Prevention of hepatitis B mother-to-child transmission in Namibia: A cost-effectiveness analysis

Despite access to a safe and effective vaccine, mother-to-child transmission (MTCT) of hepatitis B virus (HBV) persists in Africa. This is of concern since perinatally-infected infants are at highest risk of developing hepatocellular carcinoma, a life-threatening consequence of chronic HBV infection. While tools to prevent HBV MTCT are available, the cost implications of these interventions need consideration prior to implementation. A Markov model was developed to determine the costs and health outcomes of (1) universal HBV birth dose (BD) vaccination, (2) universal BD vaccination and targeted hepatitis B immunoglobulin (HBIG), (3) maternal antiviral prophylaxis using sequential HBV viral load testing added to HBV BD vaccination and HBIG, and (4) maternal antiviral prophylaxis using sequential HBeAg testing combined with HBV BD vaccination and HBIG. Health outcomes were assessed as the number of paediatric infections averted and disability-adjusted life years (DALYs) averted. Primary cost data included consumables, human resources, and hospital facilities. HBV epidemiology, transitions probabilities, disability weights, and the risks of HBV MTCT were extracted from the literature. Incremental cost-effectiveness ratios (ICERs) were calculated to compare successive more expensive interventions to the previous less expensive one. One-way sensitivity analyses were conducted to test the robustness of the model’s outputs. At the Namibian cost/DALY averted threshold of US$3 142, the (1) BD vaccination + targeted HBIG, and (2) maternal antiviral prophylaxis with sequential HBeAg testing interventions were cost-effective. These interventions had ICERs equal to US$1909.03/DALY and US$2598.90/DALY averted, respectively. In terms of effectiveness, the maternal antiviral prophylaxis with sequential HBeAg testing intervention was the intervention of choice. The analysis showed that elimination of HBV MTCT is achievable using maternal antiviral prophylaxis with active and passive immunization. There is an urgent need for low cost diagnostic tests to identify those women who will most benefit from drug therapy to attain this laudable goal.     

Understanding what people think and feel about adult vaccinations and the associated barriers in Greece: Development and validation of the attitude towards adult vaccination (ATAVAC) scale

Despite the unequivocal value of vaccination in reducing the global burden of infectious diseases, the anti-vaccination movement thrives. The vast majority of the existing validated tools explore attitudes regarding vaccination in children. The aim of our study was to develop and validate a scale assessing attitudes towards adult immunisation. This national cross-sectional study included adult healthcare users who visited 23 Greek Primary Healthcare Units. The development of the scale was the result of literature review, semi-structured interviews and pilot testing of its preliminary versions. The initial version contained 15 items measuring respondents’ attitudes on a 6-point Likert scale. The sample was randomly split into two halves. Exploratory factor analysis, performed in the first sample, was used for the creation of multi-item scales; confirmatory factor analysis was used in the second sample to assess goodness of fit. Moreover, concurrent validity, internal consistency reliability, test–retest reliability and ceiling and floor effects were explored. The total sample consisted of 1,571 individuals. Overall ‘Cronbach's alpha’ (0.821) indicated good internal consistency. The initial exploratory factor analysis resulted in a three-factor model. The subsequent confirmatory factor analysis indicated that an 11-item version of the scale provided the best fit of the model to the data (RMSEA = 0.050, SRMR = 0.053, TLI = 0.937, CFI = 0.955, AIC = 24,999.949). All subscales (‘value of adult vaccination’, ‘safety concerns’ and ‘perceived barriers’) demonstrated strong concurrent associations with participants’ attitudes and behaviour regarding vaccination (p < .001). No ceiling or floor effects were noted for any of the subscales (0.13%, 2.61% and 0.51%; 0.13%, 0.57% and 0.45% respectively). The 11-item ATAVAC scale proved to be a reliable and valid tool, suitable for assessing attitudes towards adult vaccination.     

Can what have we learnt about BCG vaccination in the last 20 years help us to design a better tuberculosis vaccine?

The BCG vaccine will, in 2021, have been in use for 100 years. Much remains to be understood, including the reasons for its variable efficacy against pulmonary tuberculosis in adults. This review will discuss what has been learnt about the BCG vaccine in the last two decades, and whether this new information can be exploited to improve its efficacy, by enhancing its ability to induce either antigen-specific and/or non-specific effects. Many factors affect both the immunogenicity of BCG and its protective efficacy, highlighting the challenges of working with a live vaccine in man, but new insights may enable us to exploit better what BCG can do.     

COVID-19 vaccination in pregnant women in Sweden and Norway

Vaccines against SARS-CoV-2 are highly effective in preventing severe disease and mortality. Although pregnant women are at increased risk of severe COVID-19, vaccination uptake among pregnant women varies. We used the Swedish and Norwegian population-based health registries to identify pregnant women and to investigate background characteristics associated with not being vaccinated. In this study of 164 560 women giving birth between May 2021 and May 2022, 78% in Sweden and 87% in Norway have been vaccinated with at least one dose at delivery. Not being vaccinated while being pregnant was associated with age below 30 years, low education and income level, birth region other than Scandinavia, smoking during pregnancy, not living with a partner, and gestational diabetes. These results can assist health authorities develop targeted vaccination information to diminish vaccination inequality and prevent severe disease in vulnerable groups.     

Factors associated with repeated influenza vaccine uptake among aged care staff in an Australian sample from 2017 to 2019

Background/AimInfluenza vaccination is strongly recommended every year for aged care staff to protect themselves and minimise risk of transmission to residents. This study aimed to determine the factors associated with repeated annual influenza vaccine uptake among Australian aged care staff from 2017 to 2019.MethodsDemographic, medical and vaccination data collected from the staff, who participated in an observational study from nine aged care facilities under a single provider in Sydney Australia, were analysed retrospectively. Based on the pattern of repeated influenza vaccination from 2017 to 2019, three groups were identified: (1) unvaccinated all three years; (2) vaccinated occasionally(once or twice) over three years; and (3)vaccinated all three years. Multinomial logistic regression analysis was performed to better understand the factors associated with the pattern of repeated influenza vaccination.ResultsFrom a total of 138 staff, between 2017 and 2019, 28.9 % (n = 40) never had a vaccination, while 44.2 % (n = 61) had vaccination occasionally and 26.8 % (n = 37) had vaccination all three years. In the multinomial logistic regression model, those who were<40 years old (OR = 0.57, 95 % CI: 0.19–0.90, p < 0.05) and those who were current smokers (OR = 0.20; 95 % CI: 0.03–0.76, p < 0.05) were less likely to have repeated vaccination for all three years compared to the unvaccinated group. Those who were<40 years old (OR = 0.61; 95 % CI: 0.22–0.68, p < 0.05) and those who were born overseas (OR = 0.50; 95 % CI:0.27–0.69, p < 0.05) were more likely to be vaccinated occasionally compared to the unvaccinated group.ConclusionThe significant predictors of repeated vaccine uptake across the three-year study period among aged care staff were age, smoking status and country of birth (Other vs Australia). Targeted interventions towards the younger age group (<40 years old), smokers and those who were born overseas could improve repeated influenza vaccination uptake in the aged care workforce.     

Mendelian randomization suggests a potential causal effect of eosinophil count on influenza vaccination responsiveness

Currently, the clinical factors affecting immune responses to influenza vaccines have not been systematically explored. The mechanism of low responsiveness to influenza vaccination (LRIV) is complicated and not thoroughly elucidated. Thus, we integrate our in-house genome-wide association studies (GWAS) analysis result of LRIV (N = 111, Ncase [Low Responders] = 34, Ncontrol [Responders] = 77) with the GWAS summary of 10 blood-based biomarkers (sample size ranging from 62 076−108 794) deposited in BioBank Japan (BBJ) to comprehensively explore the shared genetics between LRIV and blood-based biomarkers to investigate the causal relationships between blood-based biomarkers and LRIV by Mendelian randomization (MR). The applications of four MR approaches (inverse-variance-weighted [IVW], weighted median, weighted mode, and generalized summary-data-based MR [GSMR]) suggested that the genetically instrumented LRIV was associated with decreased eosinophil count (β = −5.517 to −4.422, p = 0.004−0.039). Finally, we conclude that the low level of eosinophil count is a suggestive risk factor for LRIV.     

Association of sleep duration and quality with immunological response after vaccination against severe acute respiratory syndrome coronavirus-2 infection

Growing evidence suggests that sleep could affect the immunological response after vaccination. The aim of this prospective study was to investigate possible associations between regular sleep disruption and immunity response after vaccination against coronavirus disease 2019 (COVID-19). In total, 592 healthcare workers, with no previous history of COVID-19, from eight major Greek hospitals were enrolled in this study. All subjects underwent two Pfizer–BioNTech messenger ribonucleic acid (mRNA) COVID-19 vaccine BNT162b2 inoculations with an interval of 21 days between the doses. Furthermore, a questionnaire was completed 2 days after each vaccination and clinical characteristics, demographics, sleep duration, and habits were recorded. Blood samples were collected and anti-spike immunoglobulin G antibodies were measured at 20 ± 1 days after the first dose and 21 ± 2 days after the second dose. A total of 544 subjects (30% males), with median (interquartile range [IQR]) age of 46 (38–54) years and body mass index of 24·84 (22.6–28.51) kg/m² were eligible for the study. The median (IQR) habitual duration of sleep was 6 (6–7) h/night. In all, 283 participants (52%) had a short daytime nap. In 214 (39.3%) participants the Pittsburgh Sleep Quality Index score was >5, with a higher percentage in women (74·3%, p < 0.05). Antibody levels were associated with age (r = −0.178, p < 0.001), poor sleep quality (r = −0.094, p < 0.05), insomnia (r = −0.098, p < 0.05), and nap frequency per week (r = −0.098, p < 0.05), but after adjusting for confounders, only insomnia, gender, and age were independent determinants of antibody levels. It is important to emphasise that insomnia is associated with lower antibody levels against COVID-19 after vaccination.     

The BCG controversy

The history of tuberculosis control by vaccination with Bacille Calmette-Guérin (BCG) is reviewed. Use of the vaccine is evaluated in light of conflicting results from trials of BCG efficacy. Explanatinations are suggested for the variations between trials, and the continued use of BCG as a vaccine against tuberculosis is discussed.     

Perspectives on rapid elimination and ultimate global eradication of paralytic poliomyelitis caused by polioviruses

Poliomyelitis caused by polioviruses has already been eradicated from industrialized countries of North America, Europe, Asia and Oceania, but the procedures by which this eradication was achieved are not adequate for the poor tropical and subtropical countries. The major challenge now is first to eliminate it rapidly from Asia and Africa where an estimated 250,000 cases and 25,000 deaths currently occur annually. The great progress toward eradication of wild polioviruses from poor tropical and subtropical countries in Latin America was achieved not by the procedures still recommended by the WHO Expanded Program on Immunization (EPI) but by the independently organized annual, national days of antipolio vaccination — all based on the use of large armies of well-trained non-professional, community volunteers — first used in Cuba (1962), Brazil (1980), Nicaragua (1981), Dominican Republic (1983), Paraguay (1985), and Mexico (1986). This novel approach, described in some detail in this communication, is recommended for the rapid elimination of wild polioviruses from Asia and Africa, and for ultimate global eradication with the help of a special cadre within the EPI of WHO. The extensive use by the Pan American Health Organization (PAHO) of highly sophisticated regional virus laboratories has led to the recognition that, in areas from which poliomyelitis caused by polioviruses has been largely eliminated, there are thousands of cases of acute flaccid paralysis, previously clinically diagnosed as probable poliomyelitis, that have no viral etiology, a phenomenon previously reported by Dr. Manuel Ramos Alvarez in Mexico City in 1967.     

Effect of active immunization to luteinizing-hormone-releasing hormone on the fertility and histoarchitecture of the reproductive organs of male rat

Summary The feasibility of using a vaccine against luteinizing-hormone-releasing factor for supression of pituitary and gonadal functions has been indicated for some time. Antibody production against this low-molecular-weight, naturally occurring decapeptide, however, requires to be coupled to a carrier protein to enhance its immunogenicity. LHRH was coupled to diphtheria toxoid (DT). Adult male Sprague-Dawley rats with a mean basal body weight of 200g were immunized with anti-LHRH-DT (20 g/injection/rat) at four-week intervals. An equal number of unexposed animals served as controls. Six animals were killed every two weeks up the end of the week 43. The vaccination schedule did not have any effect on the gain in body weight, nor was any adverse effect of vaccination observed in the course of the investigations. The pituitary, prostate, epididymis, testes, seminal vesicles, adrenal and thyroid were excised for determination of organ weight and histological examination. The adrenal, pituitary and thyroid showed no remarkable weight changes during the observation period, whereas the weights of the reproductive organs demonstrated significant reductions compared to those of the control group. The histopathology revealed marked to significant changes in the gonads and the accessory sex organs including the prostate. A progressive phase of regeneration of spermatogenesis was evident 98 days after vaccination. Total recovery of spermatogenesis was observed 300 days after vaccination. The mating studies showed the return of fertility 300 days after vaccination. The litters borne were normal. Prostate showed recovery after 154 days of vaccination. Our observations lend strong support to the hypothesis that anti-LHRH vaccine can be effectively used on the management of prostate carcinoma. If the vaccination is given together with a suitable dose of long-acting androgen, contained in an adequate delivery system, the regimen may be used for the regulation of male fertility.