Meningococcal B vaccination coverage among older adolescents in the United States

BackgroundSerogroup B meningococcal (MenB) vaccination recommendations for adolescents in the United States (US) include routine vaccination for all individuals at increased risk and vaccination for individuals not at increased risk aged 16–23 years (preferred age 16–18 years) based on shared clinical decision-making. The two licensed MenB vaccines require administration of ≥2 doses.MethodsThis cross-sectional study analyzed 2017–2018 National Immunization Survey-Teen (NIS-Teen) data to evaluate ≥1 dose and ≥2 dose MenB vaccination coverage among adolescents aged 17 years. Multivariable logistic regression was used to further evaluate determinants of MenB vaccination.ResultsNationally, MenB vaccination coverage among 17-year-olds increased from 14.5% in 2017 to 17.2% in 2018 for ≥1 dose and from 6.3% to 8.4% for ≥2 doses. MenB vaccination coverage (2017–2018) was the lowest in the South (≥1 dose: 14.6%; ≥2 doses: 6.3%) and highest in the Northeast region (18.3% and 9.3%), with variation observed by census division. Adolescents were more likely to have received ≥1 dose of MenB vaccine if they had any Medicaid insurance (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.32–2.39) or had received human papillomavirus (OR, 1.94; 95% CI, 1.41–2.67) or meningococcal A, C, W, and Y (OR, 4.03; 95% CI, 2.92–5.56) vaccinations.ConclusionsMenB first-dose coverage in the US is low, and even lower for a second dose, with regional variation. Being up to date with other routinely administered vaccines increased the likelihood of receiving MenB vaccination.     

Factors associated with the immune response to hepatitis A vaccination in HIV-infected patients in the era of highly active antiretroviral therapy

Introduction

HIV seropositivity is considered a risk factor for complications in hepatitis A virus (HAV) infection. HAV vaccination schedules are widely implemented in HIV-infected patients, but the immune response remains impaired.

Methods

We analysed the response to vaccination (antiHAV titres ≥20 IU/l) in 282 HIV-infected patients included in a standard (1440 Elisa Units (EU) at 0, 6 months) or rapidly accelerated schedule (720 EU at 0, 7, 21 days and 6 months) between 1997 and 2009. Factors associated with the response to vaccination were analysed using logistic regression.

Results

The overall response rate was 73.4%. Male sex (OR: 0.16, 95% CI 0.05–0.51) and hepatitis C virus co-infection (OR: 0.30, 95% CI 0.14–0.74) were associated with a lower probability of response. Protective antibody response was associated with a higher CD4/CD8 ratio (OR: 3.69, 95% CI 1.3–10.5) and having received two doses of standard schedule (compared with patients receiving only one dose of the same schedule) (OR: 2.51, 95% CI 1.22–5.15). Three doses of the rapidly accelerated schedule were not more effective than a single dose of 1440 EU (OR: 1.32, 95% CI 0.48–3.63).

Conclusion

The low responses observed in patients receiving a single dose suggest the need to emphasize adhesion to vaccination protocols to avoid failure. The CD4/CD8 ratio may be considered as an immune status marker which could help to better choose the moment of vaccination. Our findings underscore the importance of identifying strategies that optimize the timing and effectiveness of hepatitis A vaccination in HIV-infected patients and of the need for further studies on individual factors such as sex and hepatitis C co-infection that may affect the response to vaccination. Likewise, the sub-optimal effectiveness of three doses of 720 EU in the rapidly accelerated schedule, if confirmed in future studies, might lead to a revision of the current schedule recommended for HIV-infected travellers.     

Risk factors of ICU or high dependency requirements amongst hospitalized pediatric pertussis cases: A 10 year retrospective series,Singapore

IntroductionPertussis causes the highest complication rates and deaths in the infant group. Our study explored risk factors for ICU/high dependency (HD) admissions and intubation/non-invasive ventilation (NIV).MethodsA retrospective review of pertussis admissions over 10 years from 2007 to 2016 was done at KK Women's and Children's Hospital, Singapore. To understand risk factors for severe pertussis infection, we compared cases requiring ICU/HD care with controls admitted to the general ward. Risk factors for intubation/NIV were also studied. Vaccine efficacy for protection against ICU/HD admission or intubation/NIV was also calculated.ResultsThere were 200 pertussis patients with a median age of 2.75 months. Sixty-one % were ≤3 months and 14.5% were <6 weeks old. Majority of patients (77%) had no prior pertussis vaccination. After removing 3 patients with missing vaccination records, 20 cases were compared with 177 controls. On univariate analysis, risk factors for ICU/HD admission comprised: Age ≤3 months, contact history, underlying co-morbidity, prematurity, absent DTaP vaccination, lymphocytosis, hyperleukocytosis (wbc ≥50 × 10⁹/L), thrombocytosis (platelet ≥500 × 10⁹/L), and pneumonia. Multivariate analysis revealed that age ≤3 months (OR 40, 95% CI 4.57–1111.11, p = .007), co-morbidity (OR 8.46 (95% CI 1.47–56.89, p = .019), pneumonia (OR 18.08, 95% CI 3.22–132.15, p = .002), white cell count (OR 1.07, 95% CI 1.01–1.14, p = .023) and cyanosis (OR 5.09, 95% CI 1.31–24.71, p = .026) were risk factors for ICU/HD admission. Prior DTaP vaccination had a vaccine effectiveness of 86.5% in preventing ICU/HD admission and 82.1% in preventing intubation/NIV.ConclusionsAs the majority of pertussis patients were infants ≤3 months old who are at high risk for ICU/HD admission and intubation/NIV, prevention is key to reducing pertussis morbidity. Even though not statistically significant, DTaP vaccination had a role in preventing ICU/HD admission and intubation/NIV.     

Pertussis and influenza immunisation coverage of pregnant women in New Zealand

BackgroundImmunisation is an important public health policy and measuring coverage is imperative to identify gaps and monitor trends. New Zealand (NZ), like many countries, does not routinely publish coverage of immunisations given during pregnancy. Therefore, this study examined pregnancy immunisation coverage of all pregnant NZ women between 2013 and 2018, and what factors affected uptake.MethodsA retrospective cohort study of pregnant women who delivered between 2013 and 2018 was undertaken using administrative datasets. Maternity and immunisation data were linked to determine coverage of pertussis and influenza vaccinations in pregnancy. Generalised estimating equations were used to estimate the odds of receiving a vaccination during pregnancy.ResultsFrom 2013 to 2018 data were available for 323,622 pregnant women, of whom 21.7% received maternal influenza immunisations and 25.7% maternal pertussis immunisations. Coverage for both vaccines increased over time, pertussis increased from 10.2% to 43.6% and influenza from 11.2% to 30.8%. The odds of being vaccinated, with either vaccine, during pregnancy increased with increasing age and decreasing deprivation. Compared to NZ European or Other women, Māori and Pacific women had lower odds of receiving a maternal pertussis (OR:0.55, 95% CI: 0.54, 0.57; OR:0.60, 95% CI: 0.58, 0.62, respectively) and influenza (OR: 0.69, 95% CI: 0.67, 0.71; OR:0.90, 95% CI: 0.87, 0.94, respectively) immunisations during pregnancy. Women were also more likely to be vaccinated against pertussis if they received antenatal care from a General Practitioner or Obstetrician compared to a Midwife. A similar pattern was seen for influenza vaccination.ConclusionGaps in maternal coverage for pertussis and influenza exist and work is needed to reduce immunisation inequities.     

Effectiveness of maternal pertussis vaccination in preventing infection and disease in infants: The NSW Public Health Network case-control study

BackgroundInfants are at the highest risk of severe complications – including death – as a result of pertussis infection. Controlling pertussis in this group has been challenging, particularly in those too young to be vaccinated. Following revised national recommendations in March 2015, the state of New South Wales, Australia, introduced a funded maternal vaccination campaign at 28 – 32 weeks of gestation using a 3-component tetanus-diphtheria-acellular pertussis vaccine (dTpa; Boostrix, GSK). This study aimed to assess the effectiveness of maternal vaccination and add to the growing body of evidence for this strategy.MethodsA 1:1 matched case-control study was conducted between 16 August 2015 and 17 August 2016. Cases were laboratory or doctor notified, laboratory confirmed (nucleic acid testing or culture) and aged <6 months at onset. Each control infant was randomly selected from public hospital births in the same geographical area in the period up to 3 days before and after the case’s birthdate. Odds ratios (OR) were calculated using conditional logistic regression. Vaccine effectiveness (VE) was calculated as 1 – OR.FindingsIn total, 117 cases and 117 controls were recruited. The overall VE estimate was non-significantly protective for infants <6 months old (VE 39%, 95% CI −12 to 66%). Higher VE was observed for infants <3 months old (VE 69%, 95% CI 13–89%) and against hospitalisation (VE 94%, 95% CI 59–99%).InterpretationMaternal pertussis vaccination with a 3-component acellular vaccine was found to be highly effective at preventing severe disease in infants, but was less effective at preventing disease which did not require hospitalisation. The overall VE reported in this study was lower than in prior studies and suggests that maternal vaccination, while an effective strategy at preventing severe pertussis, is less effective at protecting against infection or mild disease.     

A multisite study of pertussis vaccine effectiveness by time since last vaccine dose from three Canadian provinces: A Canadian Immunization Research Network study

BackgroundPertussis remains poorly controlled relative to other diseases targeted by childhood vaccination programs. We combined estimates from four population-based studies of pertussis vaccine effectiveness (VE) in three Canadian provinces using a meta-analytic approach to improve precision and explore regional variation in VE and durability of protection.MethodsStudies were conducted in Alberta, Manitoba, and Ontario over periods ranging from 1996 to 2015. Adjusted log odds ratios (OR; VE = 100*[1-OR]) of the effect of vaccination on pertussis risk were estimated by time since last vaccination in each study and pooled using DerSimonian and Laird random-effects models. We used the I² statistic to estimate between-study heterogeneity and assessed methodological and clinical heterogeneity through subgroup analyses of study design and age.ResultsData on 3,270 pertussis cases and 23,863 controls were available. Pertussis VE declined from 86% (95% CI 79%-90%, I² = 81.5%) at < 1 year since last vaccination to 51% (11%-74%, I² = 80.9%) by ≥ 8 years. Effect estimates were the most heterogeneous in the least and most elapsed time periods since last vaccine dose. This was attributable mostly to variation between provinces in the distribution of age groups and number of vaccine doses received within time periods, as well as study design and small numbers in the most elapsed time period.Interpretation: Consistent trends of decreasing pertussis VE with increasing time since last vaccination across three Canadian provinces indicate the need for immunization schedules and vaccine development to optimize protection for all individuals, especially for adolescents and young adults at greatest risk of infection.     

Protective effect of COVID-19 vaccination against long COVID syndrome: A systematic review and meta-analysis

BackgroundThe relationship between coronavirus disease 2019 (COVID-19) vaccination and long COVID has not been firmly established. We conducted a systematic review and meta-analysis to evaluate the association between COVID-19 vaccination and long COVID.MethodsPubMed and EMBASE databases were searched on September 2022 without language restrictions (CRD42022360399) to identify prospective trials and observational studies comparing patients with and without vaccination before severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. We also included studies reporting symptomatic changes of ongoing long COVID following vaccination among those with a history of SARS-CoV-2 infection. Odds ratios (ORs) for each outcome were synthesized using a random-effects model. Symptomatic changes after vaccination were synthesized by a one-group meta-analysis.ResultsSix observational studies involving 536,291 unvaccinated and 84,603 vaccinated (before SARS-CoV-2 infection) patients (mean age, 41.2–66.6; female, 9.0–67.3%) and six observational studies involving 8,199 long COVID patients (mean age, 40.0 to 53.5; female, 22.2–85.9%) who received vaccination after SARS-CoV-2 infection were included. Two-dose vaccination was associated with a lower risk of long COVID compared to no vaccination (OR, 0.64; 95% confidence interval [CI], 0.45–0.92) and one-dose vaccination (OR, 0.60; 95% CI, 0.43–0.83). Two-dose vaccination compared to no vaccination was associated with a lower risk of persistent fatigue (OR, 0.62; 95% CI, 0.41–0.93) and pulmonary disorder (OR, 0.50; 95% CI, 0.47–0.52). Among those with ongoing long COVID symptoms, 54.4% (95% CI, 34.3–73.1%) did not report symptomatic changes following vaccination, while 20.3% (95% CI, 8.1–42.4%) experienced symptomatic improvement after two weeks to six months of COVID-19 vaccination.ConclusionsCOVID-19 vaccination before SARS-CoV-2 infection was associated with a lower risk of long COVID, while most of those with ongoing long COVID did not experience symptomatic changes following vaccination.     

What predicts postpartum pertussis booster vaccination? A controlled intervention trial

Background‘Cocooning’ aims to protect susceptible infants from pertussis via caregiver vaccination. Control trials evaluating educational interventions to promote cocooning are lacking. We evaluated the role of message-framing vs. standard health information in promoting pertussis vaccination.MethodsWe recruited postpartum women from a maternity hospital in Sydney, Australia (November 2010–July 2012). Participants self-completed a pertussis knowledge and attitudes questionnaire. We then assigned pertussis-susceptible (no pertussis vaccine ≤10 years) participants to receive a gain-framed, loss-framed pamphlet or control (Government Pertussis factsheet) using weekly sequential block allocation. Next, participants were offered a pertussis vaccine (dTpa) and completed a post-questionnaire on discharge.ResultsA baseline questionnaire was completed for 96.4% (1433/1486) of postpartum women approached. Missing data was excluded (n = 29). Next, participants (1404) were screened for vaccine status: 324 (23%) reported prior pertussis booster vaccine receipt, leaving 1080 participants requiring vaccination. Among susceptible mothers, 70% (754/1080) were vaccinated post-intervention. Rates were similar between ‘gain’, ‘loss’ or ‘control’ pamphlets (69.1% vs. 71.8% vs. 68.8%; p = 0.62). Intention to be vaccinated (OR 2.46, p < 0.001; 95% CI: 1.69–3.58), perceived vaccine benefits (OR: 1.61, p < 0.001; 95% CI: 1.25–2.15) and having received a vaccine recommendation (OR 1.68; p = 0.025; 95% CI: 1.07–2.65) were independent predictors of vaccine uptake. At discharge, overall pertussis vaccine coverage had increased from 23% to 77% among women screened (1078/1404).ConclusionA cocooning strategy for pertussis vaccination can be highly effective when partially implemented within maternity hospitals, with information accompanied by a funded vaccine. Mothers were highly receptive to vaccination in the postnatal ward: facts about pertussis were as effective as message-framing in promoting a high uptake of 70%. Perceived vaccine benefits, intentions and vaccine recommendation were important predictors of uptake. Our intervention trial increased the existing pertussis vaccine coverage of 23–77%.     

Psychosocial determinants of pertussis and influenza vaccine uptake in pregnant women: A prospective study

ObjectiveTo identify the psychosocial factors influencing women’s uptake and willingness to receive pertussis and influenza vaccine during pregnancy.MethodsThe study population comprised 1364 healthy nulliparous pregnant women who participated in a prospective cohort study at two obstetric hospitals in South Australia between 2015 and 2017. Information on women's vaccination status, sociodemographic, lifestyle and psychological state were collected at 9–16 weeks’ gestation and medical case notes were checked post-delivery to verify the reported vaccination status. Poisson regression models were used to estimate the crude and adjusted prevalence ratios (aPRs) to identify psychosocial factors influencing uptake of vaccination during pregnancy.ResultsWillingness to receive the recommended maternal vaccines was high (90%). Overall, 79% and 48% received maternal pertussis and influenza vaccines respectively. There was no evidence to support the influence of psychosocial factors on women’s willingness to receive immunization during pregnancy. High levels of anxiety (aPR 0.98, 95% CI: 0.87–1.09) was not associated with uptake of maternal pertussis vaccine. However, elevated depressive symptoms (aPR 1.14, 95% CI: 1.00–1.30) and very high-perceived stress during pregnancy were significantly associated with receipt of pertussis vaccination (aPR 0.87; 95% CI 0.76–0.99). Women with mild depressive symptoms (aPR 1.21, 95% CI 1.00–1.44) and mild anxiety symptoms (aPR 1.21, 95% CI: 0.99–1.48) were more likely to receive influenza vaccine during pregnancy (aPR 1.27, 95% CI: 1.08–1.49). A history of major depressive disorder was independently associated with receipt of pertussis (aPR 1.16, 95% CI 1.06–1.26) and influenza vaccination during pregnancy (aPR 1.32; 95% CI 1.14–1.58).ConclusionRegardless of psychosocial factors, most women reported a positive willingness to receive the recommended vaccinations during pregnancy. However, psychosocial factors influenced the uptake of pertussis and influenza vaccines during pregnancy. Psychosocial factors should be taken into consideration in designing interventions and implementation of maternal pertussis and influenza immunization programs.     

Safety of maternal pertussis vaccination on pregnancy and birth outcomes: A prospective cohort study

ObjectiveTo evaluate the safety of maternal pertussis vaccination on pregnancy and birth outcomes.MethodsThe study population comprised 1272 healthy nulliparous pregnant women who participated in Screening Tests to identify poor Outcomes in Pregnancy (STOP) study at two obstetric hospitals in South Australia between 2015 and 2018. Participants were followed prospectively, with vaccination (confirmed by medical records), extensive amounts of pregnancy and birth outcome data collected by research midwives. Adjusted relative risks (aRRs) and hazard ratios (aHRs) were estimated accounting for time-varying vaccine exposure and the temporal nature of each outcome.ResultsOf the 1272 women included in this study, 80.1% (n = 1019) received maternal pertussis vaccination. Vaccinated women had an average 0.22 weeks (95% CI 0.001, 0.44) longer gestation at delivery compared to unvaccinated women. Maternal pertussis vaccination was not associated with chorioamnionitis (aRR 0.71, 95% CI 0.27,1.82), gestational hypertension (aHR 1.24, 95% CI, 0.66, 2.30), preeclampsia (aHR 0.75, 95% CI 0.47, 1.18) nor preterm birth (aHR 0.99, 95% CI 0.47, 2.07). Neither risk of low birth weight (aHR 0.72, 95% CI 0.41, 1.27) nor small for gestational age infants (aHR 0.67,95% CI 0.29, 1.55) were increased following maternal pertussis vaccination. No associations between pertussis vaccination during pregnancy and adverse birth outcomes including admission to the neonatal care unit, low Apgar scores, and mechanical ventilation were observed. Results were not materially changed after adjustment for maternal influenza vaccination.ConclusionOur study provides reassuring evidence of the safety of maternal pertussis vaccination with no increased risk of adverse pregnancy and birth outcomes. These findings support recommendations for pertussis vaccination during pregnancy to prevent morbidity and mortality associated with early-infant pertussis disease.     

Does consecutive influenza vaccination reduce protection against influenza: A systematic review and meta-analysis

IntroductionVaccination against influenza on an annual basis is widely recommended, yet recent studies suggest consecutive vaccination may reduce vaccine effectiveness (VE).PurposeTo assess whether when examining the entirety of existing data consecutive influenza vaccination reduces VE compared to current season influenza vaccination.Data sourcesMEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to April 26, 2017; citations of included studies.Study selectionRandomized, controlled trials (RCTs) and observational studies of children, adults and/or the elderly that reported laboratory-confirmed influenza infection over 2 or more consecutive influenza seasons were eligible.Data extractionData related to study characteristics, participant demographics, cases of influenza infection by vaccination group and risk of bias assessment was extracted in duplicate.Data synthesisFive RCTs involving 11,987 participants did not show a significant reduction in VE when participants vaccinated in two consecutive seasons (VE 71%, 95% CI 62–78%) were compared to those vaccinated in the current season (VE 58%, 95% CI 48–66%) (odds ratio [OR] 0.88, 95% CI 0.62–1.26, p = 0.49, I² = 39%). Twenty-eight observational studies involving 28,627 participants also did not show a reduction (VE for two consecutive seasons 41%, 95% CI 30–51% compared to VE for current season 47%, 95% CI 39–54%; OR 1.14, 95% CI 0.98–1.32, p = 0.09, I² = 63%). Results from subgroup analyses by influenza type/subtype, vaccine type, age, vaccine match and co-morbidity support these findings; however, dose–response results were inconsistent. Certainty in the evidence was assessed to be very low due to unexplained heterogeneity and imprecision.LimitationsThe inclusion of studies with relatively small sample sizes and low event rates contributed to the imprecision of summary VE and OR estimates, which were based on unadjusted data.ConclusionAvailable evidence does not support a reduction in VE with consecutive influenza vaccination, but the possibility of reduced effectiveness cannot be ruled out due to very low certainty in this evidence.Funding sourceCIHR Foundation Grant (PROSPERO: CRD42017059893).     

Effectiveness of acellular pertussis vaccine and evolution of pertussis incidence in the community of Madrid from 1998 to 2015

IntroductionPertussis is a communicable disease that primarily affects infants. Vaccination has led to an important reduction in the incidence of the disease, however, resurgence of the disease has been observed. This study aimed to analyze the incidence of pertussis and assess the vaccination effectiveness (VE) of different schedules of acellular pertussis vaccination in the community of Madrid.MethodsPertussis cases notified to the Mandatory Disease Reporting System from 1998 to 2015 were analyzed. Five comparison periods were created: 1998–2001 (reference), 2002–2005, 2006–2009, 2010–2012 and 2013–2015. The incidence ratio (IR) between inter-epidemic periods was analyzed using a Poisson regression. VE was calculated using the screening method. Vaccine status data were collected from the vaccine registry.ResultsIn total, 3855 cases were notified. Inter-epidemic periods were observed every 3–4 years. The incidence increased (IR: 5.99, p < 0.05) in the 2013–2015 period, particularly among infants younger than 1 month (IR: 32.41, p < 0.05). Vaccination data were available in 89% of cases. For those receiving the last dose at ≤6-month VE was 89.9% (95% confidence interval (CI): 87.3–92.0) after one year of follow-up, and 85.5% (95% CI: 82.4–88.1) after 11 years of follow-up. For those receiving the last dose at 18-months VE decreased from 98.8% (95% CI: 98.3–99.1) to 85.1% (95% CI: 81.9–87.7) in the same period, and for those receiving the last dose at 4-year VE decreased from 99.6% (95% CI: 99.3–99.7) to 79.3% (95% CI: 74.6–83.1).ConclusionsB. pertussis is circulating in our population, as shown by the epidemic peaks and increased incidence of pertussis in recent years. VE increased with the number of doses and decreased with the follow-up period. The effect of this and other vaccination strategies must be monitored to control the disease.     

Analysis of Tick-borne Encephalitis vaccination coverage and compliance in adults in Switzerland, 2018

BackgroundOverall incidence and geographic range of Tick-borne Encephalitis (TBE), a vaccine preventable infection, have steadily increased in Switzerland over the last 50 years. While fully subsidized vaccination has been recommended in many areas for well over a decade, vaccine coverage and variables associated with vaccination compliance among Swiss adults are poorly understood.MethodsIn 2018 we conducted a national, cross-sectional survey of vaccination cards evaluating TBE vaccination coverage and compliance among adults (18-79) in Switzerland.ResultsNationwide TBE vaccination coverage was 41.7% (range 14.3% to 60.3%) for 1 dose and 32.9% (range 8.4% to 50.4%) for a complete primary series (3 doses). There was a significant correlation between average disease incidence by canton (2009-2018) and vaccine coverage at both 1 and 3 doses. Of the overall population, 9.5% had received at least one TBE booster vaccination with large regional coverage variation. We estimated that 23% of adults in Switzerland would be protected from infection based on their vaccination history and 135 (95% CI: 112-162) TBE cases were prevented in 2018. Individuals reporting previous experience with tick-associated health problems, those frequently in nature or those with “high” perceived risk of contracting TBE, were significantly more likely to have received at least one vaccine dose, indicating a positive impact of awareness on vaccination compliance. We also calculated a TBE incidence rate of 6.83/100,000 among the unvaccinated adult population in Switzerland and estimated vaccine effectiveness at 91.5% (95% CI: 90.9-92.0%).ConclusionsThese findings provide an important reference for TBE vaccination levels in Switzerland and further suggest that public health interventions promoting knowledge of TBE health impacts and risk factors may be beneficial in improving TBE vaccination coverage but should be tailored to account for heterogeneity in vaccine uptake.     

Effectiveness of parental cocooning as a vaccination strategy to prevent pertussis infection in infants: A case-control study

BackgroundDuring a pertussis epidemic in 2009, the Department of Health, Victoria, Australia, implemented a cocoon program offering parents of new babies a funded-dose of pertussis-containing vaccine. We assessed vaccine effectiveness (VE) of the program in reducing pertussis infection in infants.MethodsUsing a matched case-control design, infants aged <12 months that were notified with pertussis between 1 January 2010 and 31 December 2011, and born during the time that the cocoon program was in place, were identified. Controls were matched by area of residence and date of birth. Telephone interviews we conducted to ascertain parents’ vaccination status, and if vaccinated, timing of vaccination receipt relative to the birth of their baby. Odds ratios (ORs) were calculated for the association between vaccination and pertussis infection, with VE calculated as (1 – OR) × 100%.ResultsThe study recruited 215 cases and 240 controls (response rates 67% and 25% of eligible participants, respectively). Vaccination of both parents after delivery of the infant and ≥28 days prior to illness onset reduced pertussis infection by 77% (Vaccine Effectiveness [VE] = 77% (confidence interval [95% CI], 18–93%). After adjusting for maternal education, presence of a sibling within the household, and the infants’ primary course vaccination status, the adjusted VE was 64% (95% CI, −58–92%).ConclusionsAlthough not reaching statistical significance, our results demonstrated that cocoon immunisation – where both parents are vaccinated in the post-partum period – may offer some protection again infant pertussis infection. Cocoon immunisation could be considered in circumstances where antenatal vaccination of the mother has not occurred.     

Hepatitis B vaccination coverage in healthcare workers in Gauteng Province, South Africa

Hepatitis B (HB) virus (HBV) is highly endemic and HBV infection is a major public health problem in sub-Saharan Africa. Percutaneous/parenteral transmission is an important mode of spread of HBV in the healthcare setting, thus healthcare workers (HCWs) and their patients are at risk for acquiring HBV infections. This study was conducted on three HCW populations in Gauteng Province during 2009, in order to (1) determine HB vaccination coverage of HCWs, and (2) investigate demographic predictors of vaccination uptake. Being a doctor was a statistically significant predictor of vaccination uptake (odds ratio [OR]: 3.2; 95% confidence interval [CI]: 1.48-6.72; p-value: 0.003), while working in the private sector was also statistically significantly associated with vaccination uptake (OR: 1.73; 95% CI: 1.01-2.98; chi-square p-value: 0.035). The majority (67.9% [491/723]) of HCWs had received at least 1 dose of vaccine, but where data on number of doses was available, only 19.9% (94/472) were fully vaccinated. In conclusion, there is a need to increase HB vaccination uptake in Gauteng HCWs through a policy that is properly implemented and routinely monitored and evaluated, and this policy must ensure that all three doses of vaccine are administered.     

Age-specific effectiveness following each dose of acellular pertussis vaccine among infants and children in New Zealand

BackgroundThough it is believed the switch from whole cell to acellular pertussis vaccine has contributed to the resurgence of pertussis disease, few studies have evaluated vaccine effectiveness (VE) and duration of protection provided by an acellular vaccine schedule including three primary doses but no toddler-age dose. We assessed this schedule in New Zealand (NZ), a setting with historically high rates of pertussis disease, and low but recently improved immunisation coverage. We further evaluated protection following the preschool-age booster dose.MethodsWe performed a nested case-control study using national-level healthcare data. Hospitalised and non-hospitalised pertussis was detected among children 6 weeks to 7 years of age between January 2006 and December 2013. The NZ National Immunisation Register provided vaccination status for cases and controls. Conditional logistic regression was used to calculate dose-specific VE with duration of immunity examined by stratifying VE into ages aligned with the immunisation schedule.ResultsVE against pertussis hospitalisation was 93% (95% confidence interval [CI]: 87, 96) following three doses among infants aged 5–11 months who received three compared to zero doses. This protection was sustained through children’s fourth birthdays (VE ⩾ 91%). VE against non-hospitalised pertussis was also sustained after three doses, from 86% (95% CI: 80, 90) among 5–11 month olds to 84% (95% CI: 80, 88) among 3-year-olds. Following the first booster dose at 4 years of age, the protective VE of 93% (95% CI: 90, 95) among 4-year-olds continued through 7 years of age (VE ⩾ 91%).ConclusionsWe found a high level of protection with no reduction in VE following both the primary course and the first booster dose. These findings support a 3-dose primary course of acellular vaccine with no booster dose until 4 years of age.     

Acellular pertussis vaccine effectiveness and waning immunity in Alberta,Canada: 2010–2015, a Canadian Immunization Research Network (CIRN) study

BackgroundPertussis is still frequently reported in Canada. In Alberta, pertussis incidence ranged from 1.8 to 20.5 cases per 100,000 persons for 2004–2015. Most cases occurred in those aged <15 years. In Alberta, acellular formulations replaced whole-cell in 1997. We investigated pertussis vaccine effectiveness (VE) using a test-negative design (TND) study.MethodsWe included all persons who had a real-time PCR laboratory test for Bordetella pertussis between January 1, 2010 and August 31, 2015, in the province of Alberta, Canada. Vaccination history was obtained from Alberta’s immunization repository. Vaccination status was classified as complete, incomplete, or unvaccinated, based on the province’s vaccination schedule. Persons who had received ≥one dose of whole cell vaccine were excluded from analysis. Multivariable logistic regression models were used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (95% CI) for pertussis infection by time since last vaccination. We adjusted for vaccination status, age, sex, neighbourhood income, urban/rural status, and the presence of a co-morbid condition. VE was calculated as [(1 − aOR) * 100].ResultsOf the 12,149 tests available, 936 (7.7%) were positive for Bordetella pertussis. Among the full cohort, VE was 90% (95% CI 87–92%) at 1 year, 81% (95% CI 77–85%) at 1–3 years, 76% (95% CI 68–82%) at 4–7 years, and 37% (95% CI 11–56%) at 8 or more years since a last dose of acellular pertussis vaccine.ConclusionsPertussis VE was highest in the first year after vaccination, then declined noticeably as years since a last vaccination increased. Our results suggest that a large number of adolescents and adults are susceptible to infection with Bordetella pertussis. Regular boosters throughout childhood, adolescence, and during pregnancy may be needed.     

Changes in COVID-19 vaccine acceptance rate among recovered critically Ill patients: A 12-month follow-up study

IntroductionWe surveyed a cohort of patients who recovered from severe SARS-CoV-2 infection to determine the COVID-19 vaccination rate. We also compared the willingness to accept COVID-19 vaccine before and after its availability to assess changes in perception and attitude towards vaccination.Materials and MethodsRecovered patients with severe hypoxemic respiratory failure from SARS-CoV-2 infection treated in the ICU at Grady Memorial Hospital, Atlanta, Georgia between April 1, 2020, and June 30, 2020 were followed up over a 1-year period to assess vaccine acceptability and acceptance rates, and changes in perception towards COVID-19 vaccination before and after vaccine availability.ResultsA total of 98 and 93 patients completed the initial and follow up surveys respectively. During the initial survey, 41% of the patients intended to receive vaccination, 46% responded they would not accept a vaccine against COVID-19 even if it were proven to be ‘safe and effective ‘and 13% undecided. During the follow up survey, 44% of the study cohort had received at least one dose of a COVID-19 vaccine. Major reasons provided by respondents for not accepting COVID-19 vaccine were lack of trust in the effectiveness of the vaccine, pharmaceutical companies, government, vaccine technology, fear of side effects and perceived immunity against COVID-19. Respondents were more likely to be vaccinated if recommended by their physicians (OR 6.4, 95% CI 2.8–8.3), employers (OR 2.5, 95% CI 1.9–5.8), and family and friends (OR 1.6, 95% CI 1.1–4.5).ConclusionWe found a suboptimal COVID-19 vaccination rate in a cohort of patients who recovered from severe infection. COVID-19 vaccine information and recommendation by healthcare providers, employers, and family and friends may improve vaccination uptake.     

Uptake of HPV Vaccine among young adults with disabilities, 2011 to 2018

IntroductionLittle is known about human papillomavirus (HPV) vaccine uptake among young adults with disabilities (YAWD), despite this population having a higher risk of HPV infection and related cancers compared to the general population.ObjectiveTo compare the prevalence of HPV vaccination among young adults with disabilities to young adults without disabilities. We hypothesized that YAWD would have a lower prevalence of HPV vaccination than the general population.MethodsThis cross-sectional study used data for the years 2011 to 2018 of the National Health Interview Survey. Our analysis included 14,577 people (weighted n = 34,420,024) aged 18 to 26 years. Univariate and multivariable logistic models were used to estimate the role of disability on HPV vaccination uptake among young adults and to identify potential factors associated with HPV vaccination among YAWD.ResultsThe proportion of female and male YAWD with HPV vaccination was similar to those without disabilities, regardless of sex (Female Adjusted Odds Ratio (OR): 1.16; 95% Confidence Interval (CI): 0.91 to 1.48; Male Adjusted OR: 1.05; 95% CI: 0.69 to 1.60). Among female and male YAWD, the proportion with HPV vaccination was 56.1% and 28.5%, respectively. Other factors significantly associated with HPV vaccination among YAWD included age, country of birth, healthcare utilization, and insurance status.ConclusionsHPV vaccination among YAWD did not differ significantly from those without disabilities; however, the prevalence of HPV vaccination among young adult males and females remains significantly below national goals. Connecting young adults, specifically male YAWD, to the healthcare system is of utmost importance to improve HPV vaccination uptake.     

Estimates of pertussis vaccine effectiveness in United States air force pediatric dependents

BackgroundPertussis vaccination compliance is critical for reduction in the prevalence of disease; however, the current acellular pertussis vaccine may not provide sufficient protection from infection. This study examined acellular pertussis vaccine effectiveness (VE) for Air Force dependents less than 12 years of age.MethodsWe conducted a case-control study among Air Force pediatric dependents from 2011 to 2013, comparing cases with positive pertussis test results to controls who received the same lab tests with a negative result. Our study population was categorized by age group and vaccination status based on the Centers for Disease Control and Prevention recommended pertussis vaccination schedule. VE was calculated with respect to vaccination status and pertussis lab results.ResultsWe compared 27 pertussis laboratory positive cases with 974 pertussis laboratory negative controls, 2 months to <12 years old. Comparing completely vaccinated to non-vaccinated patients, the overall VE was 78.3% (95% confidence interval (CI): 48.6, 90.8; p < 0.001). VE was highest among those 15 months to <6 years old: 97.6% (95% CI: 78.5, 99.7; p < 0.001). Children 6 to <12 years old had the lowest VE: 48.5% (95% CI: −74.0, 84.7; p = 0.28). Comparing partially vaccinated patients to nonvaccinated patients yielded 64.2% (95% CI: −7.2, 88.1; p = 0.06) overall VE.ConclusionsAcellular pertussis vaccination was effective at preventing laboratory confirmed pertussis among our Air Force pediatric dependent population, with highest protection among completely vaccinated, young children. Older children received the lowest amount of protection. Partial vaccination had near significant protection. Our overall calculated pertussis VE corroborates other pertussis VE studies looking at similar age groups.