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Vaccines Feb 2024In the Americas, deaths by diseases avoidable with vaccines are a significant contributor to child mortality. An essential means of reducing this is through broad...
BACKGROUND
In the Americas, deaths by diseases avoidable with vaccines are a significant contributor to child mortality. An essential means of reducing this is through broad vaccine coverage. The COVID-19 pandemic has posed a potential disruption to vaccine coverage due to its effects on the healthcare system.
OBJECTIVES
this study aims to evaluate the impact of the COVID-19 pandemic on DTP3 vaccination coverage in the Americas, investigating trends from 2012 to 2022 to identify significant changes, regional disparities, and the overall effect of the pandemic on progress towards global immunization targets.
METHODS
This study used the coverage data for the third dose of the diphtheria, tetanus, and pertussis vaccine (DTP3) pulled from UNICEF databases spanning 2012 to 2022. We conducted a Joinpoint regression to identify points of significant trend changes. The annual percentage change (APC) and 95% confidence intervals (95% CIs) were calculated for America and its regions. We also used segmented regression analysis. Using the Chi-square test, we compared DTP3 vaccination coverage for each country between 2019 and 2022.
RESULTS
Overall, America saw a decrease in vaccine coverage during this period, with an APC of -1.4 (95% CI -1.8; -1.0). This trend varied across regions. In North America, the decrease was negligible (-0.1% APC). South America showed the steepest decrease, with an APC of -2.5%. Central America also declined, with an APC of -1.3%. Our findings suggest a concerning trend of declining DTP-vaccination rates in the Americas, exacerbated in certain regions, in the wake of the COVID-19 pandemic. The absolute decrease in vaccine coverage in the Americas was -4% between 2019 and 2022, with the most important drop being in Central America (-7%). However, six countries reported increased vaccination rates post-COVID-19, led by Brazil, with a 7% increase. Conversely, twenty-two countries registered a decline in DTP3 vaccine coverage, with the average decrease being -7.37%. This decline poses an important challenge to achieving the WHO's target of 90% coverage for the third dose of DTP by 2030, as evidenced by the reduction in the number of countries meeting this target from 2019 to 2022.
CONCLUSIONS
The COVID-19 pandemic has impacted vaccine coverage in America, leading to a decrease, especially across Central America.
PubMed: 38543872
DOI: 10.3390/vaccines12030238 -
Vaccines Feb 2024The underestimation of the pertussis burden prompted our study to investigate the prevalence of recent pertussis infection, its associated factors, and antibody titer...
The underestimation of the pertussis burden prompted our study to investigate the prevalence of recent pertussis infection, its associated factors, and antibody titer changes in the same individuals in Vietnam. Two cross-sectional surveys were conducted in Nha Trang in 2017 and Quang Ngai in 2019, representing high- and low-vaccine-coverage areas, respectively. Serum anti-pertussis toxin immunoglobulin-G (anti-PT IgG) ≥ 62.5 IU/mL by ELISA indicated infection in the previous 12 months. In Nha Trang, the participants of the 2017 survey were followed up in 2019. Logistic regression was used to determine the odds ratios for the characteristics associated with anti-PT IgG ≥ 62.5. The age-stratified prevalence in patients aged >2 years ranged from 2.1% (age 26-35) to 9.6% (3-5) in Nha Trang (2017) and from 7.2% (age 26-35) to 11.4% (6-15) in Quang Ngai. The prevalence tended to be higher in Quang Ngai across all age groups. Cough, recent antibiotic use, and smoking in Nha Trang were positively associated with an anti-PT IgG of ≥62.5, and having been diagnosed with pertussis and persistent cough with paroxysms/whoop in Quang Ngai were positively associated with an anti-PT IgG of ≥62.5. No nasopharyngeal swabs were positive for using real-time PCR. The geometric mean of the IgG titer ratio from 2019 to 2017 was 1.45 in the paired samples. This study emphasizes circulation across all age groups in both low- and high-vaccine-coverage settings in Vietnam, underscoring the need for continuous and standardized surveillance for a comprehensive understanding of its epidemiology.
PubMed: 38543859
DOI: 10.3390/vaccines12030225 -
Vaccine Apr 2024Maternal pertussis vaccination during the third trimester of pregnancy was implemented in 2015 in Spain, reaching a national coverage of 84% in 2019. In this ecological...
BACKGROUND
Maternal pertussis vaccination during the third trimester of pregnancy was implemented in 2015 in Spain, reaching a national coverage of 84% in 2019. In this ecological study, we investigated whether there was a change in the disease severity for pertussis in infants upon introduction of prenatal pertussis vaccination.
METHODS
We performed a time-trend analysis of infant pertussis hospitalizations during 2005-2019 in Spain using national register data. Annual hospitalization rates per 100,000 population and the mean length of hospitalization were calculated for infants < 3 months of age (target group benefiting from the prenatal vaccination) and a reference group aged 3-11 months. We compared overall rates and annual percent changes of the above variables in both groups for the time period before (2005-2014) and after vaccination introduction (2015-2019), using segmented Poisson regression.
RESULTS
During the pre-vaccination period, infants aged 0-2 months had a 5-times higher rate of pertussis hospitalization and spent on average 50 % longer in hospital than the reference group. After the maternal vaccination introduction, the hospitalization rate decreased more rapidly in infants aged 0-2 months than in infants aged 3-11 months: annual reduction of 34 % (95 % CI: 31-38) versus 26 % (95 % CI: 21-31) in the hospitalization rate and 13 % (95 % CI: 11-15) versus 6 % (95 % CI: 2-9) in the mean hospital stay, respectively. In 2019, the mean hospital stay for pertussis was about 4.5 days in both groups.
CONCLUSIONS
Maternal pertussis vaccination in Spain led to a reduction in disease severity in the target group as compared to older infants, highlighting the need for increased efforts on educating healthcare professionals on the importance of maternal vaccinations.
Topics: Infant; Humans; Female; Pregnancy; Pregnant Women; Whooping Cough; Spain; Hospitalization; Vaccination; Pertussis Vaccine
PubMed: 38531728
DOI: 10.1016/j.vaccine.2024.03.028 -
Cureus Mar 2024Introduction The administration of routine vaccinations to patients following hematopoietic stem cell transplantation (HSCT) is highly recommended. However, studies...
Introduction The administration of routine vaccinations to patients following hematopoietic stem cell transplantation (HSCT) is highly recommended. However, studies examining reasons for not completing vaccination in post-HSCT patients are lacking. Method We reviewed the medical records of patients who sought vaccination following HSCT from January 2012 to December 2018 at the Center for Infectious Diseases, Nara Medical University. Results Information regarding patients' backgrounds, administered vaccines, and reasons for not administering recommended vaccines was collected for the study. Thirty-five patients (22 men and 13 women) with a median time from HSCT to the first visit of 25 months were enrolled. Vaccine coverage was highest for diphtheria, tetanus, and acellular pertussis (DTaP) at 89% (31 patients), followed by 23-valent pneumococcal, measles/rubella/mumps, and Japanese encephalitis at 71% (25 patients), 71% (25 patients), and 63% (22 persons), respectively. However, vaccine coverage for hepatitis B, 13-valent pneumococcal, and Hib was low at 26% (three patients), 11% (four patients), and 40% (14 patients), respectively. The reason for not completing the recommended vaccination series was not provided for most cases; however, the economic barrier was cited for all vaccines. Discussion This study identified several cases in Japan where individuals stopped completing post-HSCT vaccinations due to financial constraints. Larger-scale studies may be necessary in Japan in the future for further investigation.
PubMed: 38528999
DOI: 10.7759/cureus.56842 -
Medical Science Monitor : International... Mar 2024BACKGROUND Maternal vaccination during pregnancy reduces the risk of severe course and complications from infections both for the mother and her child. As information...
BACKGROUND Maternal vaccination during pregnancy reduces the risk of severe course and complications from infections both for the mother and her child. As information regarding immunization status of pregnant women with recommended vaccines in Poland is scarce, this questionnaire-based study aimed to identify influenza, pertussis (whooping cough), and COVID-19 vaccination in 205 pregnant women in Cracow, Poland, between February and April 2023. Another objective was to assess whether any of the maternal factors might influence women's decision to inoculate during pregnancy. MATERIAL AND METHODS An anonymous and self-reported questionnaire developed specifically for this study was disseminated among postpartum women, who gave birth and were hospitalized at the Department of Obstetrics and Perinatology of the University Hospital in Cracow, Poland, between February and April 2023. Study participants were asked about their basic sociodemographic and obstetric data, as well as their immunization status regarding influenza, pertussis, and COVID-19 during their most recent pregnancy. RESULTS Only 12.2% and 23.4% of study participants received influenza and pertussis vaccinations, respectively, during pregnancy, while 61.5% of pregnant women reported vaccination with at least 2 doses of the mRNA COVID-19 vaccine. Features including type of occupation, place of residence, gravidity, and parity were statistically significant (P.
Topics: Humans; Child; Female; Pregnancy; Whooping Cough; Influenza, Human; COVID-19 Vaccines; Poland; Cross-Sectional Studies; COVID-19; Influenza Vaccines; Vaccination; Pregnancy Complications, Infectious; Gravidity
PubMed: 38525559
DOI: 10.12659/MSM.943304 -
EClinicalMedicine May 2024Identification of unvaccinated children is important for preventing deaths due to infections. Number of siblings and birth order have been postulated as risk factors for...
BACKGROUND
Identification of unvaccinated children is important for preventing deaths due to infections. Number of siblings and birth order have been postulated as risk factors for zero-dose prevalence.
METHODS
We analysed nationally representative cross-sectional surveys from 85 low and middle-income countries (2010-2020) with information on immunisation status of children aged 12-35 months. Zero-dose prevalence was defined as the failure to receive any doses of DPT (diphtheria-pertussis-tetanus) vaccine. We examined associations with birth order and the number of siblings, adjusting for child's sex, maternal age and education, household wealth quintiles and place of residence. Poisson regression was used to calculate zero-dose prevalence ratios.
FINDINGS
We studied 375,548 children, of whom 13.7% (n = 51,450) were classified as zero-dose. Prevalence increased monotonically with birth order and with the number of siblings, with prevalence increasing from 11.0% for firstborn children to 17.1% for birth order 5 or higher, and from 10.5% for children with no siblings to 17.2% for those with four or more siblings. Adjustment for confounders attenuated but did not eliminate these associations. The number of siblings remained as a strong risk factor when adjusted for confounders and birth order, but the reverse was not observed. Among children with the same number of siblings, there was no clear pattern in zero-dose prevalence by birth order; for instance, among children with two siblings, the prevalence was 13.0%, 14.7%, and 13.3% for firstborn, second, and third-born, respectively. Similar results were observed for girls and boys. 9513 families had two children aged 12-35 months. When the younger sibling was unvaccinated, 61.9% of the older siblings were also unvaccinated. On the other hand, when the younger sibling was vaccinated, only 5.9% of the older siblings were unvaccinated.
INTERPRETATION
The number of siblings is a better predictor than birth order in identifying children to be targeted by immunization campaigns. Zero-dose children tend to be clustered within families.
FUNDING
Gavi, the Vaccine Alliance.
PubMed: 38524919
DOI: 10.1016/j.eclinm.2024.102547 -
The Journal of Infection Apr 2024
Topics: Humans; Whooping Cough; China; Pertussis Vaccine; Bordetella pertussis
PubMed: 38513738
DOI: 10.1016/j.jinf.2024.106140 -
PloS One 2024Vaccination is widely considered to be one of the most important prevention measures as a health strategy. This paper examines trends in basic childhood vaccination...
Vaccination is widely considered to be one of the most important prevention measures as a health strategy. This paper examines trends in basic childhood vaccination coverage and which country and time-dependent determinants may have influenced childhood immunization rates (1-dose BCG, 1- and 3-dose DTP (diphtheria, tetanus, pertussis), 1-dose measles, and 3-dose polio) between 1980 and 2020 across 94 countries. We identify economic, inequality, demographic, health, education, labor market, environmental, and political stability factors of immunization. To do this, we use data from the annual WHO and United Nations International Children's Emergency Fund (UNICEF) coverage estimates. The empirical analysis consists of generalized estimating equation models to assess relationships between immunization rates and socioeconomic factors. Additionally, we follow the Barro and Sala-i-Martín approach to identify conditional convergence. Our findings show the strongest positive statistically significant association between immunization rates and GDP per capita, as well as births attended by skilled health staff. Moreover, our research demonstrates conditional convergence, indicating that countries converge towards different steady states. The present study brings new insights to investigating the determinants of childhood vaccination coverage and provides significant implications for health policies.
Topics: Child; Humans; Infant; Vaccination Coverage; Immunization Programs; Vaccination; Immunization; Socioeconomic Factors; Diphtheria-Tetanus-Pertussis Vaccine
PubMed: 38512892
DOI: 10.1371/journal.pone.0300404 -
Vaccine Apr 2024Previous studies have shown that vaccination against measles, mumps, and rubella (MMR) may have beneficial non-specific effects, reducing the risk of infections not...
Is vaccination against measles, mumps, and rubella associated with reduced rates of antibiotic treatments among children below the age of 2 years? Nationwide register-based study from Denmark, Finland, Norway, and Sweden.
OBJECTIVES
Previous studies have shown that vaccination against measles, mumps, and rubella (MMR) may have beneficial non-specific effects, reducing the risk of infections not targeted by the vaccine. We investigated if MMR vaccine given after the third dose of diphtheria-tetanus-acellular pertussis vaccine (DTaP3), was associated with reduced rates of antibiotic treatments.
METHODS
Register-based cohort study following children from the age of recommended MMR vaccination until age 2 years. We included 831,287 children born in Denmark, Finland, Norway, and Sweden who had received DTaP3 but not yet MMR vaccine. Cox proportional hazards regression with age as the underlying timescale and vaccination status as a time-varying exposure was used to estimate covariate-adjusted Hazard Ratios (aHRs) and inverse probability of treatment weighted (IPTW) HRs of antibiotic treatments. Summary estimates were calculated using random-effects meta-analysis.
RESULTS
Compared with only having received DTaP3, receipt of MMR vaccine after DTaP3 was associated with reduced rates of antibiotic treatments in all countries: the aHR was 0.92 (0.91-0.93) in Denmark, 0.92 (0.90-0.94) in Finland, 0.84 (0.82-0.85) in Norway, and 0.87 (0.85-0.90) in Sweden, yielding a summary estimate of 0.89 (0.85-0.93). A stronger beneficial association was seen in a negative control exposure analysis comparing children vaccinated with DTaP3 vs two doses of DTaP.
CONCLUSIONS
Across the Nordic countries, receipt of MMR vaccine after DTaP3 was associated with an 11% lower rate of antibiotic treatments. The negative control analysis suggests that the findings are affected by residual confounding. Findings suggest that potential non-specific effects of MMR vaccine are of limited clinical and public health importance for the milder infections treated out-of-hospital in the Nordic setting.
Topics: Child; Child, Preschool; Humans; Infant; Cohort Studies; Denmark; Finland; Measles; Measles-Mumps-Rubella Vaccine; Mumps; Norway; Rubella; Sweden; Vaccination
PubMed: 38508926
DOI: 10.1016/j.vaccine.2024.03.026 -
MSphere Apr 2024Pertussis (whooping cough) is a reemergent, highly contagious respiratory infection of public health concern. Infants prior to initiation of their primary vaccination...
UNLABELLED
Pertussis (whooping cough) is a reemergent, highly contagious respiratory infection of public health concern. Infants prior to initiation of their primary vaccination series are the most vulnerable to severe infection, and even death. Vaccination during pregnancy is an efficacious means of reducing infection in infants. This approach relies on boosting maternal immunity and passive transfer of antibodies to the infant via placenta and breast milk. Similarly, maternal vaccination post-partum can enhance maternal-infant immunity. To support the analysis of pertussis immunity in the context of maternal-infant immunization, we developed a high throughput multiplex assay for simultaneous quantification of serum IgG antibodies against pertussis vaccine antigens: pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN), and fimbriae (FIM2/3), and against tetanus (TT) and diphtheria toxoids (DT), using the Meso Scale Discovery (MSD) platform. The assay was qualified, and specificity, sensitivity, accuracy, precision, linearity, and robustness were demonstrated. The assay was subsequently adapted for quantification of IgG and IgA in breast milk. Applied to a serological survey of pregnant women living in the United States and sub-Saharan Africa, this method revealed differences in magnitude and breadth of antibody profile, consistent with history of vaccination. A longitudinal analysis of Tdap responses in women vaccinated post-partum demonstrated a rapid increase in serum IgG that remained elevated for up to 24 months. Likewise, high levels of vaccine-specific IgA and IgG antibodies were present in breast milk, although they exhibited faster decay. This multiplex MSD assay is a reliable and practical tool for quantification of pertussis, tetanus, and diphtheria antibodies in serum and breast milk in serosurveys or vaccine studies.
IMPORTANCE
Pertussis (whooping cough) has reemerged in recent years. Vaccination during pregnancy is an effective approach to prevent illness during the first months of life. We developed a multiplex assay for quantification of pertussis, tetanus, and diphtheria serum antibodies using the Meso Scale Discovery (MSD) platform; the method was qualified, and specificity, precision, accuracy, linearity, and limits of quantification were defined. It was also adapted for quantification of antibodies in breast milk. We successfully determined serostatus in women from different regions and with different vaccination histories, as well as responses to Tdap in blood and breast milk post-partum. This is the first description of a multiplex assay for the quantification of pertussis, tetanus, and diphtheria antibodies in breast milk.
Topics: Humans; Female; Antibodies, Bacterial; Milk, Human; Whooping Cough; Immunoglobulin G; Diphtheria-Tetanus-acellular Pertussis Vaccines; Pregnancy; Adult; Diphtheria; Tetanus; Young Adult; Vaccination; Immunity, Maternally-Acquired
PubMed: 38497618
DOI: 10.1128/msphere.00527-23