Comparison of antibody response between boys and girls after infant and childhood vaccinations in the Netherlands

12-month SARS-CoV-2 antibody persistency in a Tyrolean COVID-19 cohort

Background

Short-term antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been shown previously. The further development remains to be determined.

Methods

We prospectively followed 29 coronavirus disease 2019 cases, mean age 44 ± 13.2 years. Except for one participant in whom rheumatoid arthritis existed, all other cases were previously healthy. We determined anti-viral binding antibodies at 2–10 weeks, 3 months, 6 months, and 12 months after disease onset as well as neutralizing antibodies (NAb) against wild type at 6 and 12 months and the B.1.1.7 and B.1.351 variants at month 12. Three binding antibody assays were used, targeting the nucleocapsid protein (NCP), the S1 subunit of the spike protein, and the receptor binding domain (RBD).

Results

Antibodies to the RBD persisted for 12 months in all cases with increasing concentrations, whereas antibodies to S1 dropped below cut-off point in 7 participants and NCP antibodies were above cut-off point in only 5 subjects at month 12. The NAb against wild type were detected in all but 2 samples at 12 months of follow-up but clearly less frequently when targeting the variants. In 5 participants who were vaccinated against COVID-19 there was a strong increase of antibodies against S1 and RBD as well as an increase of NAb titres against wild type and the variants.

Conclusion

There was a persisting antibody response against SARS-CoV‑2 up to 12 months after COVID-19 with declining concentrations except for RBD and a strong increase of all antibody concentrations after vaccination.

Supplementary Information

The online version of this article (10.1007/s00508-021-01985-x) contains supplementary material, which is available to authorized users.

Rubella Serosurvey Among Future Healthcare Workers

Objective: Rubella is a very diffusive but relatively benign infectious disease unless contracted during pregnancy, when it causes congenital rubella syndrome. The aim of this research was to determine the prevalence and titer of antirubella antibodies in a population of future healthcare workers (students at the school of medicine). Methods: The cohort consisted of 11,022 students who underwent antibody analysis after the presentation of a vaccine certificate. Results: Vaccination compliance was very high, particularly in younger students (born after 1995), reaching almost 100% (at least one dose). Unvaccinated students born before 1990 had high seropositivity (>95%), but this percentage dropped to zero among the youngest students. Variables affecting antibody titer included year of birth and sex. Considering only vaccinated students, a greater antibody response was observed if the vaccine was administered between 8 and 10 years of age. Female sex was associated with more significant (p < 0.0001) positivity and higher antibody titer after one and two doses. However, this difference appeared less consistent in relation to year of birth. Conclusions: The studied population exhibited excellent vaccination compliance, high seropositivity, and high antibody titer. Vaccine and immune coverage were higher than what is deemed necessary to achieve herd immunity.

Response to Vaccination against Mumps in Medical Students: Two Doses Are Needed

Mumps is a vaccine-preventable infectious disease diffuse worldwide. The implementation of mumps vaccination reduced largely the spread of infection. On 11,327 Medical School students the prevalence of mumps positive antibodies was evaluated according to dose/doses of vaccine, year of birth and sex. Compliance to mumps vaccine was low in students born before 1990 but increased consistently after this year, above all compliance to two doses, due to the implementation of the vaccine offer. Positivity of mumps antibodies is significantly (p < 0.0001) lower in students vaccinated once (71.2%) compared to those vaccinated twice (85.4%). In addition, students born after 1995, largely vaccinated twice, showed a seropositivity near to 90%. Further, females had a significantly (p < 0.0001) higher proportion of positive antibodies after vaccination than males, both one (74.6% vs. 64.7%) and two doses (86.8% vs. 82.9%). Finally, seropositivity after two vaccine doses remains high (86.1%) even 15 years after the second dose. In conclusion, the research highlighted that vaccination against mumps reaches a good level of coverage only after two doses of vaccine persisting at high levels over 15 years and induces a more significant response in females.

A meta-analytic evaluation of sex differences in meningococcal disease incidence rates in 10 countries

The magnitude and consistency of the sex differences in meningococcal disease incidence rates (IR) have not been systematically examined in different age groups, countries and time periods. We obtained national data on meningococcal disease IR by sex, age group and time period, from 10 countries. We used meta-analytic methods to combine the male to female incidence rate ratios (IRRs) by country and year for each age group. Meta-regression analysis was used to assess the contribution of age, country and time period to the variation in the IRRs. The pooled male to female IRRs (with 95% CI) for ages 0–1, 1–4, 5–9, 10–14 and 15–44, were 1.25 (1.19–1.32), 1.24 (1.20–1.29), 1.13 (1.07–1.20), 1.21 (1.13–1.29) and 1.15 (1.10–1.21), respectively. In the age groups 45−64 and over 65, the IR were lower in males with IRRs of 0.83 (0.78–0.88) and 0.64 (0.60–0.69), respectively. Sensitivity analysis and meta-regression confirmed that the results were robust. The excess meningococcal IR in young males and the higher rates in females at older ages were consistent in all countries, except the Czech Republic. While behavioural factors could explain some of the sex differences in the older age groups, the excess rates in very young males suggest that genetic and hormonal differences could be important.

Is there an association between socioeconomic status and immune response to infant and childhood vaccination in the Netherlands?

INTRODUCTION

Socioeconomic status (SES) is a well-known determinant of health, but its relation with vaccine-induced immunity is less documented. We explored the association between SES and immunoglobulin G (IgG) levels against vaccine-preventable diseases in vaccinated children in the Dutch National Immunization Programme.

METHODS

Data from a population-wide cross-sectional serosurvey in the Netherlands (2006-2007) were used. We compared geometric mean IgG concentrations/titers (GMC/T ratios) against measles, mumps, rubella, Haemophilus influenzae type b (Hib), Neisseria meningococcus type C, diphtheria, tetanus, poliovirus types 1,2,3 and pertussis in children of high versus low SES by linear regression analysis. We included 894 children (0-12 years) at one of two timeframes: 1 month to 1 year, or 1-3 years after vaccination. Mother's educational level and net household income served as binary indicators of SES.

RESULTS

Of 58 possible associations of vaccine-induced antibody responses with educational level and 58 with income, 10 (9%) were statistically significant: 2 favouring (that is, with higher IgG levels at) high educational level (for Hib 1 m-1y after vaccination (GMC/T ratio: 2.99, 95%CI: 1.42-6.30) and polio 2 1 m-1y after the 9-year booster dose (1.14, 1.01-1.27)) and 8 favouring low income (polio 1, 2 and 3 1 m-1y after the 11-month booster (0.74, 0.58-0.94; 0.79, 0.64-0.97; 0.72, 0.55-0.95), polio 3 and pertussis 1-3y after the 11-month booster (0.70, 0.56-0.88; pertussis-prn: 0.60, 0.37-0.98; pertussis-ptx: 0.66, 0.47-0.95), mumps and rubella 1-3y after first vaccination (0.73, 0.55-0.97; 0.70, 0.55-0.90), and rubella 1 m-1y after second vaccination (0.83, 0.55-0.90)). After adjustment for multiple testing, none of the differences remained significant. There was no association between SES and proportion of children with protective IgG levels.

CONCLUSION

In this explorative study, we found no consistent association between SES and immune response to vaccination in the Netherlands and no association with protective IgG levels. Additional studies in other settings should confirm this finding.

The relationship between meteorological factors and mumps based on Boosted regression tree model

BACKGROUND

Mumps remains a major global public health problem. Many studies have explored the relationship between meteorological factors and mumps, few have comprehensively explored such associations considering nonlinear relationship, delayed effects and collinearity in order to more accurately estimate them. This study aims to explore the relationship between meteorological factors and mumps in consideration of nonlinearity, delayed effects and collinearity.

METHODS

We collected daily reported mumps cases and meteorological data for Jining City, Shandong Province, China from 1 January 2007 to 31 December 2016. By building a Boosted regression tree model (BRT) for each day from lag 0days to the maximum lag time, the optimal lag time was selected and the relationship between meteorological factors and mumps was explored for this lag time.

RESULTS

From 2007 to 2016, a total of 15,064 cases of mumps were reported in Jining, with a sex ratio of 2.11:1. Cases were most prevalent in 5-9-year-olds (42.15%) followed by 10-14-year-olds (24.72%). The optimal lag time identified was 10days and the three meteorological factors that contributed the most to the risk of mumps were daily mean temperature, daily mean relative humidity and daily mean sunshine duration. Their relative contribution rates were 24.4%, 19.9% and 18.3%, respectively. The mean temperature and sunshine duration relationships approximated a U-shaped effect on the risk of mumps, with estimated thresholds of 5.5°C and 9.5h, respectively. The effect of relative humidity on mumps increased slightly and then decreased rapidly, with a threshold of 64%.

CONCLUSIONS

Our study indicates that daily mean temperature, relative humidity and sunshine duration were three significant meteorological factors associated with the incidence of mumps in Jining, China. Understanding the shape of relationships and their thresholds are critical for establishing early warning systems which are important tools in the prevention and control of mumps.

Measles Virus Infection and Immunity in a Suboptimal Vaccination Coverage Setting

Despite efforts to improve surveillance and vaccination coverage, measles virus (MeV) continues to cause outbreaks also in high-income countries. As the reference laboratory of the Veneto Region, Italy, we analyzed changes in population immunity, described measles outbreaks, investigated MeV genetic diversity, and evaluated cross-protection of measles vaccination against MeV epidemic strains. Like most European areas, the Veneto Region has suboptimal measles vaccination coverage and is facing a growing public mistrust of vaccination. A progressive decline of measles vaccine uptake was observed during the last decade in the Veneto Region, leading to immunity gaps in children and young adults. Measles outbreaks were caused by the same MeV genotype B3, D4, and D8 strains that were circulating in other European countries. Eleven cases of measles were observed in immunized subjects. These cases were not associated with particular MeV genotypes nor with mutations in epitopes recognized by neutralizing antibodies. Accordingly, sera from fully vaccinated subjects cross-neutralized epidemic MeV strains, including the genotypes B3, D4, and D8, with the same high efficiency demonstrated against the vaccine strain. In fully vaccinated subjects, high MeV IgG antibody titers persisted up to 30 years following vaccination. These results support the use of the current measles-containing vaccines and strategies to strengthen vaccination.

Measles Elimination: Identifying Susceptible Sub-Populations to Tailor Immunization Strategies

Measles elimination has been identified as a public health priority in Europe for a long time but has not yet been achieved. The World Health Organization (WHO) recommends identification of susceptible sub-populations to target supplementary immunization activities. We used three different sources of information: retrospective samples investigated for measles IgG between 1997 and 2016, vaccine coverage data from the existing electronic registry for birth cohorts 2015 to 1999, and surveillance data from 2009 until 20 July 2019. We calculated susceptibility by birth cohort using seroprevalence data, adjusting vaccine coverage data with reported effectiveness (93% for the first and 97% for the second dose, respectively), and compared it with measles incidence data, aggregated by birth cohorts and districts. Susceptibility levels for persons 10–41 years (birth cohorts 2007–1976) were 10.4% and thus far above the recommended values of WHO (5%). Older birth cohorts were sufficiently protected. Districts with the highest susceptibility estimates corresponded with districts with the highest incidence rates. Birth cohorts with susceptibility levels > 10% showed a 4.7 increased relative risk of having had more than one measles case. We conclude that retrospective serosurveys are a cheap and useful approach in identifying susceptible sub-populations, especially for older birth cohorts whose coverage data remain scarce.