Reporting rates for VAERS death reports following COVID-19 vaccination, December 14, 2020-November 17, 2021

PURPOSE

Despite widely available safety information for the COVID-19 vaccines, vaccine hesitancy remains a challenge. In some cases, vaccine hesitancy may be related to concerns about the number of reports of death to the Vaccine Adverse Event Reporting System (VAERS). We aimed to provide information and context about reports of death to VAERS following COVID-19 vaccination.

METHODS

This is a descriptive study evaluating reporting rates for VAERS death reports for COVID-19 vaccine recipients in the United States between December 14, 2020, and November 17, 2021. Reporting rates were calculated as death events per million persons vaccinated and compared to expected all-cause (background) death rates.

RESULTS

9201 death events were reported for COVID-19 vaccine recipients aged 5 years and older (or age unknown). Reporting rates for death events increased with increasing age, and males generally had higher reporting rates than females. For death events within 7 days and 42 days of vaccination, respectively, observed reporting rates were lower than the expected all-cause death rates. Reporting rates for Ad26.COV2.S vaccine were generally higher than for mRNA COVID-19 vaccines, but still lower than the expected all-cause death rates. Limitations of VAERS data include potential reporting bias, missing or inaccurate information, lack of a control group, and reported diagnoses, including deaths, are not causally verified diagnoses.

CONCLUSIONS

Reporting rates for death events were lower than the all-cause death rates expected in the general population. Trends in reporting rates reflected known trends in background death rates. These findings do not suggest an association between vaccination and overall increased mortality.

The risk of febrile seizures following influenza and 13-valent pneumococcal conjugate vaccines

BACKGROUND

Evidence on the risk of febrile seizures after inactivated influenza vaccine (IIV) and 13-valent pneumococcal conjugate vaccine (PCV13) is mixed. In the FDA-sponsored Sentinel Initiative, we examined risk of febrile seizures after IIV and PCV13 in children 6-23 months of age during the 2013-14 and 2014-15 influenza seasons.

METHODS

Using claims data and a self-controlled risk interval design, we compared the febrile seizure rate in a risk interval (0-1 days) versus control interval (14-20 days). In exploratory analyses, we assessed whether the effect of IIV was modified by concomitant PCV13 administration.

RESULTS

Adjusted for age, calendar time and concomitant administration of the other vaccine, the incidence rate ratio (IRR) for risk of febrile seizures following IIV was 1.12 (95% CI 0.80, 1.56) and following PCV13 was 1.80 (95% CI 1.29, 2.52). The attributable risk for febrile seizures following PCV13 ranged from 0.33 to 5.16 per 100,000 doses by week of age. The age and calendar-time adjusted IRR comparing exposed to unexposed time was numerically larger for concomitant IIV and PCV13 (IRR 2.80, 95% CI 1.63, 4.83), as compared to PCV13 without concomitant IIV (IRR 1.54, 95% CI 1.04, 2.28), and the IRR for IIV without concomitant PCV13 suggested no independent effects of IIV (IRR 0.94, 95% CI 0.63, 1.42). Taken together, this suggests a possible interaction between IIV and PCV13, though our study was not sufficiently powered to provide a precise estimate of the interaction.

CONCLUSIONS

We found an elevated risk of febrile seizures after PCV13 vaccine but not after IIV. The risk of febrile seizures after PCV13 is low compared to the overall risk in this population of children, and the risk should be interpreted in the context of the importance of preventing pneumococcal infections.

Meeting report narcolepsy and pandemic influenza vaccination: What we know and what we need to know before the next pandemic? A report from the 2nd IABS meeting

A group of scientific and public health experts and key stakeholders convened to discuss the state of knowledge on the relationship between adjuvanted monovalent inactivated 2009 influenza A H1N1 vaccines used during the 2009 influenza pandemic and narcolepsy. There was consensus that an increased risk of narcolepsy was consistently observed after Pandemrix (AS03-adjuvanted) vaccine, but similar associations following Arepanrix (AS03-adjuvanted) or Focetria (MF59-adjuvanted) vaccines were not observed. Whether the differences are due to vaccine composition or other factors such as the timing of large-scale vaccination programs relative to H1N1pdm09 wild-type virus circulation in different geographic regions is not clear. The limitations of retrospective observational methodologies could also be contributing to some of the differences across studies. More basic and epidemiologic research is needed to further elucidate the association between adjuvanted influenza vaccine and narcolepsy and its mechanism and to inform planning and preparation for vaccination programs in advance of the next influenza pandemic.

Post-licensure safety surveillance of zoster vaccine live (Zostavax®) in the United States, Vaccine Adverse Event Reporting System (VAERS), 2006-2015

BACKGROUND

Herpes zoster (HZ), or shingles, is caused by reactivation of varicella-zoster virus in latently infected individuals. Live-attenuated HZ vaccine (zoster vaccine live, ZVL) is approved in the United States for persons aged ≥50 years and recommended by the CDC for persons ≥60 years.

METHODS

We analyzed U.S. reports of adverse events (AEs) following ZVL submitted to the Vaccine Adverse Event Reporting System (VAERS), a spontaneous reporting system to monitor vaccine safety, for persons vaccinated May 1, 2006, through January 31, 2015. We conducted descriptive analysis, clinical reviews of reports with selected pre-specified conditions, and empirical Bayesian data mining.

RESULTS

VAERS received 23,092 reports following ZVL, of which 22,120 (96%) were classified as non-serious. Of reports where age was documented (n = 18,817), 83% were in persons aged ≥60 years. Reporting rates of AEs were 106 and 4.4 per 100,000 ZVL doses distributed for all reports and serious reports, respectively. When ZVL was administered alone among persons aged ≥50 years, injection site erythema (27%), HZ (17%), injection site swelling (17%), and rash (14%) were the most commonly reported symptoms among non-serious reports; HZ (29%), pain (18%), and rash (16%) were the most commonly reported symptoms among serious reports. Six reports included laboratory evidence of vaccine-strain varicella-zoster virus (Oka/Merck strain) infection; AEs included HZ, HZ- or varicella-like illness, and local reaction with vesicles. In our review of reports of death with sufficient information to determine cause (n = 46, median age 75 years), the most common causes were heart disease (n = 28), sepsis (n = 4), and stroke (n = 3). Empirical Bayesian data mining did not detect new or unexpected safety signals.

CONCLUSIONS

Findings from our safety review of ZVL are consistent with those from pre-licensure clinical trials and other post-licensure assessments. Transient injection-site reactions, HZ, and rashes were most frequently reported to VAERS following ZVL. Overall, our results are reassuring regarding the safety of ZVL.

Effectiveness and Duration of Protection Provided by the Live-attenuated Herpes Zoster Vaccine in the Medicare Population Ages 65 Years and Older

Background

Tens of millions of seniors are at risk of herpes zoster (HZ) and its complications. Live attenuated herpes zoster vaccine (HZV) reduces that risk, although questions regarding effectiveness and durability of protection in routine clinical practice remain. We used Medicare data to investigate HZV effectiveness (VE) and its durability.

Methods

This retrospective cohort study included beneficiaries ages ≥65 years during January 2007 through July 2014. Multiple adjustments to account for potential bias were made. HZV-vaccinated beneficiaries were matched to unvaccinated beneficiaries (primary analysis) and to HZV-unvaccinated beneficiaries who had received pneumococcal vaccination (secondary analysis). HZ outcomes in community and hospital settings were analyzed, including ophthalmic zoster (OZ) and postherpetic neuralgia (PHN).

Results

Among eligible beneficiaries (average age 77 years), the primary analysis found VE for community HZ of 33% (95% CI: 32%-35%) and 19% (95% CI: 17%-22%), for the first 3, and subsequent 4+ years postvaccination, respectively. In the secondary analysis, VE was, respectively, 37% (95% CI: 36%-39%) and 22% (95% CI: 20%-25%). In the primary analysis, VE for PHN was 57% (95% CI: 52%-61%) and 45% (95% CI: 36%-53%) in the first 3 and subsequent 4+ years, respectively; VE for hospitalized HZ was, respectively, 74% (95% CI: 67%-79%) and 55% (95% CI: 39%-67%). Differences in VE by age group were not significant.

Conclusions

In both the primary and secondary analyses, HZV provided protection against HZ across all ages, but effectiveness declined over time. VE was higher and better preserved over time for PHN and HZ-associated hospitalizations than for community HZ.

Reports of Postural Orthostatic Tachycardia Syndrome After Human Papillomavirus Vaccination in the Vaccine Adverse Event Reporting System

PURPOSE

Human papillomavirus (HPV) vaccination prevents infections with HPV strains that cause certain cancers. Reports of postural orthostatic tachycardia syndrome (POTS) following HPV vaccination have raised safety concerns. We reviewed POTS reports submitted to the Vaccine Adverse Event Reporting System (VAERS).

METHODS

We searched the VAERS database for reports of POTS following any type of HPV vaccination (bivalent, quadrivalent, or nonavalent) from June 2006 to August 2015. We reviewed reports and applied established POTS diagnostic criteria. We calculated unadjusted POTS case reporting rates based on HPV vaccine doses distributed and conducted empirical Bayesian data mining to screen for disproportional reporting of POTS following HPV vaccination.

RESULTS

Among 40,735 VAERS reports following HPV vaccination, we identified 29 POTS reports that fully met diagnostic criteria. Of these, 27 (93.1%) were in females and mean age was 14 years (range 12-32). Median time from vaccination to start of symptoms was 43 days (range 0-407); most (18, 75.0%) had onset between 0 and 90 days. Symptoms frequently reported concomitantly included headache (22, 75.9%) and dizziness (21, 72.4%). Twenty (68.9%) reports documented a history of pre-existing medical conditions, of which chronic fatigue (5, 17.2%), asthma (4, 13.8%), and chronic headache (3, 10.3%) were most common. Approximately one POTS case is reported for every 6.5 million HPV vaccine doses distributed in the United States. No empirical Bayesian data mining safety signals for POTS and HPV vaccination were detected.

CONCLUSIONS

POTS is rarely reported following HPV vaccination. Our review did not detect any unusual or unexpected reporting patterns that would suggest a safety problem.

Postmarketing safety surveillance of trivalent recombinant influenza vaccine: Reports to the Vaccine Adverse Event Reporting System

On January 16, 2013, the Food and Drug Administration approved recombinant hemagglutinin influenza vaccine (RIV3) (Spodoptera frugiperda cell line; Flublok), which is the first completely egg-free flu vaccine licensed in the United States. To improve our understanding of the safety profile of this vaccine, we reviewed and summarized reports to the Vaccine Adverse Event Reporting System (VAERS) following RIV3. Through June 30, 2016, VAERS received 88 reports. Allergic reactions, including anaphylaxis, were the most common type of adverse event. Based on medical review, 10 cases met the Brighton Collaboration case definition of anaphylaxis, 21 reports described allergic reactions other than anaphylaxis, and 11 reports described signs and symptoms that suggested hypersensitivity. Other adverse events included injection site reactions, fatigue, myalgia, headache, and fever. The occurrence of anaphylaxis and other allergic reactions in some individuals may reflect an underlying predisposition to atopy that may manifest itself after an exposure to any drug or vaccine, and it does not necessarily suggest a causal relationship with the unique constituents that are specific to the vaccine product administered. Further research may elucidate the mechanism of allergic reactions following influenza vaccination: it is possible that egg proteins and influenza hemagglutinin play little or no role. Vaccination remains the single best defense against influenza and its complications. The information summarized here may enable policy makers, health officials, clinicians, and patients to make a more informed decision regarding vaccination strategies.

Post-licensure surveillance of quadrivalent inactivated influenza (IIV4) vaccine in the United States, Vaccine Adverse Event Reporting System (VAERS), July 1, 2013-May 31, 2015

BACKGROUND

Quadrivalent inactivated influenza vaccines (IIV4) were first available for use during 2013-14 influenza season for individuals aged ≥6 months. IIV4 is designed to protect against four different flu viruses; two influenza A viruses and two influenza B viruses.

METHODS

We searched the Vaccine Adverse Event Reporting System (VAERS) for US reports after IIV4 and trivalent inactivated influenza vaccine (IIV3) from 7/1/2013-5/31/2015. Medical records were requested for non-manufacturer reports classified as serious (i.e. death, hospitalization, prolonged hospitalization, life-threatening illness, permanent disability). The review included automated data analysis, clinical review of all serious reports, reports of special interest, and empirical Bayesian data mining.

RESULTS

VAERS received 1,838 IIV4 reports; 512 (28%) in persons aged 6 months-17 years of which 42 (8.2%) were serious reports; 1,265 (69%) in persons aged >18 years of which 84 (6.6%) were serious reports; two in children <6 months and 59 in persons of unknown age. Injection site erythema (24%), fever (14%) and injection site swelling (17%) were the most frequent adverse events among persons aged 6 months-17 years, while injection site pain (16%), pain (15%) and pain in extremity (13%) were the most frequent among persons aged 18-64 years given the vaccine alone. Among non-death serious reports, injection site reactions, constitutional symptoms, Guillain-Barré syndrome, seizures, and anaphylaxis were the most frequently reported adverse events. Data mining detected disproportional reporting for incorrect vaccine administration with no associated adverse events. Adverse events following IIV4 reported to VAERS were similar to those following IIV3.

CONCLUSIONS

In our review of VAERS reports, IIV4 had a similar safety profile to IIV3. Most of the reported AEs were non-serious. Our findings are consistent with data from pre-licensure studies of IIV4.

Complementary use of passive surveillance and Mini-Sentinel to better characterize hemolysis after immune globulin

BACKGROUND

Hemolysis after intravenous immune globulins (IGIVs) is a known complication, but expanding indications and recent manufacturing changes warrant ongoing postmarketing surveillance. Characterization of post-IGIV hemolysis to date has been limited to small case series.

STUDY DESIGN AND METHODS

We queried the Food and Drug Administration's (FDA) Adverse Event Reporting System (FAERS) from 2007 to 2014. All reported post-IGIV hemolysis cases were classified using a prespecified case definition and a case series analysis performed. We also conducted two assessments using FDA's Mini-Sentinel (MS) system to quantify the risk of hemolysis by six product indications and by IGIV formulation and evaluate the onset interval.

RESULTS

A total of 109 FAERS cases met our definition. For cases with available information, 83% (66/80) received IGIV doses of at least 2 g/kg, 98.1% (51/52) had non-O blood group, and 75% (64/85) of events occurred within 4 days of IGIV exposure. We identified 313,045 treatment episodes and 337 post-IGIV hemolytic events in MS from 2006 to 2014, with 72% occurring within 2 days. Rates of hemolysis were highest among patients with Kawasaki disease (KD) and immune thrombocytopenia (ITP). The risk among patients receiving nonlyophilized products was 2.3 times higher than that in patients receiving lyophilized products.

CONCLUSION

With the largest case series to date, FAERS data support that higher doses and non-O blood group are key risk factors. The incident rate of post-IGIV hemolysis is estimated at one per 1000 IGIV treatment episodes, with most occurring within 2 days of exposure. The risk is higher in patients with KD and ITP and after receipt of nonlyophilized IGIV.

Adverse events following Haemophilus influenzae type b vaccines in the Vaccine Adverse Event Reporting System, 1990-2013

OBJECTIVE

To characterize adverse events (AEs) after Haemophilus influenzae type b (Hib) vaccines reported to the US Vaccine Adverse Event Reporting System (VAERS), a spontaneous reporting surveillance system.

STUDY DESIGN

We searched VAERS for US reports after Hib vaccines among reports received from January 1, 1990, to December 1, 2013. We reviewed a random sample of reports and accompanying medical records for reports classified as serious. All reports of death were reviewed. Physicians assigned a primary clinical category to each reviewed report. We used empirical Bayesian data mining to identify AEs that were disproportionally reported after Hib vaccines.

RESULTS

VAERS received 29,747 reports after Hib vaccines; 5179 (17%) were serious, including 896 reports of deaths. Median age was 6 months (range 0-1022 months). Sudden infant death syndrome was the stated cause of death in 384 (51%) of 749 death reports with autopsy/death certificate records. The most common nondeath serious AE categories were neurologic (80; 37%), other noninfectious (46; 22%) (comprising mainly constitutional signs and symptoms); and gastrointestinal (39; 18%) conditions. No new safety concerns were identified after clinical review of reports of AEs that exceeded the data mining statistical threshold.

CONCLUSION

Review of VAERS reports did not identify any new or unexpected safety concerns for Hib vaccines.

Viruses and vitamin D in the etiology of type 1 diabetes mellitus and multiple sclerosis

Although specific viruses have been associated with autoimmune diseases, none fulfill Koch's criteria of causation. The etiologies of such diseases appear to be complex and multifactorial. For example, one might propose that the etiology of type 1 diabetes mellitus results from a toxic metabolite of nitrosamines during an enteroviral infection. Multiple sclerosis might result from a cascade of events involving several herpes virus infections activated during periods of vitamin D deficiency. We encourage investigators to consider Rotman's sufficient-component causal model when developing hypotheses for testing for the etiology of chronic diseases. Delineating the web of causation may lead to additional strategies for prevention and treatment of several autoimmune diseases.

Attrition of Military Enlistees with a Medical Waiver for Chronic Headache, 1995–2000

BACKGROUND

Recurrent headaches are disqualifying for military service if they are of sufficient severity or frequency to interfere with normal function in the past 3 years. The occupational impact of waiving this standard is evaluated.

METHODS

A retrospective cohort study of enlistees from January 1, 1995, through December 31, 2000, was performed. Enlistees with a waiver for recurrent headaches were compared with fully qualified enlistees (matched 3:1) for retention in the military, headache-related discharges, and hospitalizations.

RESULTS

The 174 individuals with waivers for a history of recurrent headaches were retained on active duty at the same rate as the 522 matched control subjects (log rank test, p = 0.91). Medical record review of waivers documented no debilitating headaches within 1 year before the medical examination.

CONCLUSIONS

These results validate the current headache waiver criteria from the perspective of retention and suggest a more lenient medical accession standard. Future studies should evaluate the morbidity and occupational impact of headaches in the U.S. military.

An Assessment of Universal versus Risk-Based Hepatitis C Virus Testing of Source Patients Postexposure to Blood and Body Fluids Among Healthcare Workers

OBJECTIVE

The objective of this study was to assess the impact of universal versus risk-based hepatitis C (HCV) testing of source patients' (SPs) postexposure to blood and body fluids on the HCV exposure rates among healthcare workers.

METHODS

Exposure and test result information between 1993 and 2004 was abstracted from the Johns Hopkins Bloodborne Pathogen Database. A Poisson regression model estimating HCV infection among underlying SPs based on partial testing was developed and applied.

RESULTS

After adjusting for the effect of partial testing of SPs, the estimated underlying prevalence of HCV-positive SPs increased slightly during the study period, from 11.9% to 15.1%, but the trend was not statistically significant. Yield curve of HCV-positive SPs rose quickly when SPs' testing rates were low but became flat when SPs' testing rates were high.

CONCLUSION

Reliance on HCV risk factors to screen SPs resulted in an underestimation of the prevalence of HCV in SPs before 1997 when the testing rates were between 15.4% and 25.6%. When SPs' testing rates were above 65%, our model predicted no additional yield of HCV-positive SPs.