThis study found the Kangtai vaccine crisis raised great public attention and negative sentiment toward vaccinations on the internet in China. Policy change such as suspension of the suspected vaccine might trigger even greater reaction and more negative sentiment. The government should provide ways to address emerging public concerns after policy change to avoid misinformation and misunderstanding during such a vaccine crisis.     

Immunity to hepatitis B persists in adolescents 15–16 years of age vaccinated in infancy with three doses of hepatitis B vaccine

ObjectiveVaccination of infants against hepatitis B virus (HBV) using hepatitis B vaccine is effective in preventing the infection during early childhood and there is a growing evidence of long-term protection. So far, no need for a booster dose has been identified in healthy subjects; however further follow-up continues to determine the exact duration of protection. We evaluated antibody persistence and immune response to a hepatitis B vaccine challenge dose in children aged 15–16 years, previously vaccinated with 3-doses of the same vaccine in infancy (third dose received before 18 months of age).MethodsA single hepatitis B vaccine challenge dose containing 10 μg hepatitis B surface (HBs) antigen was administered to adolescents aged 15–16 years. Blood samples were taken before and one month after the challenge dose to measure anti-HBs antibodies using a chemiluminescence immunoassay. Solicited local and general symptoms, as well as unsolicited and serious adverse events were recorded after the challenge dose.Results303 subjects were enrolled, of whom 302 and 293 subjects formed the total vaccinated and according-to-protocol cohorts, respectively. Pre-challenge, 65.4% (95% CI: 59.6–70.9) subjects were seroprotected (anti-HBs antibody concentration ≥10 mIU/mL). One month post-challenge, 97.9% (95% CI: 95.6–99.2) were seroprotected, while 90.8% (95% CI: 86.8–93.8) had anti-HBs antibody concentrations ≥100 mIU/mL. The post-challenge geometric mean concentration (GMC; 4134.9 [95% CI: 3114.2–5490.1]) was 150-fold higher than the pre-challenge GMC. Overall, 96.9% (95% CI: 94.2–98.6) subjects mounted an anamnestic response. The safety and reactogenicity profile of the hepatitis B vaccine challenge dose was consistent with previous experience.ConclusionsImmunity to hepatitis B persists in 15–16 year old adolescents following primary vaccination in infancy.Trial registrationhttp://www.clinicaltrials.gov NCT01847430.     

Molecular evolution of Japanese encephalitis virus isolates from swine in Oita,Japan during 1980–2009

In order to identify the patterns of genetic change of Japanese encephalitis virus (JEV) strains circulating in Oita, the complete envelope (E) gene has been sequenced for 35 isolates from swine in a 30-year span. Based on nucleotide and deduced amino acid sequences, the genetic variation was examined, phylogeny was estimated and selection pressures were also analyzed. This study demonstrated that the major genotype (G) of JEV isolates had shifted from GIII to GI in the mid-1990s in Oita. The intensities of selection acting on the Oita GIII and GI strains were found to be almost same. It suggests that the intensity of selection might not be the reason for such a genotype shift observed in Oita. Pairwise comparisons revealed the high conservation of the E gene at the protein level. Compared with the Oita GIII strains, all the Oita GI strains shared four amino acid changes at E129 (T–M), E222 (A–S), E327 (S–T) and E366 (A–S). Among all 70 JEV isolates involved in this paper, the GI strains shared only one amino acid change at E222 (A–S) in comparison with the GIII strains. No strong evidence for positive selection was found, the JEV evolution has generally been subject to strong purifying selection, but one ongoing evolutionary pathway was found to be under relaxed purifying selection in Oita. This study is a localized example of JEV molecular evolution in nature.     

Assessment of the duplicate notifiable reporting of hepatitis B infection in Zhejiang province,China, 2005–2015

BackgroundHepatitis B virus (HBV) infection control has seen improvements since the introduction of the HBV vaccination program in China. However, the reported incidence rate of HBV infection remains high owing to the large pool of individuals infected before the start of the HBV immunization program. The duplicated reporting of HBV had a remarkable effect on the overestimation of HBV disease burden, according to the Chinese National Notifiable Diseases Report System (NNDRS).MethodsWe analyzed the data of HBV in Zhejiang province, China, collected for the years 2005–2015 from the NNDRS. The duplicate reporting cases of HBV were captured according to the same identification number or the same name, sex and date of birth, or the same name, sex and resident town/street code. We assessed the magnitude of duplicated reporting of HBV and explored the possible factors contributing to duplicated reporting.ResultsThere were 20,078 redundant HBV cases reported from the NNDRS during 2005–2015, which accounted for 6.33% (19,272/305,654) of all patients owing to duplicate reporting in Zhejiang province, China. Some risk factors, including male sex, age ≥20 years, chronic cases, residence in outside counties, and farming as an occupation (odds ratio [OR] = 1.06; 95% confidence interval [CI]: 1.02–1.11) were positively associated with the risks on duplicate reporting.ConclusionsOur results demonstrated that the duplicated reporting of HBV infection is common in Zhejiang, China, which has contributed to a higher HBV infection prevalence than its real value. Some characteristics might affect the probability of duplicate reporting, including sex, occupation, place of residence, HBV type, and hospital type. These findings indicated the strong need to improve the data collection, deletion of duplications, and HBV classification during HBV surveillance, in order to obtain an accurate estimate of HBV disease burden in China. We also suggest establishing a specialized system to achieve high-quality HBV infection surveillance effectively and practically.     

Epidemiological distribution of hepatitis B virus genotypes in 1–29-year-olds in the mainland of China

BackgroundTo analyze the epidemiological distribution of Hepatitis B virus (HBV) genotype in the mainland of China following the implementation of effective preventive measures.MethodsFive hundred and seventeen HBsAg-positive subjects aged 1–29 years surveyed in the 2014 national HBV sero-survey in the mainland of China were enrolled in the study. The full-length HBV genome was obtained by PCR amplification and sequencing. The HBV genotype was determined by phylogenetic analysis. Combined with questionnaire information, HBV genotype distribution was analyzed.ResultsOf the 517 HBsAg-positive subjects, 369 (71.4%) were included in the analysis. HBV genotypes found were B (45.0%), C (36.6%), D (6.0%), C/D (9.8%), B/C (2.2%), and I (0.5%). Geographic differences in HBV genotype were significant for seven regions. Three serotypes were found: adw (47.2%), adr (35.5%), and ayw (17.3%). B2 (43.9%) and C2 (25.2%) were the two major subgenotypes. The predominant genotypes differed between the Han group and the other ethnic groups. No statistical differences in genotype distribution were found by gender, age group, or hepatitis B (HepB) vaccination history.ConclusionThe prevalence of HBV genotype B was higher than that of genotype C with subgenotypes B2 and C2 endemic in 1–29-year-olds in the mainland of China, after HBV prevalence has reduced significantly due to the implementation of preventive measures. HepB vaccination or other factors did not interfere with HBV genotype distribution. The surveillance of HBV genotype was essential for responding to the potential changes and impact on the preventive policies in the future.     

Molecular surveillance of rubella virus in Beijing,China during 2010–2021: Progress and challenges in rubella elimination

Rubella is listed by the World Health Organization (WHO) as a disease that needs to be eliminated worldwide. The aim of this study was to understand the progress and challenges towards rubella elimination in Beijing, China, by analyzing molecular surveillance data combined with immunization and surveillance strategies as well as epidemiological data. With high immunization coverage under the 3-dose policy (8 months, 18 months, and 6 years) and supplementary immunization activities for the floating population, rubella incidence showed a downward trend since 2010, despite two epidemics that occurred in 2014–2015 and 2019. The reported rubella cases were generally concentrated in the age group of 15–34 years. Although citywide surveillance for congenital rubella syndrome (CRS) has been carried out since 2016, only one case has been confirmed by laboratory testing. Furthermore, molecular surveillance data showed that rubella viruses (RVs) circulating in Beijing during 2010–2020 were evidently heterogeneous; the domestic lineage 1E-L1 and multiple imported lineages, including 2B-L1, 1E-L2, and 2B-L2c, were identified in the last decade. Meanwhile, two lineage-related switches were determined, including the displacement of lineage 1E-L1 with lineage 2B-L1 around 2014 and the transition between lineage 2B-L1 and lineage 1E-L2 and 2B-L2c in 2018–2019. This RV transmission pattern was similar to that observed across the country, whereas lineages 1E-L1 and 2B-L2c were prevalent in Beijing for a shorter period. Overall, these results indicate the need to maintain routine immunization with rubella-containing vaccines, promote regular supplementary immunization activities, and enhance rubella and CRS surveillance even in order to accelerate rubella elimination in Beijing. Further, the existing immunization strategies must be optimized to further close the immunity gap.     

Incremental system costs of introducing combined DTwP–hepatitis B–Hib vaccine into national immunization services in Ethiopia

Objective

With support from the GAVI Alliance a fully liquid combined DTwP–HepB–Hib (pentavalent) vaccine in a single dose vial was introduced into Ethiopia's routine immunization services in March 2007. This vaccine was substituted with DTwP in a 10-dose vial. We aimed to estimate the incremental system costs of pentavalent vaccine delivery.

Methods

Data on cold storage expansion and increased vaccine transport frequency were collected in four regions of Ethiopia over a 2-week period, as part of a Post-Introduction Evaluation of the new vaccine. Interviews were conducted with individuals at all levels of the health system. Information on the costs of training and communication to facilitate the introduction was collected from the Ministry of Health, UNICEF and WHO in Addis Ababa.

Results

The switch from a 10-dose DTwP to a single dose pentavalent vaccine increased refrigeration storage volume per fully vaccinated child by 106% at national and regional levels and by 71% at the three lower levels of vaccine distribution. Cold storage equipments were purchased at all levels and the frequency of vaccine collection more than doubled in many places. Incremental capital costs of cold storage equipment, training and communication amounted to US$ 4.8 million, or US$ 1.53 per child in the 2007 birth cohort. After annualizing capital costs and adding recurrent costs, system costs came to US$ 0.80 per child in the 2007 birth cohort. With a vaccination coverage rate of 78% this is equivalent to US$ 1.13 per fully vaccinated child. The most important system cost item is cold storage, amounting to US$ 0.62 per child in the birth cohort and US$ 0.03 per additional cm³ of cold storage.

Conclusion

In Ethiopia introduction of pentavalent vaccine necessitated considerable investments in additional cold storage equipment as well as an increase in vaccine transport frequency. A GAVI Alliance introduction grant of US$ 0.30 per child in the birth cohort would cover approximately 20% of the capital investments undertaken to facilitate introduction.     

A multi-country investigation of influenza vaccine coverage in pregnant individuals, 2010–2016

BackgroundMany countries recommend influenza vaccination during pregnancy. Despite this recommendation, influenza vaccine among pregnant individuals remains under-utilized and uptake varies by country. Factors associated with influenza vaccine uptake during pregnancy may also vary across countries.MethodsAs members of the Pregnancy Influenza Vaccine Effectiveness Network (PREVENT), five sites from four countries (Australia, Canada, Israel, and the United States) retrospectively identified cohorts of individuals aged 18–50 years who were pregnant during pre-defined influenza seasons. Influenza vaccine coverage estimates were calculated for the 2010–11 through 2015–16 northern hemisphere and the 2012 through 2015 southern hemisphere influenza seasons, by site. Sites used electronic health records, administrative data, and immunization registries to collect information on pregnancy, health history, demographics, and vaccination status. Each season, vaccination coverage was calculated as the percentage of individuals who received influenza vaccine among the individuals in the cohort that season. Characteristics were compared between those vaccinated and unvaccinated, by site.ResultsMore than two million pregnancies were identified over the study period. Influenza vaccination coverage ranged from 5% to 58% across sites and seasons. Coverage increased consistently over the study period at three of the five sites (Western Australia, Alberta, and Israel), and was highest in all seasons at the United States study site (39–58%). Associations with vaccination varied by country and across seasons; where available, parity >0, presence of a high-risk medical condition, and urban residence were consistently associated with increased likelihood of vaccination.ConclusionsThough increasing, uptake of influenza vaccine among pregnant individuals remains lower than recommended. Coverage varied substantially by country, suggesting an ongoing need for targeted strategies to improve influenza vaccine uptake in this population.     

Genetic diversity and molecular evolution of human adenovirus serotype 41 strains circulating in Beijing,China, during 2010–2019

Human adenovirus serotype 41 (HAdV-F41) is an important pathogen that causes diarrhea in children. However, the data on its molecular genetic characteristics and evolutionary history are still neither comprehensive nor sufficient. Four capsid protein genes from 58 HAdV-F41-positive specimens taken from diarrheal children in Beijing during 2010–2019 were amplified and analyzed. Variant amino acids in the hexon gene (18 sites) and short fiber gene (4 sites) clustered these strains into two clades and four subclades. The deletion of 15 amino acids found in the gene seemed to have little effect on the genomic strain cluster same as to penton gene. The HAdV-F41 strains had high diversity, as assessed from the intraspecific recombination of hexon, short fiber and long fiber. The molecular evolutionary rate of HAdV-F41's concatenated genes was 4.07 × 10⁻⁵ substitutions/site/year, and it diverged from the most recent common ancestor in 1720. Apart from in the penton gene, positive selection codons were predicted in the other three genes, which may play a synergistic role in the evolution of HAdV-F41. These results provide new insights for understanding the characteristics of infectivity and developing vectors and vaccine vehicles for HAdV-F41.     

Influenza vaccine effectiveness against medically-attended influenza illness during the 2012–2013 season in Beijing,China

Background

Influenza vaccine coverage remains low in China, and there is limited information on the preventive value of local vaccination programs.

Methods

As part of influenza virological surveillance in Beijing, China during the 2012–2013 influenza season, we assessed the vaccine effectiveness (VE) of one or more doses of trivalent inactivated influenza vaccine (IIV3) in preventing medically-attended influenza-like-illness (ILI) associated with laboratory-confirmed influenza virus infection using a test-negative case–control design. Influenza vaccination was determined based on self-report by adult patients or the parents of child patients.

Results

Of 1998 patients with ILI, 695 (35%) tested positive for influenza viruses, including 292 (42%) A(H3N2), 398 (57%) A(H1N1)pdm09, and 5 (1%) not (sub)typed influenza viruses. The rate of influenza vaccination among all patients was 4% (71/1998). Among influenza positive patients, 2% (57/1303) were vaccinated compared to 4% (14/695) among influenza negative patients, resulting in VE for one or more doses of vaccine (adjusted for age, sex, week, and days since illness onset) against all circulating influenza viruses of 52% (95% CI = 12–74%). A significant adjusted VE for one or more doses of vaccine for all ages against A(H1N1)pdm09 of 59% (95% CI, 8–82%) was observed; however, the VE against A(H3N2) was 43% (95% CI, −30% to 75%). The point estimate of VE was 59% (95% CI, 19–79%) for those aged <60 years, but a negative VE point estimate without statistical significance was observed among those aged ≥60 years.

Conclusions

IIV3 conferred moderate protection against medically-attended influenza in Beijing, China during the 2012–2013 season, especially against the A(H1N1)pdm09 strain and among those aged <60 years old.     

Sustained impact of rotavirus vaccine on rotavirus hospitalisations in Lusaka,Zambia, 2009–2016

BackgroundMonovalent rotavirus vaccine (RV1) was introduced in Lusaka in February 2012 and rolled out countrywide in November 2013 in the routine Expanded Programme on Immunisation and administered at 6 and 10 weeks with no catch up dose. Reported here is the monitoring of rotavirus acute gastroenteritis hospitalisations at the University Teaching Hospital, Lusaka, Zambia as part of efforts to document the impact of rotavirus vaccine.MethodsChildren <5 years hospitalised for acute gastroenteritis (AGE) from January 2009 to December 2016 were recruited into the rotavirus disease burden active surveillance and had their stools tested for rotavirus by enzyme immunoassay. We compared rotavirus-associated AGE hospitalisations of the pre-vaccine era (2009–2011) with the post-rotavirus vaccine introduction period (2013–2016).ResultsWith the increase in RV1 coverage in Lusaka, rotavirus AGE declined significantly from 40% of diarrhoea hospitalisation in the pre-vaccine era to 29% of diarrhoea hospitalisation in the post-vaccine era (p < 0.001) in children <5 years. After a decreasing trend in rotavirus positivity from 2013 to 2015, positivity increased to 37% in 2016. However, the post-vaccine years (2012–2016) saw substantial decline in the number tested (median decline: 34% (range: 20–43%)) and the number of positive results (median decline: 52% (range: 30–65%).ConclusionA sustained and significant decline in rotavirus AGE hospitalisations was observed in children <5 years since the introduction of RV1 in Lusaka, Zambia. Despite an increase in rotavirus positivity in 2016, the total number of children enrolled and the number of rotavirus positive children remained below baseline. The reason for the increase in rotavirus positivity in 2016 is unknown but could be due to an accumulation of susceptible children and the shifting of disease to children of older age groups. This finding underscores the need for continued monitoring of rotavirus vaccine impact.     

Detection and spike gene characterization in porcine deltacoronavirus in China during 2016–2018

Porcine deltacoronavirus (PDCoV) has been emerging in several swine-producing countries for years. In our study, 719 porcine diarrhoea samples from 18 provinces in China were collected for PDCoV and porcine epidemic diarrhoea virus (PEDV) detection. The epidemiological survey revealed that the positive rates of PDCoV, PEDV and coinfection were 13.07%, 36.72% and 4.73%, respectively. The entire spike (S) genes of eleven detected PDCoV strains were sequenced. Phylogenetic analysis showed that the majority of PDCoVs could be divided into three lineages: the China lineage, the USA/Japan/South Korea lineage and the Viet Nam/Laos/Thailand lineage. The China and the Viet Nam/Laos/Thailand lineages showed much greater genetic divergences than the USA/Japan/South Korea lineage. The present study detected one new monophyletic branch that contained three PDCoVs from China, and this branch was separated from the China lineage but closely related to the Viet Nam/Laos/Thailand lineage. The strain CH-HA2-2017, which belongs to this new branch, had a possible recombination event between positions 27 and 1234. Significant amino acid substitutions of PDCoV S proteins were analysed and displayed with a three-dimensional cartoon diagram. The visual spatial location of these substitutions gave a conformational-based reference for further studies on the significance of critical sites on the PDCoV S protein.     

Assessing the safety of hepatitis B vaccination during pregnancy in the Vaccine Adverse Event Reporting System (VAERS), 1990–2016

BackgroundThe safety of hepatitis B vaccination during pregnancy has not been well studied.ObjectiveWe characterized adverse events (AEs) after hepatitis B vaccination of pregnant women reported to the Vaccine Adverse Event Reporting System (VAERS), a spontaneous reporting surveillance system.MethodsWe searched VAERS for AEs reports involving pregnant women who received hepatitis B vaccine from January 1, 1990–June 30, 2016. All reports and available medical records were reviewed by physicians. Observed AEs were compared to expected AEs and known rates of pregnancy outcomes to assess for any unexpected safety concern.ResultsWe found 192 reports involving pregnant women following hepatitis B vaccination of which 110 (57.3%) described AEs; 12 (6.3%) were classified as serious; one newborn death was identified in a severely premature delivery, and there were no maternal deaths. Eighty-two (42.7%) reports did not describe any AEs. Among pregnancies for which gestational age was reported, most women were vaccinated during the first trimester, 86/115 (74.7%). Among reports describing an AE, the most common pregnancy-specific outcomes included spontaneous abortion in 23 reports, preterm delivery in 7 reports, and elective termination in 5 reports. The most common non-pregnancy specific outcomes were general disorders and administration site conditions, such as injection site and systemic reactions, in 21 reports. Among 22 reports describing an AE among infants born to women vaccinated during pregnancy, 5 described major birth defects each affecting different organ systems.ConclusionOur analysis of VAERS reports involving hepatitis B vaccination during pregnancy did not identify any new or unexpected safety concerns.     

Immunogenicity of an investigational hepatitis B vaccine with a toll-like receptor 9 agonist adjuvant (HBsAg-1018) compared with a licensed hepatitis B vaccine in subpopulations of healthy adults 18–70 years of age

BackgroundImmunologic response to a complete vaccine regimen of currently licensed alum-adjuvanted hepatitis B vaccines is reduced in several subpopulations, including older adults, men, obese persons, and smokers. Two phase 3 trials in healthy adults demonstrated that 2 doses over 1 month of an investigational hepatitis B vaccine (HBsAg-1018) induced superior seroprotection rates (SPRs) to 3 doses over 6 months of the licensed vaccine Engerix-B^® (HBsAg-Eng).MethodsAn exploratory analysis of immunogenicity was conducted in subpopulations from pooled data for the 2 phase 3 trials.ResultsIn each subpopulation, the peak SPR in the HBsAg-1018 group was statistically significantly higher than the peak SPR in the HBsAg-Eng group. Peak HBsAg-1018 SPRs ranged from 91.6% to 99.7%, while peak HBsAg-Eng SPRs ranged from 67.7% to 92.9%.ConclusionIn these exploratory analyses, 2 doses of HBsAg-1018 induced statistically significantly higher rates of seroprotection than 3 doses of HBsAg-Eng across all subpopulations.