Impact of pregnancy on polyfunctional IgG and memory B cell responses to Tdap immunization.

BACKGROUND: Maternal pertussis immunization using Tdap vaccine is recommended in many countries to protect newborns from severe post-natal infection. Immunological changes during pregnancy may influence the response to vaccines. The quality of IgG and memory B cell responses to Tdap immunization in pregnant women has not yet been described. METHODS: The impact of pregnancy on the response to Tdap vaccination was assessed by comparing humoral immune responses in 42 pregnant and 39 non-pregnant women. The levels of serum pertussis antigens and tetanus toxoid-specific IgG, IgG subclasses, IgG Fc-mediated effector functions, as well as memory B cell frequencies were assessed before and at several time points after vaccination. RESULTS: Tdap immunization induced similar levels of pertussis and tetanus-specific IgG and IgG subclasses in pregnant and non-pregnant women. Pregnant women produced IgG promoting complement deposition, and neutrophils and macrophages phagocytosis at levels comparable to non-pregnant women. They were also able to expand pertussis and tetanus-specific memory B cells at similar frequencies as non-pregnant women, suggesting equivalent "boostability". Higher levels of vaccine-specific IgG, IgG subclasses, and IgG Fc-mediated effector functions were detected in cord blood as compared to maternal blood, indicating efficient transport across the placenta. CONCLUSIONS: This study demonstrates that pregnancy does not affect the quality of effector IgG and memory B cell responses to Tdap immunization and that polyfunctional IgG are efficiently transferred across the placenta. REGISTRY'S URL AND THE TRIAL'S REGISTRATION NUMBER: ClinicalTrials.Gov (NCT03519373).

Vaccination in pregnancy.

The evidence indicates that pregnancy is associated with increased severity of some infectious diseases. Given the high maternal morbidity associated with influenza in pregnancy and the high neonatal morbidity and mortality associated with pertussis, the traditionally two recommended vaccines during pregnancy were those against influenza and Tdap (tetanus toxoid, reduced diphtheria toxoid and acellular pertussis) vaccines. The recent COVID-19 pandemic introduced a third vaccine that after much debate is now recommended for all pregnant women. Other vaccines can be offered based for high-risk pregnant women, and only when the benefits of receiving them outweigh the risks. The soon expected vaccines against group B streptococcus infection and respiratory syncytial virus infection will be a breakthrough in reducing perinatal mortality. In this paper, the recommendations for administration of each vaccine during pregnancy are discussed.

Risk of New Retinal Vascular Occlusion After mRNA COVID-19 Vaccination Within Aggregated Electronic Health Record Data.

Importance: New-onset retinal vascular occlusion (RVO) occurring acutely after messenger RNA (mRNA) COVID-19 vaccination has been described in recent literature. Because RVO can cause vision loss or blindness, an epidemiologic investigation evaluating this potential association is of great importance to public health. Objective: To investigate how often patients are diagnosed with new RVO acutely after the mRNA COVID-19 vaccine compared with influenza and tetanus, diphtheria, pertussis (Tdap) vaccines. Design, Setting, and Participants: A retrospective population-based cohort design using the TriNetX Analytics platform, a federated, aggregated electronic health record (EHR) research network containing the deidentified EHR data of more than 103 million patients, was used to examine aggregate EHR data. Data were collected and analyzed on October 20, 2022. Data on patients within the TriNetX Analytics platform were searched for the presence of vaccination Common Procedural Technology codes, and instances of newly diagnosed RVO within 21 days of vaccination were recorded and reported. Propensity score matching based on demographic characteristics (age, sex, race and ethnicity) and comorbidities (diabetes, hypertension, and hyperlipidemia) was performed between vaccination groups for evaluation of relative risks (RRs). Main Outcomes and Measures: The appearance of a new-encounter diagnosis of RVO within 21 days of the mRNA COVID-19 vaccination was the primary outcome. Historical comparison cohorts of patients receiving influenza and Tdap vaccinations allowed for evaluation of the RRs for RVO. Results: Of 3 108 829 patients (mean [SD] age at vaccination, 50.7 [20.4] years; 56.4% women) who received the mRNA COVID-19 vaccine, 104 (0.003%; 95% CI, 0.003%-0.004%) patients had a new diagnosis of RVO within 21 days of vaccination. After propensity score matching, the RR for new RVO diagnosis after the first dose of COVID-19 vaccination was not significantly different from that after influenza (RR, 0.74; 95% CI, 0.54-1.01) or Tdap (RR, 0.78; 95% CI, 0.44-1.38) vaccinations, but was greater when compared with the second dose of the COVID-19 vaccination (RR, 2.25; 95% CI, 1.33-3.81). Conclusions and Relevance: The findings of this study suggest that RVO diagnosed acutely after mRNA COVID-19 vaccination occurs extremely rarely at rates similar to those of 2 different historically used vaccinations, the influenza and Tdap vaccines. No evidence suggesting an association between the mRNA COVID-19 vaccination and newly diagnosed RVO was found.

Assessing the relationship between operationally defined zero-dose communities and access to selected primary healthcare services for children and pregnant women in emergency settings.

In this study the authors examine the relationship between "zero-dose" communities and access to healthcare services. This was done by first ensuring the first dose of the Diphtheria Tetanus and Pertussis vaccine was a better measure of zero-dose communities than the measles-containing vaccine. Once ensured, it was used to examine the association with access to primary healthcare services for children and pregnant women in the Democratic Republic of Congo, Afghanistan, and Bangladesh. These services were divided into: a) unscheduled healthcare services such as birth assistance as well as seeking care and treatment for diarrheal diseases and cough/fever episodes and b) other scheduled health services such as antenatal care visits and vitamin A supplementation. Using recent Demographic Health Survey data (2014: Democratic Republic of Congo, 2015: Afghanistan, 2018: Bangladesh), data was analyzed via Chi Squared analysis or Fischer's Exact Test. If significant, a linear regression analysis was performed to examine if the association was linear. While the linear relationship observed between children who had received the first dose of the Diphtheria Tetanus and Pertussis vaccine (the reverse to zero-dose communities) and coverage of other vaccines was expected, the results of the regression analysis depicted an unexpected split in behavior. For scheduled and birth assistance health services, a linear relationship was generally observed. For unscheduled services associated with illness treatments, this was not the case. While it does not appear that the first dose of the Diphtheria Tetanus and Pertussis vaccine can be used to predict (at least in a linear manner) access to some primary (particularly illness treatment) healthcare services in emergency/ humanitarian settings, it can serve as an indirect measure of health services not associated with the treatment of childhood infections such as antenatal care, skilled birth assistance, and to a lesser degree even vitamin A supplementation.

Tdap Booster Vaccination for Adults: Real-World Adherence to Current Recommendations in Italy and Evaluation of Two Alternative Strategies.

BACKGROUND: While the effectiveness of tetanus-diphtheria-pertussis childhood immunization programs is unquestionable, the actual need for a periodic boosting vaccination in adults is controversial. In Italy, the Ministry of Health recommends a Tdap booster vaccination every 10 years. The aim of this study is to assess the real-world adherence of Italian regional healthcare services to national recommendations and to evaluate two alternative strategies. METHODS: Annual Tdap vaccine requirements by the 21 Italian regions were retrieved from related tender announcements, and regional and national vaccination coverage rates (VCRs) were estimated for three scenarios, namely the currently recommended 10-year booster vaccination, a single booster shot at age 50 and at age 65. RESULTS: In Scenario 1, no region reached a VCR > 30%, and the national VCR was 10.6%; in Scenario 2, five regions achieved the optimal vaccination coverage of ≥95%, but the vast majority continued to have inadequate VCRs, with a national VCR of 54.4%; in Scenario 3, five regions reached VCRs exceeding 100%, with VCRs from other regions significantly improving and a national VCR of 74.8%. CONCLUSIONS: A substantial lack of adherence by Italian regional healthcare services to current national recommendations on tetanus-diphtheria-pertussis adult vaccination was shown. Scenario 3 is the most feasible, i.e., a single booster shot at age 65, possibly administrable along with other already-recommended, age-specific vaccines.