Effectiveness of CoronaVac, ChAdOx1, BNT162b2 and Ad26.COV2.S among individuals with prior SARS-CoV-2 infection in Brazil

Background. COVID-19 vaccines have proven highly effective among SARS-CoV-2 naive individuals, but their effectiveness in preventing symptomatic infection and severe outcomes among individuals with prior infection is less clear. Methods. Utilizing national COVID-19 notification, hospitalization, and vaccination datasets from Brazil, we performed a case-control study using a test-negative design to assess the effectiveness of four vaccines (CoronaVac, ChAdOx1, Ad26.COV2.S and BNT162b2) among individuals with laboratory-confirmed prior SARS-CoV-2 infection. We matched RT-PCR positive, symptomatic COVID-19 cases with RT-PCR-negative controls presenting with symptomatic illnesses, restricting both groups to tests performed at least 90 days after an initial infection. We used multivariable conditional logistic regression to compare the odds of test positivity, and the odds of hospitalization or death due to COVID-19, according to vaccination status and time since first or second dose of vaccines. Findings. Among individuals with prior SARS-CoV-2 infection, vaccine effectiveness against symptomatic infection ≥ 14 days from vaccine series completion was 39.4% (95% CI 36.1-42.6) for CoronaVac, 56.0% (95% CI 51.4-60.2) for ChAdOx1, 44.0% (95% CI 31.5-54.2) for Ad26.COV2.S, and 64.8% (95% CI 54.9-72.4) for BNT162b2. For the two-dose vaccine series (CoronaVac, ChAdOx1, and BNT162b2), effectiveness against symptomatic infection was significantly greater after the second dose compared with the first dose. Effectiveness against hospitalization or death ≥ 14 days from vaccine series completion was 81.3% (95% CI 75.3-85.8) for CoronaVac, 89.9% (95% CI 83.5-93.8) for ChAdOx1, 57.7% (95% CI -2.6-82.5) for Ad26.COV2.S, and 89.7% (95% CI 54.3-97.7) for BNT162b2.

Personalized Reminders for Immunization Using Short Messaging Systems to Improve Human Papillomavirus Vaccination Series Completion: Parallel-Group Randomized Trial

Background Completion rates among adolescents who initiate the human papillomavirus (HPV) vaccine 3-dose series are low. SMS text message vaccine reminders are effective, but less is known about the best types for HPV series completion or the ability to assess and target vaccine decision-making stage. Objective The aim of this study is to compare the effectiveness of HPV vaccine series completion in minority adolescents who received precision and educational versus conventional SMS text message reminders. Methods Enrolled parents of adolescents aged 9-17 years who received the first HPV vaccine dose at 1 of the 4 academic-affiliated community health clinics in New York City were randomized 1:1 to 1 of the 2 parallel, unblinded arms: precision SMS text messages (which included stage-targeted educational information, next dose due date, and site-specific walk-in hours) or conventional SMS text messages without educational information. Randomization was stratified according to gender, age, and language. The primary outcome was series completion within 12 months. In post hoc analysis, enrollees were compared with concurrent nonenrollees and historical controls. Results Overall, 956 parents were enrolled in the study. The precision (475 families) and conventional (481 families) SMS text message arms had similarly high series completion rates (344/475, 72.4% vs 364/481, 75.7%). A total of 42 days after the first dose, two-thirds of families, not initially in the preparation stage, moved to preparation or vaccinated stage. Those in either SMS text message arm had significantly higher completion rates than nonenrollees (708/1503, 47.1% vs 679/1503, 45.17%; P<.001). Even after removing those needing only 2 HPV doses, adolescents receiving any SMS text messages had higher completion rates than historical controls (337/2823, 11.93% vs 981/2823, 34.75%; P<.001). A population-wide effect was seen from 2014 to 2016, above historical trends. Conclusions SMS text message reminders led to timely HPV vaccine series completion in a low-income, urban, minority study population and also led to population-wide effects. Educational information did not provide an added benefit to this population. Trial Registration ClinicalTrials.gov NCT02236273; https://clinicaltrials.gov/ct2/show/NCT02236273

Effect of a Community-Based Hepatitis B Virus Infection Detection Combined with Vaccination Program in China

Evidence on the effectiveness of hepatitis B virus (HBV) infection screening and vaccination programs remains rare in China. We used a quasi-experimental method, propensity score matching, to evaluate the effects of a community-based HBV infection detection combined with vaccination (HBVIDV) program in a pilot. Data were retrieved from the HBVIDV program implemented between July 2019 and June 2020. Outcomes were the difference between the treatment and control groups in hepatitis B vaccination (≥1 dose), hepatitis B vaccine series completion (≥3 doses), and serologic evidence of vaccine-mediated immunity. Altogether, 26,180 individuals were included, where 6160 (23.5%) individuals were assigned to the treatment group, and 20,020 (76.5%) individuals were assigned to the control group. After propensity score matching, 5793 individuals were matched. The rates of hepatitis B vaccination, hepatitis B vaccine series completion, and prevalence of vaccine-mediated immunity in the treatment and control groups were 29.0% vs. 17.8%, 22.1% vs. 13.1%, and 38.2% vs. 27.6%, respectively. The HBVIDV program was significantly associated with increased hepatitis B vaccination rate (OR, 1.884, 95% CI 1.725–2.057), hepatitis B vaccine series completion rate (OR, 1.872, 95% CI 1.696–2.065), and prevalence of vaccine-mediated immunity (OR, 1.623, 95% CI 1.501–1.755). The greater magnitude of association between HBVIDV program and outcomes was observed among adults aged 35–54 years and adults who live in rural areas. The HBVIDV program was effective in increasing the hepatitis B vaccination rate, hepatitis B vaccine series completion rate, and prevalence of vaccine-mediated immunity among adults in the pilot. Further focusing the program on special populations and regions may produce more effective results.

Change in COVID-19 risk over time following vaccination with CoronaVac: A test-negative case-control study

Objective To estimate the change in odds of covid-19 over time following primary series completion of the inactivated whole virus vaccine, CoronaVac (Sinovac Biotech) in São Paulo State, Brazil. Design Test negative case-control study. Setting Community testing for covid-19 in São Paulo state, Brazil. Participants Adults aged 18-120 years who were residents of São Paulo state, without a previous laboratory-confirmed covid-19 infection, who received two doses of CoronaVac, and underwent reverse transcription polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 from 17 January to 30 September 2021. Main outcome measures RT-PCR-confirmed symptomatic covid-19 and associated hospital admissions and deaths. Cases were pair-matched to test-negative controls by age (in 5-year bands), municipality of residence, healthcare worker (HCW) status, and date of RT-PCR test (±3 days). Conditional logistic regression was adjusted for sex, number of covid-19-associated comorbidities, race, and previous acute respiratory infection. Results From 137,820 eligible individuals, 37,929 cases with symptomatic covid-19 and 25,756 test-negative controls with covid-19 symptoms were formed into 37,929 matched pairs. Adjusted odds ratios of symptomatic covid-19 increased with time since series completion, and this increase was greater in younger individuals, and among HCWs compared to non-HCWs. Adjusted odds ratios of covid-19 hospitalisation or death were significantly increased from 98 days since series completion, compared to individuals vaccinated 14-41 days previously: 1.40 (95% confidence interval 1.09 to 1.79) from 98-125 days, 1.55 (1.16 to 2.07) from 126-153 days, 1.56 (1.12 to 2.18) from 154-181 days, and 2.12 (1.39-3.22) from 182 days. Conclusions In the general population of São Paulo state, Brazil, an increase in odds of moderate and severe covid-19 outcomes was observed over time following primary series completion with CoronaVac.

07. Recombinant Zoster Vaccine (RZV) Second-Dose Completion in Adults Age 50‒64 Years in the United States

Background In 2018, CDC recommended a highly efficacious adjuvanted recombinant zoster vaccine (RZV, Shingrix) as a 2-dose series for prevention of herpes zoster (HZ) for immunocompetent persons age ≥50 years, with the 2nd dose recommended 2–6 months after the 1st dose. Among Medicare beneficiaries, 2-dose series completion 6 months and 12 months post initiation was 78% and 86%, respectively. Here we estimate the proportion of adults age 50–64 years who completed the 2-dose RZV series within 6 or 12 months after receiving their 1st dose, by using two administrative claims databases. Methods We used medical and pharmaceutical claims data from October 2017‒March 2020 IQVIA® PharMetrics Plus and October 2017‒October 2020 IBM® MarketScan® databases. RZV vaccination was defined using Current Procedural Terminology and National Drug Codes. We allowed for sufficient follow-up time by examining 1st doses given at least 6 or 12 months prior to the end of the study period in both databases. Place of administration was available in IQVIA data. Results Among persons age 50‒64 years, in IQVIA and MarketScan, 70% and 68% received their 2nd RZV dose within 6 months, respectively, and 79% and 81% received their 2nd dose within 12 months, respectively. The median age of 1st dose of RZV vaccination was 60 years and ~60% were female [Table 1]. When the 2nd dose was administered within 12 months, the median interval between 1st and 2nd doses was 104 and 98 days in the IQVIA and MarketScan databases, respectively. Characteristics by age, sex, or region were similar in persons who received 1 RZV dose vs. 2 RZV doses [Table 1]. Among those who received only 1 RZV dose with at least 12 months of follow-up time, 55% of vaccinations occurred at ambulatory medical provider offices and 40% at pharmacies; among 2 doses recipients, 33% of vaccinations occurred at provider offices and 62% at pharmacies. Conclusion Among 50‒64-year-olds, 2-dose RZV series completion was ~70% within 6 months and 80% within 12 months of initiation. The findings were similar across two administrative claims databases. Availability of RZV at pharmacies has potentially helped to increase RZV 2nd dose completion rates. Disclosures All Authors: No reported disclosures

146. Intact Sense of Taste and Smell During COVID-19 Infection Is Associated with Absence of of SARS-CoV-2 Spike Protein Antibody Responses within 3 Months of Symptomatic Illness

Background Although studies show most COVID-19 survivors have post-infection immunity against SARS-CoV-2 that could prevent re-infection, there is still a need to identify the breadth of antibody (Ab) responses associated with clinical phenotypes. We characterized Ab profiles at the estimated peak of Ab diversity among adults with recovered SARS-CoV-2 infections and determined their relationships with clinical factors. Methods From April-June 2020, 41 health system employees with PCR-confirmed symptomatic COVID-19 infection enrolled 8-10 weeks after symptom onset. Symptom questionnaires including baseline demographics, COVID-19 symptoms, disease severity, and disease duration were collected and plasma samples were assayed using a custom Luminex Multiplex platform (Figure 1) to measure the antibody response against 20 COVID-19 related antigens (Figure 2). Differences in Ab profile titers among different groups were tested using nonparametric t test and Benjamini-Hochberg adjustment for multiplicity. Associations were considered significant at FDR&lt; 0.05. Figure 1: Description of the Luminex Serology Assay Figure 2: List of the COVID-19 Related Antigens and Controls Measured Results Mean age was 48 years (range 27-68), with 51% female, 37% White, 32% Black, 29% Asian, and 17% LatinX. Ab profiles (Figure 3) showed 100% cross-reactivity with related alpha and beta coronavirus, and 95% with SARS-CoV-1. 78% had Abs against SARS-CoV-2 nucleocapsid protein (NCP). However, 29% of patients had no immune response against the four spike protein epitopes. These participants also reported fewer symptoms, including no cases of anosmia/ageusia, suggesting mild illness. Anosmia/ageusia, fever, and cough associated significantly with higher Ab titers (Figure 4). Conclusion Broad immune responses to various SARS-CoV-2 and related antigens were found among a heterogeneous patient population. However, less than 3 months after symptom onset, protective Ab responses to SARS-CoV-2 spike proteins were not detected in nearly one-third of recovered patients, primarily with mild infection. Intact sense of smell and taste demonstrated the greatest association with loss of seroprotective SARS-CoV-2 Ab responses, which may be clinically useful to predict post-infection immunity. Next steps include comparing the magnitude of Ab responses following full series completion with mRNA vaccination among this cohort. Disclosures Robert Bencshop, PhD, Eli Lilly (Employee) Josh Poorbaugh, PhD, Eli Lilly (Employee) Ajay Nirula, MD/PhD, Eli Lilly (Employee, Shareholder) Lin Zhang, PhD, Eli Lilly and Company (Employee, Shareholder) Stephanie Beasley, BA, Eli Lilly (Employee)

574. High Acceptance and Rapid Implementation of COVID-19 Vaccine in a Public HIV Clinic in Northern California: An Initial Analysis of Social Determinants

Background Safety net HIV providers face operational challenges during the COVID pandemic with services often transformed to telehealth. HIV infected persons are a priority population for SARS CoV-2 vaccination. Medical mistrust of COVID vaccines has been cited as a contributor to vaccine hesitancy. Data on efficient and successful vaccination efforts of HIV infected persons in safety net health systems is needed. In San Mateo County, Latino persons comprised 42% of all COVID cases, Whites 16%, and African Americans 2%. Methods SARS CoV2 vaccination with BNT162b2 (Pfizer–BioNTech), mRNA-1273 (Moderna) or Ad26.COV2.S (Janssen) vaccine were offered beginning February 2, 2021 through May 28, 2021 in a northern California public County HIV clinic. Clinic patients were contacted by bilingual English/Spanish speaking HIV clinic staff and appointments scheduled at County affiliated vaccination sites. Clinic staff followed up by phone with patients who did not initially accept vaccine. We calculate the percentage of patients who completed vaccine series and use multivariable logistic regression analysis to estimate the odds of series completion by patient race/ethnicity, gender and age. Results Virtually all, 95% (349/365) of HIV patients in our County HIV clinic were offered vaccine during a 17 week period. Among those, 86% (313/365) accepted and received at least one dose and 80% completed the series (292/365) at time of this analysis. Janssen vaccine was given to only 2% (7/313) patients. Series completion was highest among Latinos and Asians. Latinos had the highest odds of vaccine series completion (OR = 4.12; 95% CI 1.71 - 9.93). COVID-19 Vaccine Series Completion in a California Public HIV Clinic by Race/Ethnicity, Age and Sexual Orientation, n=364 Conclusion HIV patients offered SARS CoV2 vaccine by County HIV clinic staff with established patient care relationships had high vaccine acceptance (80%), comparable to 68% series completion in the county overall and 56% in the health equity quartile county census tracts. Latino HIV infected persons were most likely to complete the COVID vaccine series. Ryan White funded HIV clinics are ideal hubs to coordinate HIV patient COVID vaccination efforts. Adding COVID vaccine completion to HIV clinic performance measures would likely be beneficial. Disclosures All Authors: No reported disclosures

Vacteens.org: A Mobile Web app to Improve HPV Vaccine Uptake

U.S. HPV vaccine uptake remains below the Healthy People 2030 goal of 80% series completion. Parental concerns and misinformation about the efficacy and safety of the Human Papillomavirus (HPV) vaccine remain, and may be addressed by digital interventions tailored to their concerns. Reported here are results from a small scale randomized trial testing a mobile web app for parents and their adolescent daughters (ages 11–14 years) encouraging HPV vaccination in New Mexico, an ethnically-diverse U.S. state.Methods: A clinic-cluster randomized trial where pediatric clinics (n = 9) were recruited and randomized, and parent-adolescent pairs (n = 82) within clinics received either the Vacteens.org/Vacunadolescente.org mobile web app or Usual and Customary (UC) HPV Vaccination information. Parents completed online surveys at baseline and 3-months. Daughters' HPV vaccine data were collected from the New Mexico State Immunization Information System 1 year post baseline.Results: Three month survey results found Vacteens.org/Vacunadolescente.org parents to have higher positive HPV vaccine beliefs, informed decision making, intent to vaccinate and vaccine confidence outcomes than UC parents. HPV vaccine data found higher first dose HPV vaccination (Pearson χ2 = 6.13, p = 0.013, Vacteens.org/Vacunadolescente.org group 59.4%, UC group 40.6%), and higher HPV vaccination series completion (Pearson χ2 = 6.49, p = 0.011, Vacteens.org/Vacunadolescente.org group 68.4%, UC group 31.6%).Conclusions: The small trial results showed the Vacteens.org/Vacunadolescente.org web app prompted positive vaccine-related attitudes and beliefs, and more HPV vaccination initiation and series completion. Mobile web apps can make decision-making tools for HPV vaccination widely available on digital platforms, reducing vaccine hesitancy, and confusion and increase HPV vaccine uptake.