Vaccine Series Research Articles

An insight from machine learning perspective for COVID-19 survival prediction in Malaysia based on demographic factor

Malaysia reported its first imported COVID-19 case on 23 January 2020, which marked the country’s first confirmed positive case. The first case in Malaysia was from eight close contacts in Johor. The global health landscape has been significantly impacted by the COVID-19 pandemic, with mortality or survival being critical outcomes of interest. This study aims to predict COVID-19 survival occurrences in Malaysia by utilizing machine learning approaches based on demographic factors. The dataset used in this study comprises demographic information of 2,151,315 COVID-19 patients, including nationality, regions, age groups, gender, medical history, vaccine brands, and the number of vaccine doses received between 2020 and 2022. Four machine learning algorithms, namely Logistic Regression, Naïve Bayes, Support Vector Machine, and Artificial Neural Network were employed to assess the relationship between demographic factors and COVID-19 survival. To evaluate the model performance, the datasets are categorized into imbalanced and balanced (down-sampling). The results indicate that the balanced dataset (down-sampling) outperforms the imbalanced dataset in terms of overall accuracy, sensitivity, specificity, precision, and Area Under the Curve (AUC). Based on the analysis, the Artificial Neural Network (ANN) classifier exhibited the highest performance with a specificity 95.2% on a balanced dataset. The model excels in accurately identifying survivors, thereby minimizing false mortality predictions and is selected as the best model for predicting COVID-19 survival. Its capacity to process larger sample sizes, combined with numerous interconnected nodes, enables it to identify complex patterns and extract meaningful insights from diverse datasets, such as demographic factors. Additionally, the optimization of parameters, including the number of layers, learning rate, and activation functions, significantly contributed to its superior accuracy. The study identifies that those of chronic diseases, male, and aged 45 and above as the notable factors associated with lower survival rates among COVID-19 patients. The findings underscore the importance of completing the vaccination series by obtaining at least the second dose, as the first dose alone may not offer sufficient protection. In conclusion, this study successfully achieves its objectives by identifying the optimal dataset configuration and predictive model for forecasting COVID-19 survival based on demographic factors. This network could serve as a benchmark model classifier, offering a valuable tool to predict and promote vaccinations, as well as optimize the general healthcare system during the pandemic outbreak. The study not only contributes to the theoretical understanding of effective COVID-19 prediction but also emphasizes the practical implications of integrating advanced machine learning techniques into pandemic management strategies. Future research can build upon these findings by exploring additional machine learning techniques and considering geographical and environmental factors to further enhance the accuracy of long-term predictions.

Updated Review for Guidelines for Cervical Cancer Screening in Immunosuppressed Women Without HIV Infection.

The purpose of this review was to examine new evidence since our 2019 guidelines for cervical cancer (CC) screening in non-HIV immunocompromised persons and to provide updated recommendations based on literature review and expert opinion. In addition, human papillomavirus (HPV) vaccine efficacy in these populations was reviewed. A literature search was performed similar to our previous publication but was conducted through March 2023. Risk of CC, squamous intraepithelial lesions, and HPV infection in those living with solid organ transplant (SOT), end-stage renal disease (ESRD), hematopoietic stem cell transplant (HSCT), and autoimmune diseases (AID), specifically systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and inflammatory bowel disease (IBD) with addition of multiple sclerosis (MS) were researched. This update also summarizes data available on newer disease-modifying therapies (DMTs) including monoclonal antibodies (MABs). We then made recommendations for HPV vaccine administration, and screening using either general population guidelines or increased surveillance, the latter based on following current recommendations for women living with HIV. Additionally, the literature search included antibody response to HPV vaccines and recommendations for their administration for these same conditions. Based on the reviewed risks, evidence continued to support those persons living with SOT, ESRD, HSCT, and SLE, whether on immunosuppressant therapy or not, had an increased risk of HPV, squamous intraepithelial lesions, and CC whereas there was weak evidence that those persons with IBD, RA, and MS not on immunosuppressants were at risk. Data on persons using DMT/MAB were conflicting. Data showed that patients on certain immunosuppressants had lower antibody titers following HPV vaccination. There were no studies on HPV vaccine efficacy. Following US Center for Disease Control and Prevention HIV Cervical cancer screening (CCS) guidelines is recommended for the following: SOT, ESRD, HSCT, and SLE whether on immunosuppressants or not, and IBD, RA, and MS on immunosuppressants. Shared decision-making about increased surveillance for IBD and RA not on immunosuppressants and persons on any DMT or MAB is reasonable based on conflicting data. Human papillomavirus vaccination should not change the recommendations for increased CC surveillance. A 3-dose series of the HPV vaccine is recommended for all age-eligible patients starting at 9 years of age, with catch-up to 26 years of age. Vaccination from age 27 up to age 45 years per Advisory Committee on Immunization Practices guidelines should be considered in shared decision-making. When possible, HPV vaccine series should be initiated and completed before SOT or initiation of DMT/MAB. For HSCT, the vaccine series should be readministered along with other childhood vaccines.

Invalid Vaccine Doses Among Children Aged 0 to 35Months: 2011 to 2020.

Vaccine doses provided outside the Advisory Committee on Immunization Practices for minimum and maximum ages of vaccination and minimum intervals between doses are considered invalid. Our objective was to quantify the prevalence of and factors associated with invalid doses among US children aged 0 to 35months. We analyzed provider-verified vaccination records from the nationally representative 2011-2020 National Immunization Survey-Child. We quantified the number of children with at least 1 invalid vaccine dose overall, by survey year, and by vaccine type. Among children who received vaccine doses before the minimum age or minimum dose interval, we quantified the prevalence of receiving extra doses such that series were completed with the recommended number of valid doses. We used logistic regression models to identify factors associated with receipt of an invalid vaccination. Of 161 187 children, 22 209 (weighted percent: 15.4%, 95% CI, 15.0%-15.8%) had an invalid vaccine dose. Of children with a minimum age or minimum interval invalid dose, 44.9% (95% CI, 43.2%-46.6%) received extra doses and completed the series. The highest prevalence of invalid doses was for 3-dose rotavirus (n = 5733, 4.4%), with the first dose being administered after the maximum age (n = 3996, 3.1%). Overall, the percentage of children with an invalid dose decreased from 2011 (16.9%) to 2020 (12.5%). Children who moved across state lines vs not (adjusted odds ratio: 1.5 [95% CI, 1.4-1.6]) had higher odds of an invalid vaccine dose. Although invalid vaccine doses have decreased over time, many children with invalid doses lacked the doses necessary to complete a vaccine series.

Expanded Recommendations for Use of Pneumococcal Conjugate Vaccines Among Adults Aged ≥50 Years: Recommendations of the Advisory Committee on Immunization Practices - United States, 2024.

Before October 2024, the Advisory Committee on Immunization Practices (ACIP) recommended use of a pneumococcal conjugate vaccine (PCV) for all adults aged ≥65 years, as well as for those aged 19-64 years with risk conditions for pneumococcal disease who have not received a PCV or whose vaccination history is unknown. Options included either 20-valent PCV (PCV20; Prevnar20; Wyeth Pharmaceuticals) or 21-valent PCV (PCV21; CAPVAXIVE; Merck Sharp & Dohme) alone or 15-valent PCV (PCV15; VAXNEUVANCE; Merck Sharp & Dohme) in series with 23-valent pneumococcal polysaccharide vaccine (PPSV23; Pneumovax23; Merck Sharp & Dohme). There are additional recommendations for use of PCV20 or PCV21 for adults who started their pneumococcal vaccination series with 13-valent PCV (PCV13; Prevnar13; Wyeth Pharmaceuticals). The ACIP Pneumococcal Vaccines Work Group employed the Evidence to Recommendations framework to guide its deliberations on expanding the age-based PCV recommendation to include adults aged 50-64 years. On October 23, 2024, ACIP recommended a single dose of PCV for all PCV-naïve adults aged ≥50 years. Recommendations for PCVs among adults aged 19-49 years with risk conditions and PCV13-vaccinated adults have not changed from previous recommendations. This report summarizes evidence considered for these recommendations and provides updated clinical guidance for use of PCV.

Human papillomavirus vaccination coverage among adolescent boys and girls in the United States: A birth year cohort analysis of the National Immunization Survey-Teen, 2016–2022.

ObjectiveTo evaluate human papillomavirus (HPV) vaccination coverage among adolescents in the U.S. using birth cohort analysis. MethodsWe conducted a birth cohort analysis among adolescents born during 1999–2009 using National Immunization Survey-Teen (NIS-Teen), a random-digit dialed household telephone survey that also includes vaccination data from providers. We analyzed 131,553 records from 2016 to 2022 NIS-Teen data to determine: trends in coverage with ≥1 HPV vaccine dose before age 13 years and cumulative coverage from age 13–17 years; sociodemographic factors associated with HPV vaccination before age 13 years; missed HPV vaccination opportunities and the potential achievable coverage if opportunities were not missed; and trends in completion of HPV vaccination series. Regression analysis and Kaplan-Meier method provided the average percentage increase in coverage, and cumulative coverage from age 13–17 years stratified by birth cohorts, respectively. ResultsHPV vaccination initiation before age 13 years increased from 27.0 % among adolescents born in 1999 to 69.8 % among those born in 2009. Overall, cumulative percent with ≥1 HPV vaccine dose increased from 51.3 % before age 13 years to 74.9 % through age 17 years. Having a preventive visit at ages 11–12 years and being insured were associated with higher ≥1 HPV vaccine dose coverage. Among the 38,568 (29.3 %) adolescents unvaccinated for HPV, 31,513 (82.5 %) missed ≥1 HPV vaccination opportunity. The potential achievable coverage if opportunities were not missed was 94.8 %. Completion of HPV vaccination series before age 13 years increased from 10.3 % among adolescents born in 1999 to 42.2 % among those born in 2009. ConclusionsCoverage with ≥1 HPV vaccine dose increased by birth cohort among adolescents born 1999–2009 but remained suboptimal, especially among uninsured adolescents. Missed opportunities may be reduced by effective HPV vaccination implementation and uptake strategies and by administering all recommended vaccines during the same visit.

Effectiveness of primary series, first, and second booster vaccination of monovalent mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections and severe diseases during the SARS-CoV-2 omicron BA.5 epidemic in Japan: vaccine effectiveness real-time surveillance for SARS-CoV-2 (VERSUS)

ABSTRACT Background This study aimed to evaluate VE of primary, first, and second booster ancestral-strain monovalent mRNA COVID-19 vaccination against symptomatic infections and severe diseases in Japan. Methods We conducted a test-negative case-control study. We included medically attended episodes and hospitalizations involving individuals aged ≥ 16 with signs and symptoms from July to November 2022, when Omicron BA.5 was dominant nationwide. To evaluate VE, we calculated adjusted ORs of vaccination among test-positive versus test-negative individuals using a mixed-effects logistic regression. Results For VE against symptomatic infections among individuals aged 16 to 59, VE of primary vaccination at > 180 days was 26.1% (95% CI: 10.6–38.8%); VE of the first booster was 58.5% (48.4–66.7%) at ≤ 90 days, decreasing to 41.1% (29.5–50.8%) at 91 to 180 days. For individuals aged ≥ 60, VE of the first booster was 42.8% (1.7–66.7%) at ≤ 90 days, dropping to 15.4% (−25.9–43.2%) at 91 to 180 days, and then increasing to 44.0% (16.4–62.5%) after the second booster. For VE against severe diseases, VE of the first and second booster was 77.3% (61.2–86.7%) at ≤ 90 days and 55.9% (23.4–74.6%) afterward. Conclusion mRNA booster vaccination provided moderate protection against symptomatic infections and high-level protection against severe diseases during the BA.5 epidemic in Japan.

Vaccine Hesitancy and Associated Factors Amongst Health Professionals: A Scoping Review of the Published Literature.

Background/Objectives: Healthcare professionals (HCPs) hold significant influence over public attitudes toward vaccinations. Studies suggest that HCPs are hesitant towards the coronavirus disease 2019 (COVID-19) vaccines. This hesitancy could lead to lower vaccination rates in the community. Therefore, this scoping review aimed to assess the extent of hesitancy towards COVID-19 booster doses among HCPs and identify the associated factors. Methods: A comprehensive search was conducted in the PubMed and Scopus databases from April to August 2024, using keywords related to COVID-19, vaccine hesitancy, HCPs, and booster vaccination. Studies that had been peer-reviewed, published in English after 2022, and focused on the hesitancy of the COVID-19 booster dose hesitancy among HCPs were included. Out of the 6703 studies screened, 24 studies were included. Results: Most of the HCPs have received their initial series of COVID-19 vaccinations. However, there is a lower rate of uptake for booster doses, with hesitancy rates ranging from 12% to 66.5%. Hesitancy rates varied significantly across continents, with Asia, Africa, and Europe ranging from 19.7% to 66.5%, 27% to 46.1%, 14% to 60.2%, respectively. Hesitancy was reported to be influenced by various factors, including concerns about vaccine safety, necessity, and effectiveness of these vaccines. In addition, the hesitancy regarding booster doses was also found to be influenced by factors like age, gender, profession, and previous COVID-19. Physicians, nurses, and pharmacists exhibited vaccine hesitancy rates ranging from 12.8% to 43.7%, 26% to 37%, and 26% to 34.6%, respectively. Conclusions: Our review underscores the hesitancy among HCPs towards receiving booster doses across countries around the world and explores the underlying factors. These findings provide valuable insights for the design of future pandemic vaccination programs.

Socioeconomic/health-related factors associated with HPV vaccination initiation/completion among females of paediatric age: A systematic review with meta-analysis.

To systematically identify, appraise, and summarise published evidence on individual socioeconomic and health-related factors associated with human papillomavirus (HPV) vaccination initiation and completion among females of paediatric age. A global systematic review with meta-analysis (PROSPERO: CRD42023445721). We performed a literature search in December 2022 and supplemented the search on August 1, 2023. Appropriate data were pooled using an inverse variance, random-effects model and the results were expressed as odds ratios, with 95% confidence intervals. A statistically significant point pooled increased/decreased odds of 30-69% was regarded to be strongly associated, and ≥70% was very strongly associated. We included 83 cross-sectional studies. Among several significantly associated factors, being an older girl: 1.67 (1.44-1.93), having health insurance: 1.41 (1.16-1.72), and being in a public school: 1.54 (1.05-2.26) strongly increased the odds of vaccination initiation, and nativity in the country of study: 1.82 (1.33-2.50), use of contraception: 2.00 (1.16-3.46), receipt of influenza vaccination: 1.75 (1.54-2.00) and having visited a healthcare provider: 1.85 (1.51-2.28) in the preceding year very strongly increased the odds of vaccination initiation. Likewise, being an older girl: 1.36 (1.23-1.49) and having visited a healthcare provider in the preceding year: 1.46 (1.05-2.04) strongly increased the odds of vaccination series completion, and school-based vaccination: 3.08 (1.05-9.07), having health insurance: 1.72 (1.27-2.33), and receipt of influenza vaccination in the preceding year: 1.72 (1.62-1.83) very strongly increased the odds of vaccination series completion. We made similar observations when the studies were limited to the United States. Several individual socioeconomic/health-related factors may determine initiating and completing the HPV vaccination series among paediatric females. These factors provide insights that may be key to identifying girls at increased risk of not being vaccinated and may aid targeted public health messaging.

Antibody titer trends after SARS-CoV-2 vaccination in patients aged 12 to 25 years with underlying diseases.

Whereas declines in antibody titers after SARS-CoV-2 vaccination have been reported, most reports are predominantly from adults. Long-term trends in SARS-CoV-2 antibody titers after the first BNT162b2 vaccination series in children and young adults with underlying diseases remain less studied. This prospective single-center observational cohort study enrolled patients aged 12-25 years with underlying diseases who received the first BNT162b2 vaccination series. At least three longitudinal antibody titers were evaluated during the first year following vaccination. Among 429 study subjects, 61 patients with at least three subsequent antibody titer measurements were included. The median (interquartile range [IQR]) time intervals from the vaccination to the first, second, and third antibody measurements were 43 (30-56), 126 (110-155), and 224 (207-256) days, and antibody titers declined with median (IQR) values of 2310 (1440-3515), 2010 (1165-3055), and 1410 (904-2195) U/mL, respectively. In 35 immunocompetent patients, the antibody titers decreased consistently in each measurement. In contrast, the antibody titers in immunocompromised patients remained stable between the first and second measurements, but declined by the third. A two-way ANOVA revealed that time was a more significant factor than immunocompromised status for the declines in antibody titers. In patients aged 12-25 years with underlying diseases, antibody titers in immunocompromised patients after SARS-CoV-2 vaccination were lower than in immunocompetent patients in the early post-vaccination period, but they maintained titers similar to the immunocompetent counterpart during the long-term follow-up.

Effectiveness of hepatitis A immunisation after paediatric liver transplantation: A retrospective observational analysis.

This retrospective study aimed to investigate the response to hepatitis A virus (HAV) immunisation following liver transplantation. We analysed, 234 vaccination records of 284 children who underwent liver transplantation between January 2003 and July 2021, including annual serological results. Of the 120 HAV-naïve patients, approximately 71% and 83% showed seroconversion after receiving one and two vaccine doses, respectively. The third dose increased the seroconversion rate to 93%. In multivariable logistic regression analysis, the number of vaccine doses and age at first vaccine dose were independently associated with seroconversion. In contrast, additional immunosuppression with mycophenolate mofetil (MMF) was negatively associated with seroconversion. In Cox regression analysis of all 96 seroconverted children, younger age at first vaccination and additional immunosuppression with either MMF or prednisolone were identified as independent risk factors for the early loss of HAV immunity. In summary, HAV immunisation with the three-dose vaccination series is recommended for paediatric liver transplant recipients. Antibody testing and booster vaccinations, if necessary, are recommended, especially for those living in endemic areas or with additional immunosuppressive treatments.

Seropositivity of Anti-HBs Titer Among College Students Several Years After Completion of the Primary Hepatitis B Vaccination Series

Seropositivity of Anti-HBs Titer Among College Students Several Years After Completion of the Primary Hepatitis B Vaccination Series

COVID-19 Testing Behavior as a Predictor of COVID-19 Vaccination in Southeastern Louisiana: A Longitudinal Cohort Study.

Background: Global COVID-19 vaccination effort faces the challenges of vaccine hesitancy and resistance, rooted in misinformation and institutional distrust. Addressing these barriers with customized messaging is essential, yet the relationship between vaccine hesitancy and other health-seeking behaviors, like COVID-19 testing, has been underexplored. Method: This study assessed COVID-19 vaccine uptake in Southeastern Louisiana across 10 pharmacies and clinics in areas with historically high rates of COVID-19 infection. Using a longitudinal cohort design from Fall 2022 through Fall 2023, a total of 377 participants from diverse backgrounds were surveyed while seeking routine care at partner organizations. Baseline data was collected on demographics, vaccine knowledge, attitudes, and test-seeking behaviors. Information on COVID-19 testing and vaccination were self-reported and verified, as applicable, in the patient's medical records. All data was analyzed using descriptive statistics, log-binomial to yield risk ratios, and an ordinal logistic regression for vaccine series completion. Results: Among the 377 participants, 207 were unvaccinated while 170 received the vaccine. Among the unvaccinated individuals, 53 received a half-dose, 97 a full dose, and 14 a booster. Notably, 75% of unvaccinated and 89% of vaccinated participants underwent COVID-19 testing. Individuals who were tested were 1.71 times more likely to be vaccinated (95% CI 1.03, 2.84), while previous vaccine refusal was associated with lower vaccine acceptance (0.77; 95% CI 0.54, 1.09). In the bivariate and multivariate analysis, COVID-19 testing behavior was positively associated with COVID-19 vaccine uptake. Conclusions: Exploring the connection between COVID-19 testing and vaccination provides valuable insights for future public health messaging to mitigate vaccine hesitancy.

Long-term serological response and boostability of intradermal rabies immunization: A retrospective chart review.

Rabies vaccines in Canada are currently labeled for intramuscular use only; however, intradermal vaccine administration may be equally effective. This study aims to assess the immediate and long-term (≥ 2years) serological response and boostability of intradermal administration of rabies vaccine for pre-exposure prophylaxis. This retrospective cohort study was conducted using data from electronic medical records at the Winnipeg Regional Health Authority Travel Health & Tropical Medicine Services Clinic. Individuals ≥ 18years of age at time of vaccination who received at least 3 × 0.1mL doses of intradermal rabies vaccine were included. All charts were reviewed to extract post-primary immunization and post-booster serology results, and t-tests were conducted to evaluate seroprotection (defined as serology ≥ 0.5IU/mL). A total of 324 individuals received an intradermal rabies primary pre-exposure vaccination series with follow-up serology within 90days. Seroprotection was observed in 96% (GMT = 3.36IU/mL, 95% CI 3.07-3.68). Of these, 68 had serology results 1.8-2.5years later, with seroprotection declining to 44% (GMT = 0.52IU/mL, 95%CI 0.41-0.65). However, 100% seroprotection was observed in those who received an intradermal booster dose at ≥ 2years with follow-up serology (n = 20, GMT = 4.7IU/mL, 95%CI 3.7-6.2). Intradermal administration of a primary pre-exposure rabies vaccine series demonstrates a strong serological response. While titers decline over time, the robust serological response demonstrated after a single intradermal booster vaccine dose suggests that a strong anamnestic immune response was maintained. This finding supports existing evidence that intradermal administration of rabies vaccines can be used effectively for rabies pre-exposure and post-exposure prophylaxis.

Seroepidemiology of pertussis immunity in five provinces of China: A population-based, cross-sectional study

ABSTRACT This study aimed to evaluate the seroprevalence of Bordetella pertussis and persistence of antibodies following vaccination. We recruited 6060 healthy subjects from five provinces of China during 2017–2018. Serum IgG antibodies against pertussis toxin (anti-PT IgG) and filamentous hemagglutinin (anti-FHA IgG), and serum IgA antibodies against pertussis toxin (anti-PT IgA) were measured by ELISA. Geometric mean concentration (GMC), seropositivity rate, and recent infection rate were calculated. Among 0–6 years-olds, the anti-PT IgG, anti-PT IgA, and anti-FHA IgG GMCs were 6.4 IU/ml (95% CI 6.1–6.8), 2.8 IU/ml (95% CI 2.7–2.8), and 13.3 IU/ml (95% CI 12.4–14.2), respectively. The anti-PT IgG GMC increased in accordance with the primary vaccination series (4–6 months) and the toddler booster (18–24 months), but declined thereafter through to age 5 years [4.7 IU/ml (95% CI 4.2–5.4)]. The seropositivity rate of pertussis in >6 year-olds was 9.0% (95% CI 8.1–9.9) and the recent infection rate was 3.3% (95% CI, 2.7–3.8). Recent infection rate began to increase from 6 years of age, with peaks at 9, 20, 40, and ≥60 years of age. The anti-PT IgG GMCs of children aged 0–6 years who were vaccinated with DTaP, DTaP-IPV//PRP～T, and DTaP-Hib were 5.9 IU/ml (95% CI 5.6–6.3), 20.7 IU/ml (95% CI 15.6–27.8), and 11.7 IU/ml (95% CI 7.5–18.1) (p < .001), respectively (p < .001). Pertussis vaccination improves anti-PT IgG levels, however these wane soon after vaccination. Sero-estimated recent infection rates appear to increase from school age into adolescence and adulthood. Pertussis vaccine boosters should be considered in these age groups.

Tenofovir and Hepatitis B Virus Transmission During Pregnancy

Standard care for preventing mother-to-child transmission (MTCT) of hepatitis B virus (HBV) in highly viremic mothers consists of maternal antiviral prophylaxis beginning at gestational week 28 combined with an HBV vaccine series and HBV immune globulin (HBIG) at birth. However, HBIG is unavailable in some resource-limited areas. To determine whether initiating tenofovir disoproxil fumarate (TDF) at gestational week 16 combined with HBV vaccinations for infants is noninferior to the standard care of TDF at gestational week 28 combined with HBV vaccinations and HBIG for infants in preventing MTCT in mothers with HBV and high levels of viremia. An unblinded, 2-group, randomized, noninferiority clinical trial was conducted in 7 tertiary care hospitals in China. A total of 280 pregnant individuals (who all identified as women) with HBV DNA levels greater than 200 000 IU/mL were enrolled between June 4, 2018, and February 8, 2021. The final follow-up occurred on March 1, 2022. Pregnant individuals were randomly assigned to receive either TDF starting at gestational week 16 with HBV vaccinations for the infant or TDF starting at gestational week 28 with HBV vaccinations and HBIG administered to the infant. The primary outcome was the MTCT rate, defined as detectable HBV DNA greater than 20 IU/mL or hepatitis B surface antigen positivity in infants at age 28 weeks. Noninferiority was established if the MTCT rate in the experimental group did not increase by more than an absolute difference of 3% compared with the standard care group, as measured by the upper limit of the 2-sided 90% CI. Among 280 pregnant individuals who enrolled in the trial (mean age, 28 years; mean gestational age at enrollment, 16 weeks), 265 (95%) completed the study. Among all live-born infants, using the last observation carried forward, the MTCT rate was 0.76% (1/131) in the experimental group and 0% (0/142) in the standard care group. In the per-protocol analysis, the MTCT rate was 0% (0/124) in the experimental group and 0% (0/141) in the standard care group. The between-group difference was 0.76% (upper limit of the 2-sided 90% CI, 1.74%) in all live-born infants and 0% (upper limit of the 2-sided 90% CI, 1.43%) in the per-protocol analysis. Both comparisons met the criterion for noninferiority. Rates of congenital defects and malformations were 2.3% (3/131) in the experimental group and 6.3% (9/142) in the standard care group (difference, 4% [2-sided 95% CI, -8.8% to 0.7%]). Among pregnant women with HBV and high levels of viremia, TDF beginning at gestational week 16 combined with HBV vaccination for infants was noninferior to the standard care of TDF beginning at gestational week 28 combined with HBIG and HBV vaccination for infants. These results support beginning TDF at gestational week 16 combined with infant HBV vaccine to prevent MTCT of HBV in geographic areas where HBIG is not available. ClinicalTrials.gov Identifier: NCT03476083.

Variation in the time to complete the primary COVID-19 vaccine series by race, ethnicity, and geography among older US adults

IntroductionRacial and ethnic disparities in COVID-19 vaccine access are well-documented; however, few studies have examined whether racial disparities are modified by other factors, including geographic location and area-level deprivation. MethodsWe conducted an observational study using the COVVAXAGE database. Medicare beneficiaries who received the COVID-19 vaccine primary series (two doses) between 01/01/2021 and 12/31/2021 were included. Racial differences in the time between doses was assessed by urbanicity using g-formula methods. ResultsWe identified 11,924,990 beneficiaries (mean age = 75.4; 60 % female; 80 % White). Most beneficiaries (97.1 %) received their second vaccine on time. Delayed second doses were more common among beneficiaries who were Black (RRdelayed = 1.30, 95 %CI = 1.28–1.31) and rural (RRdelayed = 1.27, 95 %CI = 1.25–1.29) relative to White and urban beneficiaries. Racial disparities in delayed vaccinations varied in magnitude by degree of urbanicity. ConclusionsMost beneficiaries received their second COVID-19 vaccine on time. Racial disparities were observed and shown to vary by geographic area.

Direct and indirect effects of hepatitis B vaccination in four low- and middle-income countries

Population-level vaccination effects of the hepatitis B vaccine were investigated in four low- and middle-income countries with different levels of vertical and horizontal transmission. Indirect vaccination effects constitute a large proportion of overall vaccination effects of the vaccination programmes in all four countries (over 70% by 2030 in all four countries). However, countries with higher levels of vertical transmission benefit less from indirect vaccination effects from the infant hepatitis B vaccine series during the first decades of the vaccination programme, making the birth dose vaccine more important in these countries. Vaccination, even at levels that do not fully control transmission, has a great effect on the development of disease as it also increases the average age of infection, thereby causing a decrease in the number of chronic infections relative to the number of acute infections.

Behaviorally Informed Text Message Nudges to Schedule COVID-19 Vaccinations: A Randomized Controlled Trial.

Vaccine hesitancy, especially related to COVID-19 vaccinations among Veterans, may limit uptake. Behaviorally informed text-based messages have the potential to improve uptake of COVID-19 vaccinations. To evaluate the impact of two different behaviorally informed text message nudges on COVID-19 vaccine scheduling and completion, compared to standard control message. Prospective, three-arm patient-level randomized quality improvement trial. Between March and May 2021, 20,523 Veterans were eligible for the initial series of COVID-19 vaccination, enrolled at two large Veterans Health Administration sites. Arm 1 (Control): standard scheduling message; Arm 2 (Social Good): standard message plus behaviorally informed text message "When you get a vaccine now, you help protect yourself, your family, and your community"; and Arm 3 (Scarcity): standard plus behaviorally informed text message "Only a limited number of vaccine appointments are available." Outcomes were vaccine scheduling and/or completion rate within 7 days of receipt of text message (primary), and within 14 days and 30 days after receipt of text message (secondary). Veterans had an overall rate of 19% of scheduling or receiving a vaccination in 7 days. In our adjusted intention-to-treat analysis, we found no difference between intervention social good or scarcity (aOR 0.98, 95% CI, 0.88-1.09, for both arms) compared to standard scheduling message. We found no statistical differences in our secondary outcomes. During the initial phases of vaccine roll-out, two behaviorally informed text messages did not increase COVID-19 vaccination rates among Veterans compared to a standard scheduling message.

Magnitude of antigen-specific T-cell immunity the month after completing vaccination series predicts the development of long-term persistence of antitumor immune response

BackgroundFor best efficacy, vaccines must provide long-lasting immunity. To measure longevity, memory from B and T cells are surrogate endpoints for vaccine efficacy. When antibodies are insufficient for protection, the...

Health Care Delivery Site- and Patient-Level Factors Associated With COVID-19 Primary Vaccine Series Completion in a National Network of Community Health Centers.

Objectives. To assess multilevel factors associated with variation in COVID-19 vaccination rates in a US network of community health centers. Methods. Using multilevel logistic regression with electronic health record data from ADVANCE (Accelerating Data Value Across a National Community Health Center Network; January 1, 2022-December 31, 2022), we assessed associations between health care delivery site-level (n = 1219) and patient-level (n = 1 864 007) characteristics and COVID-19 primary vaccine series uptake. Results. A total of 1 337 440 patients completed the COVID-19 primary vaccine series. Health care delivery site characteristics were significantly associated with lower series completion rates, including being located in non-Medicaid expansion states and isolated or rural communities and serving fewer patients. Patient characteristics associated with significantly lower likelihood of completing the vaccine series included being Black/African American or American Indian/Alaska Native (vs White), younger age, lower income, being uninsured or publicly insured (vs using private insurance), and having fewer visits. Conclusions. Both health care delivery site- and patient-level factors were significantly associated with lower COVID-19 vaccine uptake. Community health centers have been a critical resource for vaccination during the pandemic. (Am J Public Health. 2024;114(11):1242-1251. https://doi.org/10.2105/AJPH.2024.307773).