Myocarditis and pericarditis recovery following smallpox vaccine 2002-2016: A comparative observational cohort study in the military health system.

OBJECTIVES: (1) Characterize the initial clinical characteristics and long-term outcomes of smallpox vaccine-associated hypersensitivity myocarditis and pericarditis (MP) in United States service members. (2) Describe the process of case identification and adjudication using the 2003 CDC nationally defined myocarditis/pericarditis epidemiologic case definitions to include consideration of case-specific diversity and evolving evidence. BACKGROUND: Between 2002 and 2016, 2.546 million service members received a smallpox Vaccinia vaccine. Acute MP is associated with vaccinia, but the long-term outcomes have not been studied. METHODS: Records of vaccinia-associated MP reported to the Vaccine Adverse Event Reporting System by vaccination date were adjudicated using the 2003 MP epidemiologic case definitions for inclusion in a retrospective observational cohort study. Descriptive statistics of clinical characteristics, presentation, cardiac complications, and time course of clinical and cardiac recovery were calculated with comparisons by gender, diagnosis and time to recovery. RESULTS: Out of over 5000 adverse event reports, 348 MP cases who survived the acute illness, including 276 myocarditis (99.6% probable/confirmed) and 72 pericarditis (29.2% probable/confirmed), were adjudicated for inclusion in the long-term follow-up. Demographics included a median age of 24 years (IQR 21,30) and male predominance (96%). Compared to background military population, the myocarditis and pericarditis cohort had a higher percentage of white males by 8.2% (95% CI: 5.6, 10.0) and age <40 years by 4.2% (95% CI: 1.7,5.8). Long-term follow-up documented full recovery in 267/306 (87.3%) with 74.9% recovered in less than a year (median ~3 months). Among patients with myocarditis, the percentage who had a delayed time to recovery at time of last follow-up was 12.8% (95% CI: 2.1,24.7) higher in those with an acute left ventricular ejection fraction (EF) of ≤50% and 13.5% (95% CI: 2.4,25.7) higher in those with hypokinesis. Patient complications included 6 ventricular arrhythmias (2 received implanted defibrillators) and 14 with atrial arrhythmias (2 received radiofrequency ablation). Three of 6 patients (50%) diagnosed with cardiomyopathy had clinical recovery at their last follow-up date. CONCLUSIONS: Hypersensitivity myocarditis/pericarditis following the smallpox vaccine is associated with full clinical and functional ventricular recovery in over 87% of cases (74.9% <1 year). A minority of MP cases experienced prolonged or incomplete recovery beyond 1 year.

Cardiac Adverse Events Following COVID-19 Vaccination in Patients With Prior Vaccine-Associated Myocarditis.

Background: Limited information exists to guide shared clinical decision making on COVID-19 vaccination in persons with a prior history of vaccine-associated myocarditis, pericarditis, or myopericarditis (VAMP). The objective of this retrospective observational case series was to characterize cardiac outcomes within 30 days following receipt of 1 or more COVID-19 vaccinations during 2021 in US service members diagnosed with prior non-COVID-19 VAMP between 1998 and 2019. Methods: As part of the collaborative public health mission with the Centers for Disease Control and Prevention for enhanced vaccine adverse events surveillance, the Defense Health Agency Immunization Healthcare Division maintains a clinical database of service members and beneficiaries referred for suspected adverse events following immunizations. Cases in this database recorded between January 1, 2003, and February 28, 2022, were reviewed to identify individuals with prior VAMP who received a COVID-19 vaccine in 2021 and developed signs or symptoms suggestive of VAMP within 30 days following COVID-19 vaccination. Results: Before the COVID-19 pandemic, 431 service members had verified VAMP. Among these 431 patients, 179 had records that confirmed receipt of a COVID-19 vaccine in 2021. Of these 179 patients, 171 (95.5%) were male. Their median age was 39 years (range, 21-67) at the time of COVID-19 vaccination. Most (n = 172; 96.1%) experienced their original VAMP episode after receipt of the live replicating smallpox vaccine. Eleven patients experienced cardiac-suggestive symptoms (chest pain, palpitations, or dyspnea) within 30 days of COVID-19 vaccination. Four patients met the criteria for recurrent VAMP. Three men aged 49, 50, and 55 years developed myocarditis within 3 days of an mRNA COVID-19 vaccine. One 25-year-old man developed pericarditis within 4 days of receiving an mRNA vaccine. All 4 COVID-19 recurrent VAMP cases fully recovered with minimal supportive care within weeks (myocarditis) to months (pericarditis). Conclusions: As demonstrated by this case series, albeit rare, VAMP may reoccur after COVID-19 vaccination among patients who experienced cardiac injury after smallpox vaccination. The clinical characteristics and course of the 4 recurring cases were mild, appearing similar to the post-COVID-19 VAMP described in individuals without a history of VAMP. More research is warranted on factors that may predispose patients to vaccine-associated cardiac injury and which vaccine platforms or schedules may reduce the risk of recurrence among patients who have experienced these events.

Comparative frequency of specified adverse events following Vero cell culture-derived Japanese encephalitis and Vi capsular polysaccharide typhoid vaccines in U.S. military personnel, July 2011-August 2019.

Vero cell culture-derived Japanese encephalitis (JE) vaccine (JE-VC; Ixiaro) was approved in the United States in 2009. The previous JE vaccine, an inactivated mouse brain-derived vaccine, had been associated with rare, but serious, allergic and neurologic adverse events (AE). Studies and AE surveillance have supported JE-VC's safety, but one evaluation among military personnel found elevated hypersensitivity and neurologic AE rates. However, co-administration of multiple vaccines to some personnel might have affected results. We retrospectively compared rates of hypersensitivity and neurologic AEs within 28 days following vaccination of military personnel with JE-VC or parenteral Vi capsular polysaccharide typhoid vaccine administered without other vaccines from July 1, 2011, through August 31, 2019. Rates of most events were similar between the vaccines. Only delayed hypersensitivity reactions occurred more frequently following JE-VC (rate ratio: 4.2, 95 % CI 1.2-15.3; p = 0.03), but rates were low for both vaccines. These results support JE-VC's safety.

Enhanced safety surveillance study of ACAM2000 smallpox vaccine among US military service members.

OBJECTIVES: To evaluate the rates of myopericarditis (primary objective) and rates of cardiovascular and neurological adverse events (secondary objectives) in temporal association with ACAM2000® smallpox vaccine. METHODS: Observational cohort study conducted through monthly surveillance from 2009 to 2017 of electronic medical records of military service members (SM) for pre-specified cardiac and neurological International Classification of Diseases (ICD) codes reported in the 30 days following smallpox vaccination. ICD codes potentially predictive of myopericarditis and codes for encephalitis, Guillain-Barré syndrome, and sudden death were classified into Group 1. All other cardiovascular and neurological ICD codes were classified into Group 2. Medical records containing Group 1 codes were individually reviewed to confirm coding accuracy and to seek additional data in support of myopericarditis adjudication, which was performed by an independent clinical panel. Chart reviews were not performed for Group 2 codes, which were reported in aggregate only. RESULTS: 897,227 SM who received ACAM2000 smallpox vaccine and 450,000 SM who received Dryvax smallpox vaccine were included in the surveillance population. The rate of adjudicated myopericarditis among ACAM2000 smallpox vaccine recipients was 20.06/100,000 and was significantly higher for males (21.8/100,000) than females (8.5/100,000) and for those < 40 years of age (21.1/100,000) than for those 40 years or older (6.3/100,000). Overall rates for any cardiovascular event (Group 1 plus Group 2) were 113.5/100,000 for ACAM2000 vaccine and 439.3/100,000 for Dryvax vaccine; rate ratio, 0.26 (95% CI, 0.24-0.28). The rates of subjects with one or more defined neurological events were 2.12/100,000 and 1.11/100,000 for ACAM2000 and Dryvax vaccines respectively; rate ratio, 1.91 (95% CI, 0.71-5.10). CONCLUSIONS: Electronic records surveillance of the entire vaccinated SM population over a ten-year period found rates of myopericarditis, of defined neurological events, and of overall cardiac events that were consistent with those of prior passive surveillance studies involving Dryvax or ACAM2000 smallpox vaccines. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov NCT00927719.

Insufficient Anthrax Lethal Toxin Neutralization Is Associated with Antibody Subclass and Domain Specificity in the Plasma of Anthrax-Vaccinated Individuals.

Anthrax vaccine adsorbed (AVA) is a significant line of defense against bioterrorist attack from Bacillus anthracis spores. However, in a subset of individuals, this vaccine may produce a suboptimal quantity of anti-protective antigen (PA), antibodies that are poorly neutralizing, and/or antibody titers that wane over time, necessitating annual boosters. To study individuals with such poor responses, we examine the properties of anti-PA in a subset of vaccinated individuals that make significant quantities of antibody but are still unable to neutralize toxin. In this cohort, characterized by poorly neutralizing antibody, we find that increased IgG4 to IgG1 subclass ratios, low antibody avidity, and insufficient antibody targeting domain 4 associate with improper neutralization. Thus, future vaccines and vaccination schedules should be formulated to improve these deficiencies.

Adverse events following adenovirus type 4 and type 7 vaccine, live, oral in the Vaccine Adverse Event Reporting System (VAERS), United States, October 2011-July 2018.

BACKGROUND: In March 2011, the U.S. Food and Drug Administration licensed adenovirus type 4 and type 7 vaccine, live, oral (Barr Labs, Inc.) (adenovirus vaccine) for use in military personnel 17 through 50 years of age. The vaccine was first universally administered to U.S. military recruits in October 2011. We investigated adverse event (AE) reports following the adenovirus vaccine submitted to the Vaccine Adverse Event Reporting System (VAERS). METHODS: We searched the VAERS database for U.S. reports among persons who received adenovirus vaccine during October 2011 through July 2018 including participants in a military observational study. We reviewed all serious reports and accompanying medical records. We compared the proportion of serious reports in a proxy military recruit population and reviewed all reports of suspected allergic reactions following adenovirus vaccination. RESULTS: During the analytic period, VAERS received 100 reports following adenovirus vaccination; 39 (39%) were classified as serious and of these, 17 (44%) were from the observational study. One death was reported. Males accounted for 72% of reports. Median age of vaccinees was 19 years (range 17-32). The most frequently reported serious AEs were Guillain Barré syndrome (GBS) (n = 12) and anaphylaxis (n = 8); of these, two GBS and all the anaphylaxis reports were reported in the observational study. Reports documented concurrent receipt of multiple other vaccines (95%) and penicillin G (IM Pen G) or other antibiotics (50%). CONCLUSIONS: The reporting rate for serious AEs was higher than with other vaccines administered in the comparison military recruit population (39% vs 18%); however, we identified no unexpected or concerning pattern of adenovirus vaccine AEs. Co-administration of vaccines and IM Pen G was commonly reported in this military population. These exposures may have contributed to the GBS and anaphylaxis outcomes observed with the adenovirus vaccine. Future adenovirus vaccine safety studies in a population without these co-administrations would be helpful in clarifying the vaccine's safety profile.

Anthrax Vaccine Precipitated Induces Edema Toxin-Neutralizing, Edema Factor-Specific Antibodies in Human Recipients.

Edema toxin (ET), composed of edema factor (EF) and protective antigen (PA), is a virulence factor of Bacillus anthracis that alters host immune cell function and contributes to anthrax disease. Anthrax vaccine precipitated (AVP) contains low but detectable levels of EF and can elicit EF-specific antibodies in human recipients of AVP. Active and passive vaccination of mice with EF can contribute to protection from challenge with Bacillus anthracis spores or ET. This study compared humoral responses to ET in recipients of AVP (n = 33) versus anthrax vaccine adsorbed (AVA; n = 66), matched for number of vaccinations and time postvaccination, and further determined whether EF antibodies elicited by AVP contribute to ET neutralization. AVP induced higher incidence (77.8%) and titer (229.8 ± 58.6) of EF antibodies than AVA (4.2% and 7.8 ± 8.3, respectively), reflecting the reported low but detectable presence of EF in AVP. In contrast, PA IgG levels and ET neutralization measured using a luciferase-based cyclic AMP reporter assay were robust and did not differ between the two vaccine groups. Multiple regression analysis failed to detect an independent contribution of EF antibodies to ET neutralization in AVP recipients; however, EF antibodies purified from AVP sera neutralized ET. Serum samples from at least half of EF IgG-positive AVP recipients bound to nine decapeptides located in EF domains II and III. Although PA antibodies are primarily responsible for ET neutralization in recipients of AVP, increased amounts of an EF component should be investigated for the capacity to enhance next-generation, PA-based vaccines.

A prospective study of the incidence of myocarditis/pericarditis and new onset cardiac symptoms following smallpox and influenza vaccination.

BACKGROUND: Although myocarditis/pericarditis (MP) has been identified as an adverse event following smallpox vaccine (SPX), the prospective incidence of this reaction and new onset cardiac symptoms, including possible subclinical injury, has not been prospectively defined. PURPOSE: The study's primary objective was to determine the prospective incidence of new onset cardiac symptoms, clinical and possible subclinical MP in temporal association with immunization. METHODS: New onset cardiac symptoms, clinical MP and cardiac specific troponin T (cTnT) elevations following SPX (above individual baseline values) were measured in a multi-center prospective, active surveillance cohort study of healthy subjects receiving either smallpox vaccine or trivalent influenza vaccine (TIV). RESULTS: New onset chest pain, dyspnea, and/or palpitations occurred in 10.6% of SPX-vaccinees and 2.6% of TIV-vaccinees within 30 days of immunization (relative risk (RR) 4.0, 95% CI: 1.7-9.3). Among the 1081 SPX-vaccinees with complete follow-up, 4 Caucasian males were diagnosed with probable myocarditis and 1 female with suspected pericarditis. This indicates a post-SPX incidence rate more than 200-times higher than the pre-SPX background population surveillance rate of myocarditis/pericarditis (RR 214, 95% CI 65-558). Additionally, 31 SPX-vaccinees without specific cardiac symptoms were found to have over 2-fold increases in cTnT (>99th percentile) from baseline (pre-SPX) during the window of risk for clinical myocarditis/pericarditis and meeting a proposed case definition for possible subclinical myocarditis. This rate is 60-times higher than the incidence rate of overt clinical cases. No clinical or possible subclinical myocarditis cases were identified in the TIV-vaccinated group. CONCLUSIONS: Passive surveillance significantly underestimates the true incidence of myocarditis/pericarditis after smallpox immunization. Evidence of subclinical transient cardiac muscle injury post-vaccinia immunization is a finding that requires further study to include long-term outcomes surveillance. Active safety surveillance is needed to identify adverse events that are not well understood or previously recognized.

Humoral responses to independent vaccinations are correlated in healthy boosted adults.

BACKGROUND: Roughly half of U.S. adults do not receive recommended booster vaccinations, but protective antibody levels are rarely measured in adults. Demographic factors, vaccination history, and responses to other vaccinations could help identify at-risk individuals. We sought to characterize rates of seroconversion and determine associations of humoral responses to multiple vaccinations in healthy adults. METHODS: Humoral responses toward measles, mumps, tetanus toxoid, pertussis, hepatitis B surface antigen, and anthrax protective antigen were measured by ELISA in post-immunization samples from 1465 healthy U.S. military members. We examined the effects of demographic and clinical factors on immunization responses, as well as assessed correlations between vaccination responses. RESULTS: Subsets of boosted adults did not have seroprotective levels of antibodies toward measles (10.4%), mumps (9.4%), pertussis (4.7%), hepatitis B (8.6%) or protective antigen (14.4%) detected. Half-lives of antibody responses were generally long (>30 years). Measles and mumps antibody levels were correlated (r=0.31, p<0.001), but not associated with select demographic features or vaccination history. Measles and mumps antibody levels also correlated with tetanus antibody response (r=0.11, p<0.001). CONCLUSIONS: Vaccination responses are predominantly robust and vaccine specific. However, a small but significant portion of the vaccinated adult population may not have quantitative seroprotective antibody to common vaccine-preventable infections.

Military healthcare providers reporting of adverse events following immunizations to the vaccine adverse event reporting system.

OBJECTIVES: We studied military health care provider (HCP) practices regarding reporting of adverse events following immunization (AEFI). METHODS: A convenience sample of HCP was surveyed to assess familiarity with Vaccine Adverse Event Reporting System (VAERS), AEFI they were likely to report, methods used and preferred for reporting, and perceived barriers to reporting. We analyzed factors associated with HCP reporting AEFI to VAERS. RESULTS: A total of 547 surveys were distributed with 487 completed and returned for an 89% response rate. The percentage of HCP aware of VAERS (54%) varied by occupation. 47% of respondents identified knowledge of at least one AEFI with only 34% of these indicating that they had ever reported to VAERS. More serious events were more likely to be reported. Factors associated with HCP reporting AEFIs in bivariate analysis included HCP familiarity with filing a paper VAERS report, HCP familiarity with filing an electronic VAERS report, HCP familiarity with VAERS, and time spent on immunization tasks. In a multivariable analysis, only HCP familiarity with filing a paper VAERS report was statistically significant (Odds ratio = 115.3; p < 0.001). CONCLUSIONS: Specific educational interventions targeted to military HCP likely to see AEFIs but not currently filing VAERS reports may improve vaccine safety reporting practices.

Systemic inflammatory reaction after pneumococcal vaccine: a case series.

BACKGROUND: Fever, leukocytosis, and large local reactions following the pneumococcal polysaccharide vaccine (PS23) have been described only in isolated case reports in the adult literature. Such atypical reactions can pose difficulty to providers when determining management. Patients experiencing this noninfectious reaction may receive unnecessary treatment if the diagnosis of robust inflammatory response to the PS23 vaccine is not considered. OBSERVATIONS: This is a clinical case series of 5 adult patients who received the influenza and PS23 vaccines and experienced a cellulitis-like reaction, fever, and leukocytosis in the days following vaccination. Four of the five patients received the influenza and PS23 vaccines in the same arm. The patient who received the vaccines in opposite arms had the local findings in the arm that received the PS23 vaccine. All 5 patients sought care and 4 were admitted to the hospital for observation or treatment with intravenous antibiotics. CONCLUSIONS: This case series highlights potential side effects of the PS23 vaccine that are not well described in the adult literature. Antibiotics were not helpful in treating these patients' local and systemic symptoms. Patients with histories consistent with that highlighted in this case series may avoid antibiotics and hospitalization if their providers recognize these symptoms as a noninfectious reaction to the PS23 vaccine.

Myopericarditis following smallpox vaccination.

Myopericarditis has been a rare or unrecognized event after smallpox vaccinations with the New York City Board of Health strain of vaccinia virus (Dryvax; Wyeth Laboratories, Marietta, Pennsylvania). In this article, the authors report an attributable incidence of at least 140 clinical cases of myopericarditis per million primary smallpox vaccinations with this strain of vaccinia virus. Fifty-eight males and one female aged 21-43 years with confirmed or probable acute myopericarditis were detected following vaccination of 492,730 US Armed Forces personnel from December 15, 2002, through September 30, 2003. The cases were identified through sentinel reporting to military headquarters, active surveillance using the Defense Medical Surveillance System, or reports to the Vaccine Adverse Event Reporting System. The observed incidence (16.11/100,000) of myopericarditis over a 30-day observation window among 347,516 primary vaccinees was nearly 7.5-fold higher than the expected rate of 2.16/100,000 (95% confidence interval: 1.90, 2.34) among nonvaccinated, active-duty military personnel, while the incidence of 2.07/100,000 among 145,155 revaccinees was not statistically different from the expected background rate. The cases were predominantly male (58/59; 98.3%) and White (51/59; 86.4%), both statistically significant associations (p = 0.0147 and p = 0.05, respectively).

Incidence and follow-up of inflammatory cardiac complications after smallpox vaccination.

OBJECTIVES: The purpose of this study was to assess the follow-up of patients with vaccinia-associated myocarditis. BACKGROUND: With the threat of biological warfare, the U.S. Department of Defense resumed a program for widespread smallpox vaccinations on December 13, 2002. One-year afterwards, there has been a significant increase in the occurrence of myocarditis and pericarditis among those vaccinated. METHODS: Cases were identified through sentinel reporting to military headquarters, systematic surveillance, and spontaneous reports. RESULTS: A total of 540,824 military personnel were vaccinated with a New York City Board of Health strain of vaccinia from December 2002 through December 2003. Of these, 67 developed myopericarditis at 10.4 +/- 3.6 days after vaccination. The ST-segment elevation was noted in 57%, mean troponin on admission was 11.3+/- 22.7 ng/dl, and peak cardiac enzymes were noted within 8 h of presentation. On follow-up of 64 patients (96%) at a mean of 32 +/- 16 weeks, all patients had objective normalization of echocardiography, electrocardiography, laboratory testing, graded exercise testing, and functional status; 8 (13%) reported atypical, non-limiting persistent chest discomfort. CONCLUSIONS: Post-vaccinial myopericarditis should be considered in patients with chest pain within 30 days after smallpox vaccination. Normalization of echocardiography, electrocardiography, and treadmill testing is expected, and nearly all patients have resolution of chest pain on follow-up.