Measles Immunity at 4.5 Years of Age Following Vaccination at 9 and 15-18 Months of Age Among Human Immunodeficiency Virus (HIV)-infected, HIV-exposed-uninfected, and HIV-unexposed Children

High risk of low birth weight in couples with advanced paternal age in in vitro fertilization treatment

BACKGROUND

With the development of socio-economic conditions and a shift in attitudes towards fertility, there has been a gradual increase in delayed childbearing since the 2000s. Age plays a significant role in the decline of fertility. However, we know very little about the association of paternal age with reproductive outcomes.

OBJECTIVES

To investigate the correlation between advanced paternal age and semen quality, embryo quality, pregnancy, and neonatal outcomes in IVF cycles.

MATERIALS AND METHODS

In this study, after excluding female partners aged ≥35 years, we analyzed data from 761 infertile couples who underwent in vitro fertilization cycles at the First Affiliated Hospital of USTC between June 2020 and March 2023. Cases were classified into three groups according to the age of the male: <35 years (530 infertile couples), 35 years ≤ paternal age <40 years (125 infertile couples), and ≥40 years (106 infertile couples). Then, we compared the general clinical data arising from in vitro fertilization cycles between the three groups, including semen parameters, embryonic parameters, and pregnancy and neonatal birth outcomes.

RESULTS

Data analysis showed that the duration of infertility and the incidence of secondary infertility were significantly higher in paternal age ≥35 years groups than those aged <35 years (all p < 0.05). We also observed a significant difference between ≥40 years and <35 years groups in terms of the normal fertilization rate, high-quality embryo rate, clinical pregnancy rate, miscarriage rate, live birth rate, Apgar scores, and the low birth weight neonatal rate (all p < 0.05). The group with paternal age ≥40 years showed statistically significant differences in terms of clinical pregnancy rate, miscarriage rate, live birth rate, and low birth weight on multivariable logistic regression (all p < 0.05).

CONCLUSION

The results of our study indicate that advanced paternal age (≥40 years) has a significant impact on the embryo quality, pregnancy outcome, and neonatal outcome. Paternal age over 40 years is a risk for in vitro fertilization success rate.

Single and two-dose typhoid conjugate vaccine safety and immunogenicity in HIV-exposed uninfected and HIV-unexposed uninfected Malawian children

Vaccine safety and immunogenicity data in human immunodeficiency virus (HIV)-exposed uninfected (HEU) children are important for decision-making in HIV and typhoid co-endemic countries. In an open-label study, we recruited Malawian HEU and HIV unexposed uninfected (HUU) infants aged 9 - 11 months. HEU participants were randomized to receive Vi-tetanus toxoid conjugate vaccine (Vi-TT) at 9 months, Vi-TT at 15 months, or Vi-TT at 9 and 15 months. HUU participants received Vi-TT at 9 and 15 months. Safety outcomes included solicited and unsolicited adverse events (AE) and serious AEs (SAEs) within 7 days, 28 days, and 6 months of vaccination, respectively. Serum was collected before and at day 28 after each vaccination to measure anti-Vi IgG antibodies by enzyme-linked immunosorbent assay (ELISA). Cohort 1 (66 participants) enrollment began 02 December 2019, and follow-up was terminated before completion due to the COVID-19 pandemic. Cohort 2 (100 participants) enrollment began 25 March 2020. Solicited AEs were mostly mild, with no significant differences between HEU and HUU participants or one- and two-dose groups. All six SAEs were unrelated to vaccination. Anti-Vi geometric mean titers (GMT) increased significantly from 4.1 to 4.6 ELISA units (EU)/mL at baseline to 2572.0 - 4117.6 EU/mL on day 28 post-vaccination, and similarly between HEU and HUU participants for both one- and two-dose schedules. All participants seroconverted (>4-fold increase in GMT) by the final study visit. Our findings of comparable safety and immunogenicity of Vi-TT in HUU and HEU children support country introductions with single-dose Vi-TT in HIV-endemic countries.

Seroprotection against measles in previously vaccinated children with difficult-to-treat nephrotic syndrome

BACKGROUND

Children with nephrotic syndrome (NS) are vulnerable to infections. Measles infection is an important cause of morbidity and mortality in immunosuppressed children. A suboptimal seroprotection against measles has been shown in immunocompromised children. There is limited published literature on measles immunity in children with difficult-to-treat nephrotic syndrome (DTNS). We compared the proportions of children with DTNS and healthy controls who were seroprotected against measles.

METHODS

This was a cross-sectional study. Measles-specific IgG antibodies of 108 children with DTNS (3 to 10 years of age) and an equal number of age-matched healthy controls were measured. All children had received two doses of measles-containing vaccine at 9-12 and 16-24 months of age under routine immunisation programme. Serum measles IgG antibody titres were measured by indirect ELISA. The assay results were interpreted as (1) > 11 NTU (NovaTec Units), positive/seroprotective titres; (2) 9-11, equivocal; and (3) < 9 NTU, negative. Inter- and intra-group comparisons were made to identify the disease characteristics related to seroprotection status.

RESULTS

The proportion of children with protective anti-measles antibodies (n = 70, 65%) was significantly lower in DTNS as compared to controls (n = 88, 81.48%) (p = 0.005). Their median [IQR] antibody titres were also significantly lower than those in controls (14.1 [14] NTU vs. 18.3 [15.2] NTU (p = 0.001). The age, gender, clinical subtype, duration of disease, and type of immunosuppressive therapy were not significantly different between seroprotected and non-seroprotected children with DTNS.

CONCLUSION

A significantly lower percentage of fully vaccinated children with DTNS were seroprotected against measles compared to healthy controls. A higher resolution version of the Graphical abstract is available as Supplementary information.

Measles vaccination of special risk groups

Measles is an important vaccine preventable disease with significant morbidity and mortality. Although measles vaccine is a safe and effective vaccine available worldwide for more than 50 years, still immunization efforts have not successfully reached the WHO goal of 95% vaccination coverage. Hesitancy is especially increased amongst parents of children with chronic conditions. Contraindications for measles-containing vaccines are well defined and include history of anaphylactic reactions to neomycin, history of severe allergic reaction to previous vaccination, pregnancy, and severe immunosuppression. Concurrently, precautions for measles-containing vaccines include amongst other, history of thrombocytopenia or thrombocytopenic purpura and personal or family history of seizures of any etiology. This article aims to address misconceptions on measles vaccine safety and review data on adverse events among special groups of subjects at increased risk following measles immunization.

Measles, mumps, rubella prevention: how can we do better?

INTRODUCTION

Measles, mumps, and rubella incidence decreased drastically following vaccination programs' implementation. However, measles and mumps' resurgence was recently reported, outbreaks still occur, and challenges remain to control these diseases.

AREAS COVERED

This qualitative narrative review provides an objective appraisal of the literature regarding current challenges in controlling measles, mumps, rubella infections, and interventions to address them.

EXPERT OPINION

While vaccines against measles, mumps, and rubella (including trivalent vaccines) are widely used and effective, challenges to control these diseases are mainly related to insufficient immunization coverage and changing vaccination needs owing to new global environment (e.g. traveling, migration, population density). By understanding disease transmission peculiarities by setting, initiatives are needed to optimize vaccination policies and increase vaccination coverage, which was further negatively impacted by COVID-19 pandemic. Also, awareness of the potential severity of infections and the role of vaccines should increase. Reminder systems, vaccination of disadvantaged, high-risk and difficult-to-reach populations, accessibility of vaccination, healthcare infrastructure, and vaccination services management should improve. Outbreak preparedness should be strengthened, including implementation of high-quality surveillance systems to monitor epidemiology. While the main focus should be on these public health initiatives to increase vaccination coverage, slightly more benefits could come from evolution of current vaccines.

Effect of HIV-exposure and timing of antiretroviral treatment initiation in children living with HIV on antibody persistence and memory responses to Haemophilus influenzae type b and pneumococcal polysaccharide-protein conjugate vaccines

BACKGROUND

We investigated the effect of in utero HIV-exposure, timing of antiretroviral treatment (ART) initiation, and ART interruption on memory responses and persistence of immunity induced by pneumococcal (PCV) and Haemophilus influenzae type b (HibCV) polysaccharide-protein conjugate vaccines.

METHODS

Children were enrolled (6-12 weeks of age), and vaccinated with a three-dose primary series of 7-valent PCV (PCV7) and HibCV at 6, 10 and 14 weeks of age. Study groups included infants infected with HIV perinatally with CD4+ ≥ 25% initiating ART following immunological or clinical deterioration (ART-Def), or immediately upon enrolment followed by interruption at 40 (ART-Immed/40w) or 96 weeks (ART-Immed/96w); and HIV-uninfected infants with (HEU), and without HIV (HIV-unexpsoed) exposure in utero. Within each group, children were randomized to receive either a booster dose of PCV7 or HibCV at 15 months of age. PCV serotype-specific and polyribosyl ribitol phosphate (PRP) IgG were measured pre-boost, two-weeks post-boost and at two-years of age. Opsonophagocytic activity (OPA) to serotypes 9V, 19F and 23F was measured post-booster dose.

RESULTS

Persistence of IgG to PCV vaccine-serotypes and anti-PRP was similar in all groups of children living with HIV (CLWH) compared to HIV-unexposed children. Anamnestic responses to PCV and HibCV were also similar in all three groups of CLWH compared to HIV-unexposed children. CLWH, however, tended to have lower functional antibody (OPA) titers than HIV-unexposed children after the PCV booster dose for some serotypes. Immunity to PCV and HibCV was similar between the ART-Immed/40w and ART-Immed-96w groups. There were no differences in IgG kinetics between HEU and HIV-unexposed children.

CONCLUSIONS

A three dose primary series, with or without PCV or HibCV booster doses in CLWH initiated on ART during infancy, would likely be similarly effective in preventing invasive bacterial disease as in HIV-unexposed children.