The effect of maternal antibodies on the cellular immune response after infant vaccination: A review

During the last few decades, maternal immunization as a strategy to protect young infants from infectious diseases has been increasingly recommended, yet some issues have emerged. Studies have shown that for several vaccines, such as live attenuated, toxoid and conjugated vaccines, high maternal antibody titers inhibit the infant’s humoral immune response after infant vaccination. However, it is not clear whether this decreased antibody titer has any clinical impact on the infant’s protection, as the cellular immune responses are often equally important in providing disease protection and may therefore compensate for diminished antibody levels. Reports describing the effect of maternal antibodies on the cellular immune response after infant vaccination are scarce, probably because such studies are expensive, labor intensive and utilize poorly standardized laboratory techniques. Therefore, this review aims to shed light on what is currently known about the cellular immune responses after infant vaccination in the presence of high (maternal) antibody titers both in animal and human studies. Overall, the findings suggest that maternally derived antibodies do not interfere with the cellular immune responses after infant vaccination. However, more research in humans is clearly needed, as most data originate from animal studies.     

The burden of herpes zoster disease in Norway

BackgroundNo national vaccination program against herpes zoster (HZ) is currently in place in Norway. We aimed to quantify the burden of medically attended HZ to assess the need for a vaccination program.MethodsWe linked data from several health registries to identify medically attended HZ cases during 2008–2014 and HZ-associated deaths during1996–2012 in the entire population of Norway. We calculated HZ incidences for primary and hospital care by age, sex, type of health encounter, vaccination status, and co-morbidities among hospital patients. We also estimated HZ-associated mortality and case-fatality.ResultsThe study included 82,064 HZ patients, of whom none were reported as vaccinated against HZ. The crude annual incidence of HZ was 227.1 cases per 100,000 in primary healthcare and 24.8 cases per 100,000 in hospitals. Incidence rates were higher in adults aged ≥50 years (461 per 100,000 in primary care and 57 per 100,000 in hospitals), and women than in men both in primary healthcare (267 vs 188 per 100,000), and hospitals (28 vs 22 per 100,000). Among hospital patients, 47% had complicated zoster and 25% had comorbidities, according to the Charlson comorbidity index. The duration of hospital stay (median 4 days) increased with the severity of comorbidities. The estimated mortality rate was 0.18 per 100,000; and in-hospital case-fatality rate was 1.04%.ConclusionsMedically attended HZ poses a substantial burden in the Norwegian healthcare sector. The majority of the zoster cases occurred among adults aged ≥50 years – the group eligible for zoster vaccination – and increased use of zoster vaccination may be warranted, especially among persons with co-morbidities.     

BCG vaccine: WHO position paper,February 2018 – Recommendations

This article presented the World Health Organization’s (WHO) recommendations on the use of on Bacille Calmette-Guérin (BCG) vaccine excerpted from the BCG vaccines: WHO position paper – February 2018 published in the Weekly Epidemiological Record [1]. This position paper replaces the 2004 WHO position paper on Bacille Calmette-Guérin (BCG) vaccine [2] and the 2007 WHO revised BCG vaccination guidelines for infants at risk for human immunodeficiency virus (HIV) infection [3]. It incorporates recent developments in the tuberculosis (TB) field, provides revised guidance on the immunization of children infected with HIV, and re-emphasizes the importance of the birth dose. This position paper also includes recommendations for the prevention of leprosy.Footnotes to this paper provide a number of core references including references to grading tables that assess the quality of the scientific evidence, and to the evidence-to-recommendation tables. In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale immunization programmes; they summarize essential background information on diseases and vaccines, and conclude with WHO’s current position on the use of vaccines in the global context. Recommendations on the use of cholera vaccines were discussed by the Strategic Advisory Group of Experts (SAGE) in October 2017; evidence presented at these meetings can be accessed at: http://www.who.int/immunization/sage/meetings/2017/october/presentations_background_docs/en/     

The 2015–2016 influenza epidemic in Beijing,China: Unlike elsewhere,circulation of influenza A(H3N2) with moderate vaccine effectiveness

BackgroundWhile the 2015–2016 influenza season in the northern hemisphere was dominated by A(H1N1)pdm09 and B/Victoria viruses, in Beijing, China, there was also significant circulation of influenza A(H3N2) virus. In this report we estimate vaccine effectiveness (VE) against influenza A(H3N2) and other circulating viruses, and describe further characteristics of the 2015–2016 influenza season in Beijing.MethodsWe estimated VE of the 2015–2016 trivalent inactivated vaccine (TIV) against laboratory-confirmed influenza virus infection using the test-negative study design. The effect of prior vaccination on current VE was also examined.ResultsOf 11,000 eligible patients included in the study, 2969 (27.0%) were influenza positive. Vaccination coverage was 4.2% in both cases and controls. Adjusted VE against all influenza was 8% (95% CI: −16% to 27%): 18% (95% CI: −38% to 52%) for influenza A(H1N1)pdm09, 54% (95% CI: 16% to 74%) for influenza A(H3N2), and −8% (95% CI: −40% to 18%) for influenza B/Victoria. The overall VE for receipt of 2015–2016 vaccination only, 2014–2015 vaccination only, and vaccinations in both seasons was −15% (95% CI: −63% to 19%), −25% (95% CI: −78% to 13%), and 18% (95% CI: −11% to 40%), respectively.ConclusionsOverall the 2015–2016 TIV was protective against influenza infection in Beijing, with higher VE against the A(H3N2) viruses compared to A(H1N1)pdm09 and B viruses.     

Nephrotic syndrome following four-component meningococcal B vaccination: Epidemiologic investigation of a surveillance signal

BackgroundIn May 2014, a mass vaccination campaign with four-component meningococcal serogroup B (4CMenB) vaccine was launched in a localized region of Quebec, Canada experiencing high invasive meningococcal B disease endemicity. Active post-marketing surveillance identified several cases of nephrotic syndrome (NS) among ∼49,000 vaccinated individuals aged 2 months to 20 years. We report the epidemiologic investigation of this potential vaccine safety signal.MethodsActive vaccine safety surveillance was conducted electronically, with participants completing an online questionnaire prompted at 7 days after each dose and 6 months following the last dose. Additional NS cases were sought from provincial hospitalization and emergency room databases.ResultsIn the year following the first dose of 4CMenB vaccination, four confirmed NS cases (three hospitalized) were identified among vaccinated children 2–5-years-old with onset several months post-vaccination. None had renal biopsy but given their age, and positive response to steroids, idiopathic NS was presumptively diagnosed. Among vaccinated children 1–9-years-old, the NS incidence in the year post-vaccination was 17.7 per 100,000 (1 per 5650 vaccinees) with an NS hospitalization rate (i.e. excluding the outpatient case) that was 3.6-fold higher (95%CI = 0.7–11.8; p = 0.12) than the rest of the province for the same period, and 8.3-fold greater (95%CI = 1.1–62.0; p = 0.039) than during the eight years preceding the immunization campaign in the affected region.ConclusionActive safety surveillance identified an unexpected increase in NS incidence following 4CMenB vaccination. Further epidemiological investigation identified four vaccinated cases in total over a 12 month period of follow up. The greater risk in vaccinees had wide confidence intervals with he lower limit including or just above the nul value, an observation with no or marginal statistical significance. The temporal association with vaccination may be explained by other causes and/or chance clustering of a rare event unrelated to vaccination. To confirm or refute a potential link to vaccination, surveillance in other jurisdictions administering 4CMenB to children 1–9-years-old is needed.     

A big pertussis outbreak in a primary school with high vaccination coverage in northern China: An evidence of the emerging of the disease in China

BackgroundA big pertussis outbreak occurred in a primary school with high vaccination coverage in northern China. An investigation was carried out in order to calculate the attack rate and identify the risk factors.MethodsBetween May 12 and July 29, an investigation was carried out in the primary school, which included 383 students and 27 teachers. Three definitions were used to distinguish the cases: confirmed, epidemiologically linked and suspected cases. A total of 232 blood samples were collected and examined by ELISA among healthy children in another primary school.ResultsA total of 138 suspected pertussis cases were counted, of which 116 students were confirmed. The attack rate among students was as high as 30.29%. The pertussis outbreak lasted 88 days, and had quaternary cases of transmission. Migrant children were almost four times as likely to catch the disease as local children (p = 0.005). In addition, students who had received the last dose of pertussis vaccine more than 4 years prior were three times more likely of becoming ill than those less than 4 years (p = 0.006). The average level of antibodies to pertussis was 30.99 IU/mL among healthy children. No statistically significant difference was observed between DTaP and DTwP (p = 0.843).ConclusionsThis pertussis outbreak in a primary school with high vaccination coverage was an evidence of the pertussis resurgence in China. The major risk factor we identified was the waning of immunity in the years after pertussis vaccination. Booster vaccination for students should be given.     

Defining a correlate of protection for chikungunya virus vaccines

Chikungunya virus infection causes a debilitating febrile illness that in many affected individuals is associated with long-term sequelae that can persist for months or years. Over the past decade a large number of candidate vaccines have been developed, several of which have now entered clinical trials. The rapid and sporadic nature of chikungunya outbreaks poses challenges for planning of large clinical efficacy trials suggesting that licensure of chikungunya vaccines may utilize non-traditional approval pathways based on identification of immunological endpoint(s) predictive of clinical benefit. This report reviews the current status of nonclinical and clinical testing and potential challenges for defining a suitable surrogate or correlate of protection.     

Analysis of the profitability of adult vaccination in 13 private provider practices in the United States

Vaccination coverage among adults remains low in the United States. Understanding the barriers to provision of adult vaccination is an important step to increasing vaccination coverage and improving public health. To better understand financial factors that may affect practice decisions about adult vaccination, this study sought to understand how costs compared with payments for adult vaccinations in a sample of U.S. physician practices. We recruited a convenience sample of 19 practices in nine states in 2017. We conducted a time-motion study to assess the time costs of vaccination activities and conducted a survey of practice managers to assess materials, management, and dose costs and payments for vaccination. We received complete cost and payment data from 13 of the 19 practices. We calculated annual income from vaccination services by comparing estimated costs with payments received for vaccine doses and vaccine administration. Median annual total income from vaccination services was $90,343 at family medicine practices (range: $3968–$249,628), $28,267 at internal medicine practices (−$32,659–$141,034) and $2886 at obstetrics and gynecology practices (−$73,451–$23,820). Adult vaccination was profitable at the median of our sample, but there is wide variation in profitability due to differences in costs and payment rates across practices. This study provides evidence on the financial viability of adult vaccination and supports actions for improving financial viability. These results can help inform practices’ decisions whether to provide adult vaccines and contribute to keeping adults up-to-date with the recommended vaccination schedule.     

Vaccination of healthcare personnel in Europe: Update to current policies

We investigated and compared current national vaccination policies for health-care personnel (HCP) in Europe with results from our previous survey. Data from 36 European countries were collected using the same methodology as in 2011. National policies for HCP immunization were in place in all countries. There were significant differences in terms of number of vaccinations, target HCP and healthcare settings, and implementation regulations (recommended or mandatory vaccinations). Vaccination policies against hepatitis B and seasonal influenza were present in 35 countries each. Policies for vaccination of HCP against measles, mumps, rubella and varicella existed in 28, 24, 25 and 19 countries, respectively; and against tetanus, diphtheria, pertussis and poliomyelitis in 21, 20, 19, and 18 countries, respectively. Recommendations for hepatitis A immunization existed in 17 countries, and against meningococcus B, meningococcus C, meningococcus A, C, W, Y, and tuberculosis in 10, 8, 17, and 7 countries, respectively. Mandatory vaccination policies were found in 13 countries and were a pre-requisite for employment in ten. Comparing the vaccination programs of the 30 European countries that participated in the 2011 survey, we found that more countries had national vaccination policies against measles, mumps, rubella, hepatitis A, diphtheria, tetanus, poliomyelitis, pertussis, meningococcus C and/or meningococcus A, C, W, Y; and more of these implemented mandatory vaccination policies for HCP. In conclusion, European countries now have more comprehensive national vaccination programs for HCP, however there are still gaps. Given the recent large outbreaks of vaccine-preventable diseases in Europe and the occupational risk for HCP, vaccination policies need to be expanded and strengthened in several European countries. Overall, vaccination policies for HCP in Europe should be periodically re-evaluated in order to provide optimal protection against vaccine-preventable diseases and infection control within healthcare facilities for HCP and patients.