Vaccine Series Completion Research Articles

COVID-19 vaccination program at a student-run free clinic: A descriptive study

People historically excluded from receiving medical care in the United States, in addition to being at greater risk for SARS-CoV-2 infection, have had slower vaccine uptake due to structural barriers to availability. We present one student-run free clinic’s SARS-CoV-2 vaccination program from January 15 to August 1, 2021, in Nashville, Tennessee. We tracked SARS-CoV-2 vaccine primary series completion among 273 free clinic patients with the help of medical student volunteers, who scheduled appointments and answered vaccine-related questions. We worked with our academic medical center partner to host a single-dose vaccination event at our clinic. We compared vaccine series completion in our clinic to adult vaccine completion in Davidson County, Tennessee on August 1, 2021. Of the 273 free clinic participants, 144 identified as Spanish-speaking (52.7%) and 172 (63%) had at least one qualifying comorbidity per the December 30, 2020, Tennessee COVID-19 Vaccination Plan. As such, 183 (67%) were characterized as vaccine eligible in Phase 1a2, 1b, or 1c. On August 1, 2021, 63.1% of free clinic patients had completed their primary SARS-CoV-2 vaccination series compared with 58.9% of adults in Davidson County, Tennessee (RD 4.2%, 95% CI: −1.5% to 9.9%). Spanish-speaking free clinic patients were most likely to have completed their vaccination series. We describe a framework for a patient-centered vaccination effort to reach individuals traditionally missed by large vaccination campaigns. We highlight structural hurdles experienced by vulnerable populations, including language barriers, lack of technology or reliable internet access, inflexible working schedules, lack of transportation, and vaccine misinformation.

Low human papillomavirus vaccine uptake among women engaged in HIV care in Ontario, Canada

Women living with HIV are at higher risk for human papillomavirus (HPV)-related dysplasia and cancers and thus are prioritized for HPV vaccination. We measured HPV vaccine uptake among women engaged in HIV care in Ontario, Canada, and identified socio-demographic, behavioural, and clinical characteristics associated with HPV vaccination. During annual interviews from 2017 to 2020, women participating in a multi-site, clinical HIV cohort responded to a cross-sectional survey on HPV vaccine knowledge and receipt. We used logistic regression to derive age-adjusted odds ratios and 95% confidence intervals (CI) for factors associated with self-reported vaccine initiation (≥1 dose) or series completion (3 doses). Among 591 women (median age = 48 years; interquartile range = 40–56 years), 13.2% (95%CI = 10.5–15.9%) had received ≥1 dose. Of those vaccinated, 64.6% had received 3 doses. Vaccine initiation (≥1 dose) was significantly higher among women aged 20–29 years at 31.0% but fell to 13.9% in those aged 30–49 years and < 10% in those aged ≥50 years. After age adjustment, vaccine initiation was significantly associated with being employed (vs. unemployed but seeking work), income $40,000–$59,999 (vs. <$20,000), being married/common-law (vs. single), living with children, immigrating to Canada >5 years ago (vs. immigrating ≤5 years ago), never smoking (vs. currently smoking), and being in HIV care longer (per 10 years). Similar factors were identified for series completion (3 doses). HPV vaccine uptake remains low among women living with HIV in our cohort despite regular engagement in care. Recommendations for improving uptake include education of healthcare providers, targeted community outreach, and public funding of HPV vaccination.

Maternal COVID-19 Vaccine May Reduce the Risk of MIS-C in Infants: A Narrative Review.

COVID-19 infection in the pediatric population usually leads to a mild illness; however, a rare but serious complication of MIS-C has been seen in children. MIS-C usually presents 2–4 weeks after COVID-19 infection or exposure, and rare reports have been documented in neonates. Vaccinations for COVID-19 have been approved for children aged 6 months and above in the United States, and recent reports suggest significantly low prevalence and risk of complications of Multi-organ Inflammatory Syndrome (MIS-C) in vaccinated children compared to unvaccinated children. Vaccinations for COVID-19 are safe and recommended during pregnancy and prevent severe maternal morbidity and adverse birth outcomes. Evidence from other vaccine-preventable diseases suggests that through passive transplacental antibody transfer, maternal vaccinations are protective against infections in infants during the first 6 months of life. Various studies have demonstrated that maternal COVID-19 vaccination is associated with the presence of anti-spike protein antibodies in infants, persisting even at 6 months of age. Further, completion of a 2-dose primary mRNA COVID-19 vaccination series during pregnancy is associated with reduced risk for COVID-19–associated hospitalization among infants aged 6 months or less. Therefore, it can be hypothesized that maternal COVID-19 vaccination can reduce the risk of and severity of MIS-C in infants. In this article, we review the literature to support this hypothesis.

Tdap-HPV vaccination bundling in the USA: Trends, predictors, and implications for vaccine series completion

The Centers for Disease Control and Prevention (CDC) promotes taking a ‘bundling approach’ (i.e., administering Tetanus, diphtheria toxoids, and acellular pertussis [Tdap] and human papillomavirus [HPV] vaccines in the same way and on the same day) for adolescent vaccinations. Recent trends and patterns in Tdap-HPV vaccination bundling in the USA remain undocumented. In addition, the implications of bundling Tdap-HPV vaccination for HPV vaccine series completion remain unknown. To address these critical knowledge gaps, we performed a retrospective study using a nationwide sample of privately insured adolescents (Optum's de-identified Clinformatics® Data Mart Database). Tdap-HPV vaccination bundling (per 100 Tdap vaccination encounters) during 2014–2018 was estimated overall, for 50 states, and by adolescents' age, sex, and provider specialties. Survival model estimated the likelihood of series completion among 9–14-year-old adolescents. From 2014 to 2018, 560,806 adolescents received a Tdap vaccine of which 172,604 (30.8%) received the HPV vaccines on the same day. Tdap-HPV vaccination bundling (per 100 Tdap vaccinations) increased nationally, from 22.9 in 2014 to 39.1 in 2018 (Ptrend < 0.001); bundling was lowest in New York and New Jersey. The likelihood of receiving the Tdap and HPV vaccines bundled was higher for young and female adolescents. Adolescents who received their first HPV vaccine bundled with the Tdap vaccine were more likely to complete the series compared to those who received it alone (Hazards Ratio = 1.45; 1.43–1.48). HPV vaccination bundling has increased in recent years in the USA. The increased likelihood of HPV vaccine series completion provides important evidence supporting the adoption of same-day Tdap-HPV vaccine administration in clinical practice to boost HPV vaccination coverage.

Impact of pharmacist motivational interviewing on hepatitis B vaccination in adults with diabetes

BackgroundIn 2011, the Advisory Committee on Immunization Practices recommended hepatitis B (HepB) vaccination for previously unvaccinated adults (aged 19-59 years) with diabetes. Despite these recommendations, vaccination coverage for HepB vaccination for persons with diabetes remains low. ObjectivesThe primary objective was to determine the impact of a community pharmacist-led motivational interviewing (MI) intervention on HepB vaccination initiation among adults with diabetes who were previously unvaccinated against HepB. The secondary objective was to describe HepB vaccination series completion among adults with diabetes who initiated the first dose of a HepB vaccine. MethodsA prospective, nonrandomized, controlled cluster trial was conducted across 58 regional grocery store chain pharmacies: a total of 29 pharmacies in the MI group and 29 pharmacies in the control group. Pharmacy location-level baseline data were collected during a 12-month pre-program period. The MI program was delivered over 10 months. Alerts were generated during prescription processing throughout the study period for eligible patients at each MI pharmacy location. The MI consisted of a face-to-face conversation between the pharmacist and the patient at the time of prescription pick-up. The difference in the primary outcome of HepB vaccination series initiation between patients receiving MI and control patients was assessed using a difference-in-differences analysis. For series completion, patients who initiated the HepB vaccination series were followed up for over 12 months after their first HepB vaccine dose. ResultsThere was a statistically significant 3.711% increase in HepB vaccination when comparing eligible individuals who received the MI intervention (n = 1569) to eligible individuals in the control group (n = 3640). Of the patients in the MI group who initiated HepB vaccination, 40 of 65 patients (61.5%) completed the vaccination series. ConclusionA pharmacist-led MI intervention increased HepB vaccination rates among adult patients with diabetes. Community pharmacists can effectively provide vaccinations that require multiple doses to complete the vaccination series.

Impact of a Multi-Level, Multi-Component, System Intervention on HPV Vaccination in a Federally Qualified Health Center.

Human papillomavirus (HPV) vaccines can significantly reduce the burden of HPV-associated cancers, but remain underutilized. We evaluated a multi-component, system-level intervention to improve HPV vaccination in a large Federally Qualified Health Center (FQHC) that serves a primarily low income Latino population. From January 2015 through March 2017, we evaluated the effectiveness of a multi-component, system-level intervention to improve HPV vaccination rates in eight clinics randomly assigned to study condition (four intervention, four usual care). The intervention included parent reminders for HPV vaccine series completion, provider training, clinic-level audit and feedback, and workflow modifications to reduce missed opportunities for vaccination. Using a difference-in-differences approach, we compared HPV vaccination rates among patients, ages 11 to 17 during a 12-month preintervention period and a 15-month intervention period. Linear mixed models were used to estimate intervention effects on vaccine initiation and completion. The sample included approximately 15,000 adolescents each quarter (range 14,773-15,571; mean age 14 years; 51% female, 88% Latino). A significantly greater quarterly increase in HPV vaccine initiation was observed for intervention compared with usual care clinics (0.75 percentage point greater increase, P &lt; 0.001), corresponding to 114 additional adolescents vaccinated per quarter. The intervention led to a greater increase in HPV vaccine completion rates among boys (0.65 percentage point greater increase, P &lt; 0.001), but not girls. Our system-level intervention was associated with modest improvements in HPV vaccine initiation overall and completion among boys. Study findings have implications for reducing HPV-related cancers in safety net populations.

Effectiveness Associated With Vaccination After COVID-19 Recovery in Preventing Reinfection

The benefit of vaccination for preventing reinfection among individuals who have been previously infected with SARS-CoV-2 is largely unknown. To obtain population-based estimates of the probability of SARS-CoV-2 reinfection and the effectiveness associated with vaccination after recovery from COVID-19. This cohort study used Rhode Island statewide surveillance data from March 1, 2020, to December 9, 2021, on COVID-19 vaccinations, laboratory-confirmed cases, hospitalizations, and fatalities to conduct a population-based, retrospective study during periods when wild type, Alpha, and Delta strains of SARS-CoV-2 were predominant. Participants included Rhode Island residents aged 12 years and older who were previously diagnosed with COVID-19 and unvaccinated at the time of first infection, stratified into 3 subpopulations: long-term congregate care (LTCC) residents, LTCC employees, and the general population (ie, individuals not associated with congregate settings). Data were analyzed from October 2021 to January 2022. Completion of the primary vaccination series, defined as 14 days after the second dose of an mRNA vaccine or 1 dose of vector virus vaccine. The main outcome was SARS-CoV-2 reinfection, defined as a laboratory-confirmed positive result on a polymerase chain reaction (PCR) or antigen test at least 90 days after the first laboratory-confirmed positive result on a PCR or antigen test. Overall, 3124 LTCC residents (median [IQR] age, 81 [71-89]; 1675 [53.6%] females), 2877 LTCC employees (median [IQR] age, 41 [30-53]; 2186 [76.0%] females), and 94 516 members of the general population (median [IQR] age, 35 [24-52] years; 45 030 [47.6%] females) met eligibility criteria. Probability of reinfection at 9 months for those who remained unvaccinated after recovery from prior COVID-19 was 13.0% (95% CI, 12.0%-14.0%) among LTCC residents, 10.0% (95% CI, 8.8%-11.5%) among LTCC employees, and 1.9% (95% CI, 1.8%-2.0%) among the general population. Completion of the primary vaccination series after infection was associated with 49% (95% CI, 27%-65%) protection among LTCC residents, 47% (95% CI, 19%-65%) protection among LTCC employees, and 62% (95% CI, 56%-68%) protection in the general population against reinfection, adjusting for potential sociodemographic and clinical confounders and temporal variation in infection rates. These findings suggest that risk of SARS-CoV-2 reinfection after recovery from COVID-19 was relatively high among individuals who remained unvaccinated. Vaccination after recovery from COVID-19 was associated with reducing risk of reinfection by approximately half.

Serum Neutralizing Antibody Titers 12 Months After Coronavirus Disease 2019 Messenger RNA Vaccination: Correlation to Clinical Variables in an Adult, US Population.

BackgroundWe studied whether comorbid conditions affect strength and duration of immune responses after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA vaccination in a US-based, adult population.MethodsSera (before and after BNT162b2 vaccination) were tested serially up to 12 months after 2 doses of vaccine for SARS-CoV-2-anti-Spike neutralizing capacity by pseudotyping assay in 124 individuals; neutralizing titers were correlated to clinical variables with multivariate regression. Postbooster (third dose) effect was measured at 1 and 3 months in 72 and 88 subjects, respectively.ResultsAfter completion of primary vaccine series, neutralizing antibody half maximal inhibitory concentration (IC50) values were high at 1 month (14-fold increase from prevaccination), declined at 6 months (3.3-fold increase), and increased at 1 month postbooster (41.5-fold increase). Three months postbooster, IC50 decreased in coronavirus disease (COVID)-naïve individuals (18-fold increase) and increased in prior COVID 2019 (COVID-19+) individuals (132-fold increase). Age >65 years (β = −0.94, P = .001) and malignancy (β = −0.88, P = .002) reduced strength of response at 1 month. Both neutralization strength and durability at 6 months, respectively, were negatively affected by end-stage renal disease ([β = −1.10, P = .004]; [β = −0.66, P = .014]), diabetes mellitus ([β = −0.57, P = .032]; [β = −0.44, P = .028]), and systemic steroid use ([β = −0.066, P = .032]; [β = −0.55, P = .037]). Postbooster IC50 was robust against WA-1 and B.1.617.2. Postbooster neutralization increased with prior COVID-19 (β = 2.9, P < .0001), and malignancy reduced neutralization response (β = −0.68, P = .03), regardless of infection status.ConclusionsMultiple clinical factors affect the strength and duration of neutralization response after primary series vaccination, but not the postbooster dose strength. Malignancy was associated with lower booster-dose response regardless of prior COVID infection, suggesting a need for clinically guided vaccine regimens.

Determining the Prevalence and Correlates of COVID-19 Booster Vaccine Hesitancy in the Singapore Population Following the Completion of the Primary Vaccination Series

In response to declining vaccine-induced immunity and the emergence of new COVID-19 variants, COVID-19 booster vaccination programmes have been widely launched in several high-income countries. However, public response has been slow, and scepticism about these programmes is rising in these settings. This study sought to identify the sociodemographic, emotional, and psychological factors associated with COVID-19 booster vaccine hesitancy in Singapore. Derived from a community cohort, 1005 fully vaccinated adults (62.1% female, mean age = 42.6 years) that had not received their COVID-19 booster shots completed an online survey between October and November 2021 on vaccination beliefs, intentions, and behaviours. Results indicated that despite completing the primary COVID-19 vaccination, 30.5% of those surveyed were hesitant about receiving the booster shot (25.9% unsure; 4.7% refused the booster), and 39.2% perceived more vaccine risks than benefits. Multivariable models indicated that a tertiary education, lower COVID-19 threat perception, lower perceived benefits, higher perceived concerns, a decreased need for booster vaccination, and a lower benefit/concerns differential score were associated with higher odds of booster vaccine hesitancy. Success in the primary vaccination series may not warrant widespread public acceptance for recurrent COVID-19 vaccination doses. In addressing booster vaccine hesitancy as restrictive measures and mandates are lifted, health perceptions relevant or unique to booster vaccine uptake should be considered.

Evaluating clinical effectiveness of SARS-CoV-2 vaccine in solid organ transplant recipients: A propensity score matched analysis.

BackgroundSolid organ transplant recipients (SOTRs) are at disproportionate risk for severe Coronavirus Disease 2019 (COVID‐19). Vaccination is a key preventative strategy but is associated with decreased humoral responses among SOTR. Whether dampened immune responses correlate with reduced clinical effectiveness is unclear. Our study was designed to evaluate the clinical effectiveness of SARS‐CoV‐2 vaccination in the early vaccine era.MethodsWe conducted a retrospective cohort study comparing SARS‐CoV‐2 infection rates between SOTRs who received two doses of mRNA or one dose of Ad26.Cov2.S vaccine and those not fully vaccinated (partially vaccinated and unvaccinated). To evaluate clinical effectiveness of vaccine, cause‐specific Cox regression model and modified Poisson regression model were built using the propensity score‐matched cohort. Additionally, the clinical outcomes of COVID‐19 of fully vaccinated and not fully vaccinated SOTR were compared.ResultsOf 2705 SOTRs, 1668 were included in our final matched analysis, which showed a 73% reduction of SARS‐CoV‐2 infection and 76% reduction of all‐cause‐mortality among fully vaccinated patients. Thirty‐nine SOTRs developed SARS‐CoV‐2 infection, including nine fully vaccinated and 30 not fully vaccinated. Among fully vaccinated patients, 22% had severe/critical COVID‐19 and 0% mortality versus not fully vaccinated SOTRs, of whom 37% had severe/critical COVID‐19 and 6.67% COVID‐19‐related mortality.ConclusionIn SOTRs, completion of primary vaccine series in the early vaccine era was associated with a significant reduction of COVID‐19 and was protective against severe/critical disease and death. Further studies are needed to evaluate the clinical effectiveness of current vaccine recommendations for SOTR against emerging new variants.

Clinical Nudge Impact on Herpes Zoster Vaccine Series Completion in Pharmacies

A new recombinant herpes zoster vaccine has advanced efforts to prevent shingles, but its multidose regimen introduces potential barriers to full protection that must be managed by community pharmacies. To address this potential patient management challenge, a pharmacy records clinical support tool was implemented to assist pharmacy staff in managing herpes zoster vaccine dose completion. Beginning in November 2018, a large community pharmacy chain (operating in 36 states) implemented a provider nudge within its clinical decision support tool across all locations that fit seamlessly into the existing workflow, alerting the pharmacy staff of the need for a patient's second dose. Initial and second doses were followed over 2 overlapping, 10-month periods before and after system launch. Differences in vaccine completion rates before and after the system was operational were assessed by chi-square tests and predictors of completion, controlling for store- and patient-level characteristics, and were analyzed by multivariable logistic regression and generalized linear models throughout 2021. Across 2,271 pharmacies, 71,459 and 41,982 initial doses of the herpes zoster vaccine were given in the baseline and intervention period, respectively. The proportion of patients completing both doses increased slightly after system implementation (before: 71.9%, after: 75.2%; p&lt;0.0001). However, dramatic improvements in time to dose completion were observed (before: 109.8 days, after: 93.3 days; p&lt;0.001), and changes were significant in stores in all but 4 states. Results suggest that the use of a clinical nudge improved the occurrence of and time to herpes zoster vaccine dose completion in adults across the U.S.

The feasibility and acceptability of a pilot randomized controlled trial testing pharmacy-based HPV vaccine completion.

Immunizing pharmacists can administer vaccines; however, they are less likely to administer adolescent vaccines such as vaccines that protect against human papillomavirus (HPV). Although past research has recommended incorporating pharmacists to increase adolescent vaccination, few intervention studies have tested healthcare delivery models that incorporate pharmacists to aid in vaccine series completion. This research explored the feasibility and acceptability of an intervention in which pharmacists administered booster doses of the HPV vaccine series. Between April 2019 and February 2020, the research team recruited participants for a pilot randomized controlled trial hosted in one federally qualified health center (FQHC) clinic. Researchers asked intervention group participants to complete the HPV vaccine series with their community pharmacists and control group participants to complete the series at their FQHC. We conducted a pre- and post-intervention surveys and in-depth interviews with both intervention and control group participants. A total of 33 parents of children who received the first dose of the HPV vaccine enrolled in the study of whom 8 intervention and 11 control group participants completed post-intervention data collection. Although there were no statistically significant changes in vaccine completion and in psychometric variables, we did find that pharmacist-delivered HPV vaccination was acceptable, due, primarily, to convenience. Barriers to receiving pharmacist-administered vaccines included pharmacies' lack of stocking the vaccine and insurance-related barriers to care. Although a promising and acceptable healthcare delivery approach, there are still barriers for caregivers to have their children vaccinated against HPV at their community pharmacies.

Increases in human papillomavirus vaccine coverage over 12 months among a community-recruited cohort of gay, bisexual, and other men who have sex with men in Canada

BackgroundStarting in 2015/16, most Canadian provinces introduced publicly-funded human papillomavirus (HPV) vaccination programs for gay, bisexual, and other men who have sex with men (GBM) aged ≤ 26 years. We estimated 12-month changes in HPV vaccine coverage among community-recruited GBM from 2017 to 2021 and identified baseline factors associated with vaccine initiation (≥1 dose) or series completion (3 doses) among participants who were unvaccinated or partially vaccinated at baseline. MethodsWe recruited sexually-active GBM aged ≥ 16 years in Montreal, Toronto, and Vancouver, Canada, from 02/2017 to 08/2019 and followed them over a median of 12 months (interquartile range = 12–13 months). We calculated the proportion who initiated vaccination (≥1 dose) or completed the series (3 doses) by 12-month follow-up. Analyses were stratified by city and age-eligibility for the publicly-funded programs at baseline (≤26 years or > 26 years). We used multivariable logistic regression to identify baseline factors associated with self-reported incident vaccine initiation or series completion. ResultsAmong 165 unvaccinated participants aged ≤ 26 years at baseline, incident vaccine initiation (≥1 dose) during follow-up was 24.1% in Montreal, 33.3% in Toronto, and 38.9% in Vancouver. Among 1,059 unvaccinated participants aged > 26 years, incident vaccine initiation was 3.4%, 8.9%, and 10.9%, respectively. Higher education and trying to access pre-exposure prophylaxis for HIV were associated with incident vaccination among those aged ≤ 26 years, while younger age, residing in Vancouver (vs. Montreal), being diagnosed with anogenital warts, having both government and private extended medical insurance, and being vaccinated against influenza were associated with incident vaccination among those aged > 26 years. ConclusionsWe observed substantial gains in HPV vaccine coverage among young GBM within 5 + years of targeted program implementation, but gaps remain, particularly among older men who are ineligible for publicly-funded programs. Findings suggest the need for expanded public funding or insurance coverage for HPV vaccines.

SARS-CoV-2 vaccine effectiveness against infection, symptomatic and severe COVID-19: a systematic review and meta-analysis

BackgroundThe temporal evolution of SARS-CoV-2 vaccine efficacy and effectiveness (VE) against infection, symptomatic, and severe COVID-19 is incompletely defined. The temporal evolution of VE could be dependent on age, vaccine types, variants of the virus, and geographic region. We aimed to conduct a systematic review and meta-analysis of the duration of VE against SARS-CoV-2 infection, symptomatic COVID-19 and severe COVID-19.MethodsMEDLINE, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, the World Health Organization Global Literature on Coronavirus Disease, and CoronaCentral databases were searched and studies were selected. Independent reviewers selected randomized controlled trials and cohort studies with the outcome of interest. Independent reviewers extracted data, and assessed the risk of bias. Meta-analysis was performed with the DerSimonian-Laird random-effects model with Hartung-Knapp-Sidik-Jonkman variance correction. The GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach was used to assess certainty (quality) of the evidence. Primary outcomes included VE as a function of time against SARS-CoV-2 infection, symptomatic and severe COVID-19.ResultsEighteen studies were included representing nearly 7 million individuals. VE against all SARS-CoV-2 infections declined from 83% in the first month after completion of the original vaccination series to 22% at 5 months or longer. Similarly, VE against symptomatic COVID-19 declined from 94% in the first month after vaccination to 64% by the fourth month. VE against severe COVID-19 for all ages was high overall, with the level being 90% (95% CI, 87–92%) at five months or longer after being fully vaccinated. VE against severe COVID-19 was lower in individuals ≥ 65 years and those who received Ad26.COV2.S.ConclusionsVE against SARS-CoV-2 infection and symptomatic COVID-19 waned over time but protection remained high against severe COVID-19. These data can be used to inform public health decisions around the need for booster vaccination.

Governmental Incentives, Satisfaction with Health Promotional Materials, and COVID-19 Vaccination Uptake among Community-Dwelling Older Adults in Hong Kong: A Random Telephone Survey.

COVID-19 vaccination is proven to be effective and safe for older adults. This study investigated the impacts of incentives and health promotional materials provided by the government on the completion of the primary COVID-19 vaccination series among older adults in Hong Kong. Participants were Chinese-speaking community-dwelling adults aged ≥65 years. Telephone numbers were randomly selected from up-to-date Hong Kong telephone directories. A total of 440 participants completed the telephone interview. Logistic regression models were fitted. Among the participants, 58.4% had completed the primary COVID-19 vaccination series. Most participants believed that incentives provided by the government had almost no impact on increasing their motivation to receive COVID-19 vaccination, and less than half thought that vaccination promotional materials produced by the government could address their concerns and help them make decisions. After adjustment for significant background characteristics, we found perceived higher impacts of the incentives and belief that vaccination promotional materials produced by the government could address their concern and were helpful for them to make decisions to be associated with a higher rate of completion of primary COVID-19 vaccination series. Perceptions supporting COVID-19 vaccination and less decisional conflict regarding the choice of vaccine were also positively associated with the dependent variable. Government should develop incentives and health promotional materials tailored to the needs of older adults.

Evaluating vaccination coverage and timeliness in American Indian/Alaska Native and non-Hispanic White children using state immunization information system data, 2015-2017

Comprehensive estimates of vaccination coverage and timeliness of vaccine receipt among American Indian/Alaska Native (AI/AN) children in the United States are lacking. This study’s objectives were to quantify vaccination coverage and timeliness, as well as the proportion of children with specific undervaccination patterns, among AI/AN and non-Hispanic White (NHW) children ages 0–24 months in Montana, a large and primarily rural U.S. state. Data from Montana’s immunization information system (IIS) for children born 2015–2017 were used to calculate days undervaccinated for all doses of seven recommended vaccine series. After stratifying by race/ethnicity, up-to-date coverage at key milestone ages and the proportion of children demonstrating specific patterns of undervaccination were reported. Among n = 3,630 AI/AN children, only 23.1% received all recommended vaccine doses on-time (i.e., zero days undervaccinated), compared to 40.4% of n = 18,022 NHW children (chi-square p < 0.001). A greater proportion of AI/AN children were delayed at each milestone age, resulting in lower overall combined 7-vaccine series completion, by age 24 months (AI/AN: 56.6%, NHW: 64.3%, chi-square p < 0.001). As compared with NHW children, a higher proportion of AI/AN children had undervaccination patterns suggestive of structural barriers to accessing immunization services and delayed starts to vaccination. More than three out of four AI/AN children experienced delays in vaccination or were missing doses needed to complete recommended vaccine series. Interventions to ensure on-time initiation of vaccine series at age 2 months, as well initiatives to encourage completion of multi-dose vaccine series, are needed to reduce immunization disparities and increase vaccination coverage among AI/AN children in Montana.

MO828: The Humoral Response of SARS-COV-2 Vaccine in Haemodialysis

BACKGROUND AND AIMSAlthough vaccination against COVID-19 infection in dialysis patients is an urgent issue of worldwide concern, literature data regarding the antibody level and their kinetics over time and the efficacy towards complete COVID-19 vaccination and booster dose in these patients is inconclusive.METHODWe retrospectively assessed the response to COVID-19 vaccination, after the completion of vaccine series and after a booster dose in haemodialysis (HD) patients. IgG antibodies to the spike protein S1 subunit of SARS-CoV-2 were measured using ELISA at least 15 days after completion of a vaccination series, 1 month and finally 15–30 days after the booster dose.RESULTSAmong the 28 vaccinated HD patients (mean age = 59.8 years, 100% male) with two doses of mRNA vaccine, a seroconversion was documented in all the patients (100%) with a median antibody titre of 3270.6 U/mL (IQR: 94–40.000). We recorded 9 out of 28 early responders (peak level at 2 weeks) and 19/28 late responders (peak level at 1 month). The early responders were younger (56.25 years versus 61.63; P = 0.07), without cardiovascular history (88% versus 44%; P = 0.042) or diabetes (100% versus 63%; P = 0.042), compared with late responders. On multivariate analysis, combined haemoperfusion and haemodialysis (HR = 0.167, 95% confidence interval: 0.034–0.826; P = 0.028) was an independent prognostic factor for early responders. After 6 months, all the patients received a booster mRNA dose. The patients presented median antibody levels of 33.939 U/mL (IQR: 1112–181.223), much higher titre than the first peak. Finally, four patients, all from the late responders group, presented COVID-19 infection during the vaccination period (two patients in the early period <1 month and two patients in the late period >5 months).CONCLUSIONHD patients develop a substantial humoral response against SARS-CoV2 and the booster dose much higher response. The early responders presented more rapidly and more efficacious antibody levels, while the combined haemoperfusion and haemodialysis emerged as a positive predictor factor.

MO224: Antibody Responses to a 3RD Booster Dose of SARS-COV-2 Vaccines in Patients with Vasculitides and Renal Involvement

BACKGROUND AND AIMSImmunosuppressed patients are in general less likely to achieve a detectable antibody response to SARS-CoV-2 after the primary doses of vaccine administration. However, there are limited data for the effect of a third booster dose in this patient population, especially for those with vasculitides and renal involvement treated with rituximab (RTX).METHODWe retrospectively assessed the antibody responses to SARS-CoV-2 vaccination, after completion of the primary vaccine series (two doses) and after the booster third dose, in patients with vasculitides and renal involvement. IgG antibodies to the spike protein S1 subunit of SARS-CoV-2 were measured using ELISA >1 month after completion of the primary vaccination series (two doses of Pfizer or AstraZeneca vaccines) and 15–30 days after the third booster dose (Pfizer, given 3–6 months after the second dose).RESULTSWe included 20 patients with vasculitis [AAV, n = 16 (80%), IgAV, n = 4 (20%)] and renal involvement. All patients received immunosuppressives, including RTX (80%), MMF/AZA (15%), cyclophosphamide (5%), while half of patients were on glucocorticoids. The seroconversion rate after the primary two doses (Pfizer n = 8/16, Astra-Zeneca n = 1/1) was 53%, which increased to 67% after the third booster dose (Pfizer, n = 12/18). Similarly, the median antibody titers increased from 451 U/mL [interquartile range (IQR) 81–10.845] after the second dose to 1016 U/mL (ΙQR: 64–37.568) after the booster dose. Regarding patients treated with RTX, the respective response rates after the second and third dose were 58% and 62%. Seropositive patients after the third dose tended to have lower previous cumulative exposure to RTX compared with seronegative ones (4.55 versus 5.5 g, P = .62, respectively). No vaccine side effects or disease relapses were noted after the three vaccine doses.CONCLUSIONIn our patient cohort with systemic vasculitis and renal involvement treated mainly with RTX, a third booster vaccine dose increased the seropositivity rate from 53% to 67%. Nevertheless, one-third of patients did not achieve seroconversion. Whether a fourth booster dose could benefit these patients is still unknown.

Determining the Impact of a Community-Based Intervention on Knowledge Gained and Attitudes Towards the HPV Vaccine in Virginia

HPV vaccination series completion rates have increased steadily in the USA, yet specific areas continue to be burdened by HPV-related cancers, including rural areas of Virginia. The primary purpose of this study is to compare the impact of an community driven educational film about HPV on intention to vaccinate and knowledge gained in urban and rural areas of Virginia. From October 2016 to September 2019, the CDC-approved documentary “Someone You Love: The HPV Epidemic” was screened and followed by a Q&A session. Intention to vaccinate and knowledge gained after seeing the DVD intervention were measured through a pre-post-survey and analyzed data using chi-squared tests. The sample included males and females of all races and ages 18+ that identified as either student, parent/guardian, and/or healthcare provider from rural and urban geographical areas. Changes in knowledge about HPV were statistically significant in two out of seven questions (p < 0.05). Changes in attitude were statistically significant in every attitude-based question about HPV (p < 0.05). There were significant differences in knowledge gained and attitudes towards the HPV vaccine when comparing urban and rural locations as well. More research is needed to explore the efficacy of community-based interventions to increase uptake and series completion of HPV vaccination, particularly in rural areas most impacted by HPV-associated cancers.

Progression to Critical Illness and Death in Patients With Breakthrough Hospitalizations.

BackgroundCharacterization of disease progression and outcomes after coronavirus disease 2019 (COVID-19)–related hospitalization in vaccinated compared with unvaccinated individuals is limited.MethodsThis was a retrospective case–control study of symptomatic vaccinated (cases) and unvaccinated (controls) participants hospitalized for COVID-19 between December 30, 2020, and September 30, 2021, in Southeast Michigan. Hospitalized adult patients with lab-confirmed COVID-19 were identified through daily census report. Breakthrough infection was defined as detection of severe acute respiratory syndrome coronavirus 2 ≥14 days after completion of the primary vaccination series. The association between prior vaccination and critical COVID-19 illness (composite of intensive care unit [ICU] admission, invasive mechanical ventilation [IMV], 28-day mortality) was examined.ResultsTwo hundred ten (39%) fully vaccinated and 325 (61%) unvaccinated patients were evaluated. Compared with controls, cases were older, had more comorbidities (4 [3–7] vs 2 [1–4]; P < .001), and were more likely to be immunocompromised. Cases had less severe symptoms compared with controls (2 [1–2] vs 2 [2–3]; P < .001) and were less likely to progress to critical COVID-19 illness (33.3% vs 45.5%; P < .001); 28-day mortality was significantly lower in cases (11.0% vs 24.9%; P < .001). Symptom severity (odds ratio [OR], 2.59; 95% CI, 1.61–4.16; P < .001) and modified Sequential Organ Failure Assessment score on presentation (OR, 1.74; 95% CI, 1.48–2.06; P < .001) were independently associated with development of critical COVID-19 illness. Prior vaccination (OR, 0.528; 95% CI, 0.307–0.910; P = .020) was protective.ConclusionsCOVID-19-vaccinated patients were less likely to develop critical COVID-19 illness and more likely to survive. Disease severity at presentation was a predictor of adverse outcomes regardless of vaccination status.