Prior Vaccination History Research Articles

COVID-19 infection and vaccination against COVID-19: Impact on managing demyelinating CNS disorders in Southern India- experience from a demyelinating disease registry.

Background and objectiveThe impact of COVID-19 infection and the effect of COVID-19 vaccinations on patients with demyelinating central nervous system disease in low middle income countries (LMIC's) have not been reported in detail earlier. We sought to identify risk factors associated with COVID-19 infection and the role of vaccination in order to develop management guidelines relevant to our patients. MethodsA total of 621 patients from our registry that included 297 MS and 324 non MS disorders (Aquaporin- 4 antibody positive [50], Myelin oligodendrocyte glycoprotein antibody positive [81], seronegative [162] and clinically isolated syndrome [31]) were contacted. COVID-19 infection and vaccination status were queried. Patients who self reported COVID-19 infection based on a positive RT PCR report were compared with non infected patients to identify factors associated with susceptibility for COVID-19 infection. Univariate and multivariate analysis of potential risk factors included demographic and clinical features, body mass index (BMI), presence of comorbidities, absolute lymphocyte count, treatment types and vaccination status. ResultsSixty seven patients with MS and 27 with non MS disorders developed COVID-19 infection. Among them 81 patients had mild infection and remained quarantined at home. All 13 patients who needed hospitalization recovered. Vaccination status was known in 582 patients among whom 69.8% had completed or taken one dose of vaccine at the time of inquiry. Majority of treated patients (61.3%) were on nonspecific immunosuppressants. In univariate analysis, presence of ≥1 comorbidity was significantly associated with COVID-19 infection in both MS (p value 0.01, OR-2.28, 95%CI- 1.18–4.4) and non MS patients (p- 0.001, OR-4.4, 95% CI-1.88–10.24). In the latter, BMI ≥ 30 (p-0.04, OR-3.27, 95% CI- 0.98–10.87) and EDSS score ≥ 3 (p-0.02, OR- 2.59,95% CI- 1.08–6.23) were other significant associations. History of prior COVID-19 vaccination was associated with reduced frequency of COVID-19 infection among MS (p- 0.001,OR- 0.24,95% CI- 0.13–0.43) and non MS patients (p- 0.0001,OR-0.14, 95% CI- 0.058–0.35). In multivariate analysis presence of comorbidities significantly increased and prior vaccination significantly reduced frequency of COVID-19 infection for both MS and related disorders. Concurrent disease modifying treatments showed a trend for association with infection. In the unvaccinated group, patients on disease modifying treatment were significantly at risk of infection, 81.5% unvaccinated and treated versus 18.5% who were unvaccinated and untreated (p- 0.0001, OR-10.1, 95% CI-0.56–2.11). ConclusionFrequency and severity of COVID-19 infection was low among our patient cohort. Higher rate of infection in the treated group was significantly seen among unvaccinated patients. Our preliminary results suggests that in LMIC's, where “off label therapies” with inexpensive immunosuppressives are the main disease modifying drugs, mRNA vaccinations appear safe and effective against severe COVID-19 infection.

The ‘Fauci Effect’: Reducing COVID-19 misconceptions and vaccine hesitancy using an authentic multimodal intervention

Social media environments enable users to proliferate misinformation surrounding COVID-19. Expert sources, such as Dr. Anthony Fauci have leveraged social media to present corrective multimedia messages. However, little is known about the efficacy of these messages in revising common misconceptions about COVID-19 and influencing behavior. In this study, we examined the efficacy of a multimodal intervention using authentic social media messages that directly addressed common COVID-19 misconceptions. Going further, we identified individual differences that influenced the effectiveness of the intervention, as well as whether those factors predicted individuals’ willingness to receive a COVID-19 vaccine. The results showed that the intervention was successful in increasing knowledge when compared to a baseline control. Those who were older and reported less vaccine hesitancy showed greater learning from the intervention. Factors that significantly predicted intention to vaccinate included receiving the intervention, vaccine confidence, vaccine hesitancy, prior flu vaccination history, age, and fear of COVID-19. These findings indicate that multimodal messages can be effectively leveraged in social media to both fight misinformation and increase intention to be vaccinated - however, these interventions may not be as effective for all individuals.

A single-center COVID-19 vaccine experience with CoronaVac and BNT162b2 in familial Mediterranean fever patients.

AimTo determine frequency of adverse events and attacks related to vaccination in recipients of CoronaVac and BNT162b2 in familial Mediterranean fever (FMF) patients, and to search whether history of prior COVID‐19 or a booster dose increases occurrence of adverse events/attacks.MethodsFMF patients were surveyed for administration of any COVID‐19 vaccine and vaccine‐related adverse events or FMF attacks. Demographic, clinical, vaccine‐related data, history of COVID‐19 infection before or after vaccination, adherence to FMF treatment during vaccination were collected.ResultsA total of 161 vaccinated FMF patients were included. Ninety‐three patients out of 161 had reported suffering from an adverse event/attack after a vaccine dose. There were 54.7% of BNT162b2 recipients who reported any adverse event after any vaccine dose in comparison to 29.9% of CoronaVac recipients (P < .001). There were 22.2% of BNT162b2 recipients who reported suffering from a FMF attack within 1 month after vaccination in comparison to 19.4% of CoronaVac recipients (P = .653). When patients with or without adverse event/attack were compared, no significant differences were observed in means of demographics, comorbid diseases, disease duration, total vaccine doses, or treatments adhered to for FMF. Rates of adverse events/attacks were similar between patients with and without prior COVID‐19. In booster recipients, adverse events/attacks were most frequent after the booster dose.ConclusionsA considerable number of FMF patients suffered from vaccine‐related adverse events/attacks, particularly with BNT162b2. No serious events or mortalities due to vaccination were detected. Demographics, clinical characteristics and prior history of vaccination did not significantly affect these results. We observed an increased rate of adverse events/attacks with booster dose administration.

Herpes Zoster in a 23-month-old Girl: A Case Report

&lt;p&gt;帶狀疱疹是潛伏在人體的水痘帶狀疱疹病毒再活化所造成。兒童帶狀疱疹狀並不常見，未滿兩歲更是罕見。本個案為1歲11個月大的女孩，過去未長過水痘，滿一歲時曾打過活性減毒的水痘疫苗。接種後第348天，在施打疫苗的左大腿（第三及第四腰椎的神經皮節）長出帶狀疱疹。經Acyclovir治療後，恢復迅速。依此個案的病史和臨床特徵推測，其帶狀疱疹可能是水痘疫苗所造成。若想確認帶狀疱疹在曾打過水痘疫苗的病人身上，到底是野生株或疫苗株的病毒所造成，最好的方法是做PCR檢驗。根據研究，水痘疫苗的確可能造成帶狀疱疹，但有施打疫苗者，其發生率和症狀均低於未施打疫苗者。整體而言，施打水痘疫苗，不僅能預防水痘，亦能預防帶狀疱疹，施打兩劑保護力更好。&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;p&gt;Herpes zoster, caused by reactivation of the varicella-zoster virus (VZV), is not commonly seen in children, especially in those under 2 years of age. We reported a case of a 23-month-old girl with herpes zoster. She had no personal history of chicken pox. She was immunized with the live attenuated varicella vaccine at 12 months of age. Nevertheless, she developed herpes zoster in the left thigh (L3-L4 dermatomes) around the immunization site 348 days after the varicella vaccination. Her clinical symptoms improved rapidly after acyclovir treatment. Based on the personal history and clinical presentation, it is possible that her herpes zoster was caused by the virus of varicella vaccine. The best way to identify wild-type or vaccine-strain VZV in a herpes zoster patient with a prior history of varicella vaccination is by viral genome detection using polymerase chain reaction (PCR). As previous studies indicate, vaccine-strain herpes zoster can occur after varicella vaccine. However, the incidence and symptoms of herpes zoster occur less often in vaccinated individuals than in unvaccinated ones. In general, varicella vaccine can prevent not only varicella but also herpes zoster. The preventive effect of two-dose varicella vaccination is better than that of one-dose vaccination.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Information nudges for influenza vaccination: Evidence from a large-scale cluster-randomized controlled trial in Finland.

Vaccination is the most effective means of preventing the spread of infectious diseases. Despite the proven benefits of vaccination, vaccine hesitancy keeps many people from getting vaccinated. We conducted a large-scale cluster randomized controlled trial in Finland to test the effectiveness of centralized written reminders (distributed via mail) on influenza vaccination coverage. The study included the entire older adult population (aged 65 years and above) in 2 culturally and geographically distinct regions with historically low (31.8%, n = 7,398, mean age 75.5 years) and high (57.7%, n = 40,727, mean age 74.0 years) influenza vaccination coverage. The study population was randomized into 3 treatments: (i) no reminder (only in the region with low vaccination coverage); (ii) an individual-benefits reminder, informing recipients about the individual benefits of vaccination; and (iii) an individual- and social-benefits reminder, informing recipients about the additional social benefits of vaccination in the form of herd immunity. There was no control treatment group in the region with high vaccination coverage as general reminders had been sent in previous years. The primary endpoint was a record of influenza vaccination in the Finnish National Vaccination Register during a 5-month follow-up period (from October 18, 2018 to March 18, 2019). Vaccination coverage after the intervention in the region with historically low coverage was 41.8% in the individual-benefits treatment, 38.9% in the individual- and social-benefits treatment and 34.0% in the control treatment group. Vaccination coverage after the intervention in the region with historically high coverage was 59.0% in the individual-benefits treatment and 59.2% in the individual- and social-benefits treatment. The effect of receiving any type of reminder letter in comparison to control treatment group (no reminder) was 6.4 percentage points (95% CI: 3.6 to 9.1, p < 0.001). The effect of reminders was particularly large among individuals with no prior influenza vaccination (8.8 pp, 95% CI: 6.5 to 11.1, p < 0.001). There was a substantial positive effect (5.3 pp, 95% CI: 2.8 to 7.8, p < 0.001) among the most consistently unvaccinated individuals who had not received any type of vaccine during the 9 years prior to the study. There was no difference in influenza vaccination coverage between the individual-benefit reminder and the individual- and social-benefit reminder (region with low vaccination coverage: 2.9 pp, 95% CI: -0.4 to 6.1, p = 0.087, region with high vaccination coverage: 0.2 pp, 95% CI: -1.0 to 1.3, p = 0.724). Study limitations included potential contamination between the treatments due to information spillovers and the lack of control treatment group in the region with high vaccination coverage. In this study, we found that sending reminders was an effective and scalable intervention strategy to increase vaccination coverage in an older adult population with low vaccination coverage. Communicating the social benefits of vaccinations, in addition to individual benefits, did not enhance vaccination coverage. The effectiveness of letter reminders about the benefits of vaccination to improve influenza vaccination coverage may depend on the prior vaccination history of the population. AEA RCT registry AEARCTR-0003520 and ClinicalTrials.gov NCT03748160.

Coronary thrombo-embolic events after Covid-19 vaccination- a single centre study

Thrombo-embolic complications after Corona virus disease-19 (COVID-19) vaccination have been previously reported. We aimed to study the coronary thrombo-embolic complications (CTE) after COVID-19 vaccination in a single centre during the initial 3 months of vaccination drive in India. All patients admitted to our hospital between 1st March 2021 and 31st May 2021 with Acute coronary syndrome (ACS) were included.Of the 89 patients [Age 55 (47–64)y, 13f] with ACS and angiographic evidence of coronary thrombus, 37 (42%) had prior vaccination history. The timing from last vaccination dose to index event was <1, 1–2, 2–4 and >4 weeks in 9(24%), 4(11%), 15(41%) and 9 (24%) respectively. ChAdOx1 nCoV-19/AZD1222 (Covishield) was the most used vaccine- 28 (76%), while 9 (24%) had BBV152 (Covaxin). Baseline characteristics were similar in both vaccinated (VG) and non-vaccinated group (NVG), except for symptom to door time [8.5 (5.75–14) vs 14.5 (7.25–24) hrs, p = 0.003]. Thrombocytopenia was not noted in any of the VG patients, while 2 (3.8%) of NVG patient had thrombocytopenia (p = 0.51). The pre- Percutaneous Coronary Intervention (PCI) Thrombolysis in Myocardial Infarction (TIMI) flow was significantly lower [1 (0–3) vs2 (1–3), p = 0.03) and thrombus grade were significantly higher [4 (2.5–5) vs 2 (1–3), p = 0.0005] in VG. The in-hospital (2.7% vs 1.9%, p = 1.0) and 30-day mortality were also similar (5.4% vs 5.8%, p = 1.0).This is the first report of CTE after COVID-19 vaccination during the first 3 months of vaccination drive in India. We need further reports to identify the incidence of this rare but serious adverse events following COVID-19 vaccination.

Response to hepatitis B vaccination in adult patients with cirrhosis of liver- A real world scenario

Background and Aim: We aimed to determine response rates to hepatitis B vaccination and its determinants in adult patients with cirrhosis of liver. Methods: This prospective study was done over a period of three years from 2019-2021. All adult patients (>18 years) with cirrhosis of liver were screened for HBsAg, anti HBc and anti HBs. Those who were negative for all were advised vaccination. For vaccine naïve patients, dose of 20 mcg intramuscular in deltoid region was administered at 0, 1 and 6 months. For those with prior history of vaccination but negative anti HBs titres, dose of 40 mcg was used at 0, 1 and 6 months. We excluded patients who were known HBs Ag positive, on oral antiviral drugs and who did not complete the recommended vaccination. Anti HBs titres were measured 2 months after completion of vaccination. Patients with anti HBs titres >10 were considered responders and those with titres <10 were labelled as non-responders. Baseline demographic parameters, anthropometry, Model of End stage liver disease (MELD) score and history of prior vaccination were compared between the two groups. Results: A total of 678 patients with cirrhosis were seen over the study period. Seventy-two were newly found to be HBs Ag +/ anti HBc + and 165 were detected to be anti HBs +. A total of 277 cases did not complete vaccination or were lost to follow up. The study cohort included 164 patients- median age 43 (18-68) years and 67% males. On follow up at 2 months after last dose of vaccination, 103 (62.8%) had anti HBs titre >10 IU/L. Non responders were significantly older than responders (48 vs 41 years, p 0.01). Conclusions: The response rate to hepatitis B vaccination in cirrhotics is 62.8%. Older patients are more likely to be non-responders.

Chest Radiograph and CT Findings in Patients Hospitalized with Breakthrough COVID-19.

PurposeTo characterize chest radiograph and CT imaging appearance in patients with breakthrough COVID-19 (defined as an illness occurring in patients that previously received a COVID-19 vaccination) in a hospital setting.Materials and MethodsIn this retrospective study, all patients admitted to the hospital between August 26 and September 8, 2021 with a positive SARS-CoV-2 reverse transcription polymerase chain reaction-confirmed infection who were fully vaccinated against COVID-19 were evaluated. Clinical, laboratory data, and outcomes were collected and assessed. All patients had chest imaging performed (either radiography, CT, or a combination of both). Chest radiographs and CTs were assessed and scored on admission and on follow up to determine the extent and type of pulmonary involvement. Descriptive statistics were used.ResultsCharts of 60 hospitalized patients that tested positive for SARS-CoV-2 were reviewed for a prior history of COVID-19 vaccination. Eight (13.3%) such patients were identified and included for analysis (mean age, 54 years; range 34–81 years; four women). Patients received either two doses of Pfizer-BioNTech (n = 6), two doses of Moderna (n = 1), or one dose of Johnson and Johnson (n = 1). Five (63%) patients were immunosuppressed at the time of presentation, and six (75%) reported respiratory symptoms. Most of the patients had normal radiographs (4 of 7; 57%). The most common chest CT findings were ground glass opacities (three of five), with mild to moderate severity scores (average, 51; range 8–88). Two patients required intensive care unit admission. However, no patients died and all were either discharged or were on room air without residual respiratory symptoms by the end of the study period.ConclusionIn hospitalized patients with COVID-19 breakthrough illness, normal to mild or moderately positive imaging findings were observed.©RSNA, 2021

A trial to evaluate the safety and immunogenicity of a 20-valent pneumococcal conjugate vaccine in populations of adults ≥65 years of age with different prior pneumococcal vaccination

IntroductionA 20-valent pneumococcal conjugate vaccine, PCV20, was developed to expand protection against vaccine-preventable pneumococcal disease. PCV20 contains the components of the 13-valent pneumococcal conjugate vaccine, PCV13, and includes capsular polysaccharide conjugates for 7 additional serotypes. Thus, PCV20 may cover those additional serotypes in individuals previously vaccinated with PCV13 or provide benefits of immunization with a conjugate vaccine to individuals previously immunized with a pneumococcal polysaccharide vaccine. This study described the safety and immunogenicity of PCV20 in adults ≥65 years of age with prior pneumococcal vaccination. MethodsThis phase 3, multicenter, randomized, open-label study was conducted in the United States and Sweden. Adults ≥65 years of age were enrolled into 1 of 3 cohorts based on their prior pneumococcal vaccination history (23-valent pneumococcal polysaccharide vaccine [PPSV23], PCV13, or both PCV13 and PPSV23). Participants were randomized 2:1 within their cohort to receive a single dose of PCV20 or PCV13 in those with prior PPSV23 only, and PCV20 or PPSV23 in those with prior PCV13 only; all participants with prior PCV13 and PPSV23 received PCV20. Safety was assessed by prompted local reactions within 10 days, systemic events within 7 days, adverse events (AEs) within 1 month, and serious AEs (SAEs) and newly diagnosed chronic medical conditions (NDCMCs) within 6 months after vaccination. Immune responses 1 month after PCV20 were assessed. ResultsThe percentages of participants reporting local reactions, systemic events, and AEs after PCV20 administration were similar across cohorts and comparable with the PCV13 and PPSV23 control groups. SAE and NDCMC rates were low in all groups. Robust immune responses, including opsonophagocytic antibody responses, to the 20 vaccine serotypes were observed 1 month after PCV20 regardless of prior pneumococcal vaccination. ConclusionsPCV20 was well tolerated and immunogenic in adults ≥65 years of age previously vaccinated with different pneumococcal vaccine regimens.Clinicaltrials.gov NCT03835975.

EFFECTIVENESS OF BCG VACCINATION AGAINST SARS-COV-2

Background: Bacillus Calmette-Guerin (BCG) vaccine is weakened Mycobacterium bovis based preparation that provides protective effects and immunotherapy against many ailments and may be tested against SARS-COV-2. Herein, we compare the prevalence of COVID-19 in countries with and without mandatory BCG vaccination program along with a study to examine its incidence in doctors working at quarantine facility with and without history of prior BCG vaccination. Methods: For cross-sectional examination, the data was collated from worldometer.info, BCG World Atlas and COVID-19 stats at National Command and Operation Centre (NCOC), Government of Pakistan accessed on Apr 30, 2021. For a real-time analysis, total of one hundred random male and female doctors working at a COVID-19 healthcare facility in Pakistan were voluntarily selected. Chi-square test was used to perform the statistical analysis with the help of SPSS-22. Results: The prevalence of COVID-19 in countries with and without a mandatory BCG vaccination policy was found to be 5,512 and 75,592 cases per million, respectively, and mortality rates were 98 and 1,435 per million, respectively. Amongst our randomly selected doctors, only 28% of the BCG vaccinated doctors were affected by COVID-19 contrary to 94% of those who were unvaccinated. Conclusions: The incidence of COVID-19 was considerably lower in the doctors with a history of BCG vaccination supported by the evidence that the countries with a universal BCG vaccine policy had a significantly low incidence and lower mortality rate due to COVID-19.

Sensitivity of Self-Reported Human Papillomavirus Vaccination History Among 18- to 26-Year-Old Men Who Have Sex With Men: Seattle, WA, 2016 to 2018.

We assessed the sensitivity of self-reported human papillomavirus (HPV) vaccination among young adult men who have sex with men (MSM) with documented HPV vaccination. During 2016-2018, MSM and transgender women aged 18 to 26 years were enrolled in Seattle, WA. A history of HPV vaccination was assessed via self-administered survey, clinic electronic medical records, and the Washington State Immunization Information System. We assessed self-report sensitivity among participants with documented prior HPV vaccination (≥1 dose) in either the electronic medical record or the Washington State Immunization Information System, and used logistic regression to compare sensitivity by age, number of doses, and time since first dose. Of 292 participants with ≥1 documented HPV vaccine dose, 243 self-reported ≥1 dose (sensitivity, 83.2%; 95% confidence interval [CI], 78.4%-87.3%). Compared with participants whose first dose was <1 year ago, the likelihood of self-report was lower among those with ≥3 years since first dose (adjusted odds ratio [aOR], 0.2; 95% CI, 0.1-0.5). Furthermore, compared with participants with only 1 documented HPV vaccine dose, the likelihood of self-reporting ≥1 dose was higher among those with 2 (aOR, 2.4; 95% CI, 1.0-5.5) or ≥3 doses (aOR, 6.2; 95% CI, 2.7-14.4). Among 115 participants with ≥3 documented doses, sensitivity for recalling ≥3 doses was 69.6% (95% CI, 60.3%-77.8%). Most young adult MSM with a documented history of HPV vaccination self-reported prior HPV vaccination. Although recall was highest in those with ≥3 doses, 30% of this fully vaccinated subgroup did not correctly recall the number of doses received, highlighting limitations of self-reporting. Furthermore, results indicating reduced recall with ≥3 years since first dose suggest that sensitivity of self-report among young adult MSM may decline over time as adolescent vaccination coverage increases.

The Spectrum of Clinical Characteristics and Complications of Tetanus: A Retrospective Cross-Sectional Study From a Developing Nation.

IntroductionWhile tetanus has largely been eradicated with the advent of the tetanus vaccine, its prevalence in Pakistan remains alarmingly high due to insufficient uptake of the vaccination program. The clinical presentations that the disease elicits range from mere opisthotonos to more sinister complications, including respiratory failure and death, often posing an insurmountable challenge for hospitals.MethodsA retrospective cross-sectional study was conducted and analyzed the medical charts of 43 patients with a confirmed diagnosis of tetanus infection. The charts were perused for the patients’ demographics, clinical characteristics, and disease outcomes. The prevalence of various clinical symptoms and complications were reported in terms of frequencies and percentages.ResultsThe mean age of the patients hovered at 29.53 ± 16.53 years, with a range of 12 to 65 years. Of those affected, 83.7% were males while 16.3% were females. Notably, none of the infected patients had a prior history of vaccination against tetanus. Trismus was noted to be the most prevalent clinical manifestation and was found in 90.70% of the patients while paraesthesia at the site of infection, found in 6.98%, was the least prevalent. The overall mortality was noted to hover at 46.5%.ConclusionWhile tetanus has largely been eradicated, its prevalence in Pakistan remains alarmingly high. The complications noted in the study have implications for the country’s public health system and aims to better inform the current state of the national vaccination program.

Impact of prior vaccination on antibody response and influenza-like illness among Australian healthcare workers after influenza vaccination in 2016

BackgroundEpidemiological studies suggest that influenza vaccine effectiveness decreases with repeated administration. We examined antibody responses to influenza vaccination among healthcare workers (HCWs) by prior vaccination history and determined the incidence of influenza infection. MethodsHCWs were vaccinated with the 2016 Southern Hemisphere quadrivalent influenza vaccine. Serum samples were collected pre-vaccination, 21–28 days and 7 months post-vaccination. Influenza antibody titres were measured at each time-point using the haemagglutination inhibition (HI) assay. Immunogenicity was compared by prior vaccination history. ResultsA total of 157 HCWs completed the study. The majority were frequently vaccinated, with only 5 reporting no prior vaccinations since 2011. Rises in titres for all vaccine strains among vaccine-naïve HCWs were significantly greater than rises observed for HCWs who received between 1 and 5 prior vaccinations (p < 0.001, respectively). Post-vaccination GMTs against influenza A but not B strains decreased as the number of prior vaccinations increased from 1 to 5. There was a significant decline in GMTs post-season for both B lineages. Sixty five (41%) HCWs reported at least one influenza-like illness episode, with 6 (4%) identified as influenza positive. ConclusionsVarying serological responses to influenza vaccination were observed among HCWs by prior vaccination history, with vaccine-naïve HCWs demonstrating greater post-vaccination responses against A(H3N2).

COVID-19 Vaccine Hesitancy and Its Determinants Among Adults with a History of Tobacco or Marijuana Use.

Decreasing COVID-19 vaccine hesitancy is an urgent challenge in the US. This study aimed to examine COVID-19 vaccine hesitancy among U.S. adults with a history of using tobacco products or marijuana. Data were collected online in 2020–2021 including respondents’ willingness to accept a COVID-19 vaccine, factors that may promote vaccine acceptance, and prior history of influenza vaccination. Logistic regression models were conducted to estimate the associations between vaccine hesitancy and demographic characteristics, substance use, the impact of the COVID-19 pandemic, and prior influenza vaccination. Among 387 respondents, 49.1% were willing to receive a COVID-19 vaccine, 26.0% were unwilling, and 24.9% were “not sure.” Blacks, suburban or rural residents, those who lived by themselves or with a family with five members or above, those who were not stressed because of the COVID-19 pandemic were more likely to say “no” to a COVID-19 vaccine. Respondents who never, only once, or during some years received an influenza vaccine were 7.0, 6.2, and 5.2 times more likely to say “no” to a COVID-19 vaccine than respondents who received an influenza vaccination every year or almost every year. The use of cigarettes, e-cigarettes, and marijuana, as well as heavy drinking of alcohol, were not associated with COVID-19 hesitancy. The associations between demographic factors and vaccine hesitancy were roughly similar for COVID-19 and influenza vaccines. Although various demographic groups have different levels of vaccine hesitancy and also have different factors to increase their acceptance, addressing misinformation related to COVID-19 vaccines, particularly concern about the safety of the vaccines is crucial in general.

Severity of COVID-19 in bacillus Calmette-Guérin vaccinated population.

PurposeConsidering the cross-protection reported for bacillus Calmette-Guérin (BCG) vaccination on viral respiratory infections, it has been proposed that it could reduce the severity of coronavirus disease 2019 (COVID-19). The objective of the current study is to investigate the association between the severity of COVID-19 with prior BCG vaccination in adult patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.Materials and MethodsAdult patients (18 years or above) with positive SARS-CoV-2 polymerase chain reaction admitted in July 2020 were included in this cross-sectional study. Patients were classified into non-severe, severe, and critical diseases. History of prior BCG vaccination and the presence of a BCG vaccination scar were recorded.ResultsOut of 103 patients, 64 patients with prior history of BCG vaccinations were compared with 39 patients without BCG vaccination in childhood. The median age was 55 years and 64 years in BCG vaccinated & non-BCG vaccinated patients (p-value=0.002). There was male predominance in both groups and frequent comorbid illnesses were hypertension and diabetes mellitus. Severe COVID-19 was found in 91 patients (88.3%) followed by non-severe disease and critical diseases i.e., 7 (6.8%) and 5 (4.9%) patients, respectively. No association of prior BCG vaccination with disease severity of COVID-19 was found in this study and mortality was 8.7%. Out of nine patients who expired only 2 (22.2%) had a prior history of BCG vaccination (p-value=0.01). Secondary infections were present in 26 patients and the majority had pneumonia.ConclusionThe BCG vaccine has no impact on the severity of COVID-19 but could have a protective role with a low mortality rate in already infected patients.

Information Nudges for Influenza Vaccination: Evidence From a Large-Scale Cluster-Randomized Controlled Trial

Background: Vaccination is the most effective means to prevent the spread of infectious diseases. Despite the proven benefits of vaccination, complacency, constraints, and lacking confidence keep many people away from getting vaccinated. This study investigates how written reminders with varying information contents to address vaccine hesitancy affect influenza vaccination coverage in two large and representative samples of older adults. Methods: We implemented a large-scale cluster-randomized controlled trial in Finland. The study included the entire elderly population (≥ 65 years of age) in two culturally and geographically distinct regions with a historically low (31·8%, N = 7398) and high (57·7%, N = 40727) influenza vaccination coverage. Participants were randomized before the influenza season 2018 – 2019 into three treatments: (i) no information letter, (ii) a standard information letter, reminding recipients about the individual benefits of vaccination, and (iii) a tailored information letter, reminding recipients about the additional social benefits of vaccination due to herd effect. The impact of varying information treatments on influenza vaccination coverage was measured using individual-level administrative health records. Findings: Our results showed that a low-cost and scalable information intervention relying on individually mailed letters increased influenza vaccination coverage by 6·4 percentage points (95% CI: 4·1 to 8·8). The effect was particularly large among individuals with no prior influenza vaccination (8·8 pp, 95% CI: 6·5 to 11·1). Moreover, we observed a substantial positive effect (5·3 pp, 95% CI: 2·8 to 7·8) among the most consistently non-vaccinated individuals who had not received any type of vaccine during the previous nine years. There were no cross-vaccine spillovers to other age-appropriate vaccines. Our results further suggest that there was no difference in influenza vaccination coverage between the standard letter and the tailored letter that informed individuals about the social benefits of vaccination (0·2 pp, 95% CI: - 0·1 to 1·3). Interpretation: Sending information letters is an effective and easily scalable low-cost intervention strategy to increase vaccine uptake in an elderly population. Communicating the social benefits of vaccination in addition to individual benefits does not enhance influenza vaccine uptake. The effectiveness of behavioral interventions aiming to improve vaccination coverage crucially depends on the prior vaccination history of the target population. These findings have meaningful implications for public health authorities who implement vaccine communication strategies to enhance vaccine uptake and aim to curb the spread of infectious diseases.

10. Kinetics of Post-Vaccination Seroprotection to S. Pneumonia for the Immune-Compromised and Vaccine-Naïve Populations

Background S. pneumonia infection presents a significant challenge, accounting for 20–38% of hospital-acquired pneumonia, and the leading cause of community-acquired pneumonia despite availability of effective vaccines. Incidence is highest in children under 2 years, the immunocompromised, and elderly. CDC has reported the emergence of antibiotic resistance in ~30% of cases, adding to risk of morbidity and mortality. Fewer than half of the elderly are vaccinated and vulnerable to infection on admission. Passive immunotherapy as an adjunct to vaccines may improve outcomes in such populations. The objective of this study was to evaluate whether seroprotective response induced with a pneumococcal conjugate vaccine could rapidly yield protective opsonic levels of antibody within anticipated duration of hospitalization.MethodsHealthy donors (n=30) were immunized with Prevnar. Blood was drawn on days 0, 3, 7, 10, 14, 21, and 28. Samples were pooled and tested for presence of functional opsonic antibodies recognizing capsular polysaccharides. Clearance mechanism of S. pneumonia was based on antibody recognition to pneumococcal capsular polysaccharide and opsonic titers used as an in vitro surrogate to evaluate the efficacy of vaccine.ResultsThere was little to no opsonic activity against most serotypes on day 0, except for low antibody activity with serotypes 1, 3, 4, and 5. Titers increased, with protective levels achieved by day 10 for most serotypes (except 14 and 18C), peaking at day 14 or after across serotypes (Figures 1 and 2). Average titers rose from log2 titer 2 on day 0 to log2 titer 8 on days 21 and 28. Titers against most serotypes reached log2 10 (titer 1024) or higher. Patients remained susceptible to nosocomial infection for at least 10 days post admission until protective titers are reached.OPK titers (log2 scale) for serum samples on day 0 (pre), day 3, 7, 10, 14, 21, 28, and control for S. pneumoniae serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V. N=2. OPK titers (log2 scale) for serum samples on day 0 (pre), day 3, 7, 10, 14, 21, 28, and control for S. pneumoniae serotypes 14, 18C, 19A, 19F, and 23F. N=2. ConclusionPatients with no prior history of vaccination (or inability to mount response) with Prevnar or pneumovax remain vulnerable to S. pneumonia infection even if vaccinated on entry, due to delayed kinetics in reaching protective titers. These patients may require prophylactic intervention of hyperimmune Ig with high opsonic titers to S. pneumonia, providing protection until vaccine response elicits protective antibodies.Disclosures All Authors: No reported disclosures

Equine seroprevalence of West Nile virus antibodies in the UK in 2019

BackgroundWest Nile virus (WNV) is a single-stranded RNA virus that can cause neurological disease in both humans and horses. Due to the movement of competent vectors and viraemic hosts, WNV has repeatedly emerged globally and more recently in western Europe. Within the UK, WNV is a notifiable disease in horses, and vaccines against the virus are commercially available. However, there has been no investigation into the seroprevalence of WNV in the UK equine population to determine the extent of vaccination or to provide evidence of recent infection.MethodsEquine serum samples were obtained from the Animal and Plant Health Agency’s equine testing service between August and November 2019. A total of 988 serum samples were selected for horses resident in South East England. WNV seroprevalence was determined using two enzyme-linked immunosorbent assays (ELISAs) to detect total flavivirus antibodies and WNV-specific immunoglobulin M (IgM) antibodies. Positive IgM results were investigated by contacting the submitting veterinarian to establish the clinical history or evidence of prior vaccination of the horses in question.ResultsWithin the cohort, 274 samples tested positive for flavivirus antibodies, of which two subsequently tested positive for WNV-specific IgM antibodies. The follow-up investigation established that both horses had been vaccinated prior to serum samples being drawn, which resulted in an IgM-positive response. All the samples that tested positive by competition ELISA were from horses set to be exported to countries where WNV is endemic. Consequently, the positive results were likely due to previous vaccination. In contrast, 714 samples were seronegative, indicating that the majority of the UK equine population may be susceptible to WNV infection.ConclusionsThere was no evidence for cryptic WNV infection in a cohort of horses sampled in England in 2019. All IgM-seropositive cases were due to vaccination; this should be noted for future epidemiological surveys in the event of a disease outbreak, as it is not possible to distinguish vaccinated from infected horses without knowledge of their clinical histories.Graphical

Increasing healthcare workers’ uptake of seasonal influenza vaccination in a tertiary-care pediatric hospital in Greece with a low-cost, tailor-made, multifaceted strategy

BackgroundHealthcare workers’ (HCW) seasonal influenza vaccination (SIV) is critical to prevent nosocomial influenza. However, HCW vaccination rates remain unacceptably low in many European institutions. A two-year three-step initiative was implemented at a tertiary-care pediatric hospital with 750 beds in Athens, Greece with the aim of increasing SIV among HCW. MethodsΑ cross-sectional anonymous survey of HCWs was conducted during the 2015–16 influenza season with the aim to evaluate attitudes, knowledge, and specific barriers and facilitators for SIV. Stratified analysis was used to identify factors associated with no prior history of influenza vaccination. Multifaceted interventions were implemented in the 2016–2017 season. These included 1) education around influenza disease and SIV, and 2) communication of availability and opportunity (time and place) of SIV. Interventions were designed to target HCWs with the lowest SIV rates in the previous three years. ResultsWe achieved a 67% response rate, with 363 respondents (106 doctors, 145 nurses, 101 other hospital staff; 11 did not provide their profession). Most (64%) had not been vaccinated in the previous three years; only 14% received the vaccine annually. Non-vaccination rates were significantly higher among nurses (76%) and cleaning and food-service workers (73%) compared to doctors (40%) (P < 0.001). Protection of self, family, patients and colleagues were the most common motivations. Concerns about the safety and effectiveness of the vaccine, the belief that one does not belong to a high-risk group were the most common barriers. The interventions led to an increase in SIV uptake by the HCWs in the hospital, from 19% to 31%. ConclusionsIn a country with very low reported rates of vaccination among HCWs, a simple, low-cost, tailor-made intervention strategy can lead to an increase in SIV uptake. Stratifying data according to vaccination history may reveal a diversity of targets for improvement that might otherwise be missed.

Influenza Vaccine Effectiveness by A(H3N2) Phylogenetic Subcluster and Prior Vaccination History: 2016-2017 and 2017-2018 Epidemics in Canada.

BackgroundThe influenza A(H3N2) vaccine was updated from clade 3C.3a in 2015–2016 to 3C.2a for 2016–2017 and 2017–2018. Circulating 3C.2a viruses showed considerable hemagglutinin glycoprotein diversification and the egg-adapted vaccine also bore mutations.MethodsVaccine effectiveness (VE) in 2016–2017 and 2017–2018 was assessed by test-negative design, explored by A(H3N2) phylogenetic subcluster and prior season’s vaccination history.ResultsIn 2016–2017, A(H3N2) VE was 36% (95% confidence interval [CI], 18%–50%), comparable with (43%; 95% CI, 24%–58%) or without (33%; 95% CI, −21% to 62%) prior season’s vaccination. In 2017–2018, VE was 14% (95% CI, −8% to 31%), lower with (9%; 95% CI, −18% to 30%) versus without (45%; 95% CI, −7% to 71%) prior season’s vaccination. In 2016–2017, VE against predominant clade 3C.2a1 viruses was 33% (95% CI, 11%–50%): 18% (95% CI, −40% to 52%) for 3C.2a1a defined by a pivotal T135K loss of glycosylation; 60% (95% CI, 19%–81%) for 3C.2a1b (without T135K); and 31% (95% CI, 2%–51%) for other 3C.2a1 variants (with/without T135K). VE against 3C.2a2 viruses was 45% (95% CI, 2%–70%) in 2016–2017 but 15% (95% CI, −7% to 33%) in 2017–2018 when 3C.2a2 predominated. VE against 3C.2a1b in 2017–2018 was 37% (95% CI, −57% to 75%), lower at 12% (95% CI, −129% to 67%) for a new 3C.2a1b subcluster (n = 28) also bearing T135K.ConclusionsExploring VE by phylogenetic subcluster and prior vaccination history reveals informative heterogeneity. Pivotal mutations affecting glycosylation sites, and repeat vaccination using unchanged antigen, may reduce VE.