Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons.

BACKGROUND: Many pregnant persons in the United States are receiving messenger RNA (mRNA) coronavirus disease 2019 (Covid-19) vaccines, but data are limited on their safety in pregnancy. METHODS: From December 14, 2020, to February 28, 2021, we used data from the "v-safe after vaccination health checker" surveillance system, the v-safe pregnancy registry, and the Vaccine Adverse Event Reporting System (VAERS) to characterize the initial safety of mRNA Covid-19 vaccines in pregnant persons. RESULTS: A total of 35,691 v-safe participants 16 to 54 years of age identified as pregnant. Injection-site pain was reported more frequently among pregnant persons than among nonpregnant women, whereas headache, myalgia, chills, and fever were reported less frequently. Among 3958 participants enrolled in the v-safe pregnancy registry, 827 had a completed pregnancy, of which 115 (13.9%) resulted in a pregnancy loss and 712 (86.1%) resulted in a live birth (mostly among participants with vaccination in the third trimester). Adverse neonatal outcomes included preterm birth (in 9.4%) and small size for gestational age (in 3.2%); no neonatal deaths were reported. Although not directly comparable, calculated proportions of adverse pregnancy and neonatal outcomes in persons vaccinated against Covid-19 who had a completed pregnancy were similar to incidences reported in studies involving pregnant women that were conducted before the Covid-19 pandemic. Among 221 pregnancy-related adverse events reported to the VAERS, the most frequently reported event was spontaneous abortion (46 cases). CONCLUSIONS: Preliminary findings did not show obvious safety signals among pregnant persons who received mRNA Covid-19 vaccines. However, more longitudinal follow-up, including follow-up of large numbers of women vaccinated earlier in pregnancy, is necessary to inform maternal, pregnancy, and infant outcomes.

JYNNEOS Vaccine Safety Surveillance During the 2022 Mpox Outbreak Using the Vaccine Adverse Event Reporting System and V-safe, United States, 2022 to 2023.

BACKGROUND: In response to the 2022 mpox outbreak in the United States, people with higher potential for exposure to mpox were recommended to receive 2 doses of the JYNNEOS vaccine. Vaccine safety was monitored using 2 complementary systems. METHODS: The Vaccine Adverse Event Reporting System (VAERS) is a passive surveillance system that accepts reports of adverse events after vaccination. VAERS is capable of rapidly identifying rare adverse events and unusual reporting patterns. Medical records were requested and reviewed for adverse events of special interest, including myocarditis. Adverse event reporting rates were calculated as the number of verified adverse event cases divided by the number of JYNNEOS doses administered. V-safe for mpox was a voluntary smartphone-based vaccine safety surveillance system that sent enrolled persons text messages linked to health surveys asking about reactions and health impact events occurring after vaccination. RESULTS: There were 1,207,056 JYNNEOS doses administered in the United States. VAERS received 1927 reports for JYNNEOS. The myocarditis reporting rate per million doses was 2.69 after dose 1 and 8.64 after dose 2. V-safe had 213 participants complete at least one health survey. Rates of injection site and systemic reactions were similar in the first week after dose 1 and dose 2. CONCLUSIONS: JYNNEOS vaccine safety surveillance findings from VAERS and v-safe did not identify any unexpected safety concerns. The VAERS reporting rate for myocarditis was similar to previously published population background rates.

Postmarketing Safety Surveillance of a Hexavalent Vaccine in the Vaccine Adverse Event Reporting System.

We assessed the safety of hexavalent vaccine diphtheria and tetanus toxoids and acellular pertussis, inactivated poliovirus, hepatitis b, and haemophilus influenzae b conjugate vaccine in the Vaccine Adverse Event Reporting System. Five hundred-one reports of adverse events (AEs) were identified; 21 (4.2%) were serious. Most frequently reported AEs were fever (10.2%) and injection site erythema (5.4%). AEs reported were consistent with findings from prelicensure studies.

Safety Monitoring of mRNA COVID-19 Vaccine Third Doses Among Children Aged 6 Months-5 Years - United States, June 17, 2022-May 7, 2023.

As of May 7, 2023, CDC's Advisory Committee on Immunization Practices (ACIP) recommends that all children aged 6 months-5 years receive at least 1 age-appropriate bivalent mRNA COVID-19 vaccine dose. Depending on their COVID-19 vaccination history and history of immunocompromise, these children might also need additional doses* (1-3). Initial vaccine safety findings after primary series vaccination among children aged 6 months-5 years showed that transient local and systemic reactions were common whereas serious adverse events were rare (4). To characterize the safety of a third mRNA COVID-19 vaccine dose among children aged 6 months-5 years, CDC reviewed adverse events and health surveys reported to v-safe, a voluntary smartphone-based U.S. safety surveillance system established by CDC to monitor health after COVID-19 vaccination (https://vsafe.cdc.gov/en/) and the Vaccine Adverse Event Reporting System (VAERS), a U.S. passive vaccine safety surveillance system co-managed by CDC and the Food and Drug Administration (FDA) (https://vaers.hhs.gov/) (5). During June 17, 2022-May 7, 2023, approximately 495,576 children aged 6 months-4 years received a third dose (monovalent or bivalent) of Pfizer-BioNTech vaccine and 63,919 children aged 6 months-5 years received a third dose of Moderna vaccine.† A third mRNA COVID-19 vaccination was recorded for 2,969 children in v-safe; approximately 37.7% had no reported reactions, and among those for whom reactions were reported, most reactions were mild and transient. VAERS received 536 reports after a third dose of mRNA COVID-19 vaccine for children in these age groups; 98.5% of reports were nonserious and most (78.4%) were classified as a vaccination error.§ No new safety concerns were identified. Preliminary safety findings after a third dose of COVID-19 vaccine for children aged 6 months-5 years are similar to those after other doses. Health care providers can counsel parents and guardians of young children that most reactions reported after vaccination with Pfizer-BioNTech or Moderna vaccine were mild and transient and that serious adverse events are rare.

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.

Safety Surveillance of Varicella Vaccines in the Vaccine Adverse Event Reporting System, United States, 2006-2020.

BACKGROUND: . The Vaccine Adverse Event Reporting System (VAERS) is the United States national passive vaccine safety surveillance system. We updated the data on the safety of single-antigen varicella vaccine (VAR) and assessed the safety of combination measles, mumps, rubella, and varicella vaccine (MMRV) licensed in the United States using VAERS data. METHODS: US VAERS reports received after administration of VAR and MMRV during 2006-2020 were identified. Reports were analyzed by vaccine type, age, seriousness, most common adverse events (AEs), and concomitant vaccines. We reviewed medical records of selected reports of AEs of special interest and conducted empirical Bayesian data mining to identify disproportionally reported AEs. RESULTS: During 2006-2020, approximately 132.8 million VAR doses were distributed; 40 684 reports were received in VAERS (30.6/100 000 doses distributed), with 4.1% classified as serious (1.3/100 000 doses distributed). Approximately 35.5 million MMRV doses were distributed; 13 325 reports were received (37.6/100 000 doses distributed) with 3.3% classified as serious (1.3/100 000 doses distributed). The most common adverse health events after both VAR and MMRV were injection site reactions (31% and 27%), rash (28% and 20%), and fever (12% and 14%), respectively. Vaccination errors accounted for 23% of reports after VAR administration and 41% after MMRV administration, but ≥95% of them did not describe an adverse health event. AEs associated with evidence of vaccine strain varicella-zoster virus (vVZV) infection included meningitis, encephalitis, herpes zoster, and 6 deaths (all in immunocompromised persons with contraindications for vaccination). No new or unexpected AE was disproportionally reported. CONCLUSIONS: No new or unexpected safety findings were detected for VAR and MMRV given as recommended, reinforcing the favorable safety profiles of these vaccines. Providers should obtain specimens for viral testing and strain-typing for serious AEs if they consider vVZV as the possible causative agent.

Safety Monitoring of JYNNEOS Vaccine During the 2022 Mpox Outbreak - United States, May 22-October 21, 2022.

JYNNEOS (Modified Vaccinia Ankara vaccine, Bavarian Nordic) is recommended in the United States for persons exposed to or at high risk for exposure to Monkeypox virus during the 2022 monkeypox (mpox) outbreak (1). JYNNEOS is a live, nonreplicating viral vaccine licensed for the prevention of smallpox and mpox in adults aged ≥18 years, administered as a 0.5-mL 2-dose series given 28 days apart by subcutaneous injection (2). On August 9, 2022, the Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for administration of 0.1 mL doses by intradermal injection for adults aged ≥18 years as a strategy to increase vaccine supply, and administration of 0.5 mL doses subcutaneously for persons aged <18 years (3). During May 22-October 21, 2022, a total of 987,294 JYNNEOS vaccine doses were administered in the United States. CDC has monitored JYNNEOS vaccine safety using the Vaccine Adverse Event Reporting System (VAERS) and the Vaccine Safety Datalink (VSD) for vaccine recipients of all ages, and through single-patient emergency Investigational New Drug (EIND) procedures for persons aged <18 years vaccinated before August 9, 2022. The most common adverse health events reported to VAERS for adults were nonserious and included injection site reactions, which was consistent with the prelicensure studies. Adverse health events were reported at similar rates for doses received by intradermal and subcutaneous administration. Serious adverse events were rare in adults, and no serious adverse events have been identified among persons aged <18 years. Overall, postlicensure and postauthorization surveillance to date support JYNNEOS vaccine safety.

Use of Tetanus Toxoid, Reduced Diphtheria Toxoid, and Acellular Pertussis Vaccines: Updated Recommendations of the Advisory Committee on Immunization Practices - United States, 2019.

Since 2005, a single dose of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine has been recommended by the Advisory Committee on Immunization Practices (ACIP) for adolescents and adults (1,2). After receipt of Tdap, booster doses of tetanus and diphtheria toxoids (Td) vaccine are recommended every 10 years or when indicated for wound management. During the October 2019 meeting of ACIP, the organization updated its recommendations to allow use of either Td or Tdap where previously only Td was recommended. These situations include decennial Td booster doses, tetanus prophylaxis when indicated for wound management in persons who had previously received Tdap, and for multiple doses in the catch-up immunization schedule for persons aged ≥7 years with incomplete or unknown vaccination history. Allowing either Tdap or Td to be used in situations where Td only was previously recommended increases provider point-of-care flexibility. This report updates ACIP recommendations and guidance regarding the use of Tdap vaccines (3).

Anaphylaxis after vaccination reported to the Vaccine Adverse Event Reporting System, 1990-2016.

BACKGROUND: Anaphylaxis, a rare and potentially life-threatening hypersensitivity reaction, can occur after vaccination. OBJECTIVE: We sought to describe reports of anaphylaxis after vaccination made to the Vaccine Adverse Event Reporting System (VAERS) during 1990-2016. METHODS: We identified domestic reports of anaphylaxis within VAERS using a combination of Medical Dictionary for Regulatory Activity queries and Preferred Terms. We performed a descriptive analysis, including history of hypersensitivity (anaphylaxis, respiratory allergies, and drug allergies) and vaccines given. We reviewed all serious reports and all nonserious reports with available medical records to determine if they met the Brighton Collaboration case definition for anaphylaxis or received a physician's diagnosis. RESULTS: During the analytic period, VAERS received 467,960 total reports; 828 met the Brighton Collaboration case definition or received a physician's diagnosis of anaphylaxis: 654 (79%) were classified as serious, and 669 (81%) had medical records available. Of 478 reports in children aged less than 19 years, 65% were male; childhood vaccines were most commonly reported. Of 350 reports in persons aged 19 years or greater, 80% were female, and influenza vaccines were most frequently reported. Overall, 41% of reports described persons with no history of hypersensitivity. We identified 8 deaths, 4 among persons with no history of hypersensitivity. CONCLUSION: Anaphylaxis after vaccination is rare in the United States and can occur among persons with no history of hypersensitivity. Most persons recover fully with treatment, but serious complications, including death, can occur.

Prevention of Pertussis, Tetanus, and Diphtheria with Vaccines in the United States: Recommendations of the Advisory Committee on Immunization Practices (ACIP).

This report compiles and summarizes all recommendations from CDC's Advisory Committee on Immunization Practices (ACIP) regarding prevention and control of tetanus, diphtheria, and pertussis in the United States. As a comprehensive summary of previously published recommendations, this report does not contain any new recommendations and replaces all previously published reports and policy notes; it is intended for use by clinicians and public health providers as a resource. ACIP recommends routine vaccination for tetanus, diphtheria, and pertussis. Infants and young children are recommended to receive a 5-dose series of diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccines, with one adolescent booster dose of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine. Adults who have never received Tdap also are recommended to receive a booster dose of Tdap. Women are recommended to receive a dose of Tdap during each pregnancy, which should be administered from 27 through 36 weeks' gestation, regardless of previous receipt of Tdap. After receipt of Tdap, adolescents and adults are recommended to receive a booster tetanus and diphtheria toxoids (Td) vaccine every 10 years to assure ongoing protection against tetanus and diphtheria.

Deaths Reported to the Vaccine Adverse Event Reporting System, United States, 1997-2013.

BACKGROUND: Vaccines are among the safest medical products in use today. Hundreds of millions of vaccinations are administered in the United States each year. Serious adverse reactions are uncommon. However, temporally associated deaths can occur following vaccination. Our aim was to characterize main causes of death among reports submitted to the US Vaccine Adverse Event Reporting System (VAERS), a spontaneous vaccine safety surveillance system. METHODS: We searched VAERS for US reports of death after any vaccination from 1 July 1997 through 31 December 2013. Available medical records, autopsy reports, and death certificates were reviewed to identify cause of death. RESULTS: VAERS received 2149 death reports, most (n = 1469 [68.4%]) in children. Median age was 0.5 years (range, 0-100 years); males accounted for 1226 (57%) reports. The total annual number of death reports generally decreased during the latter part of the study period. Most common causes of death among 1244 child reports with available death certificates/autopsy reports included sudden infant death syndrome (n = 544 [44%]), asphyxia (n = 74 [6.0%]), septicemia (n = 61 [4.9%]), and pneumonia (n = 57 [4.6%]). Among 526 adult reports, most common causes of death included diseases of the circulatory (n = 247 [46.9%]) and respiratory systems (n = 77 [14.6%]), certain infections and parasitic diseases (n = 62 [11.8%]), and malignant neoplasms (n = 20 [3.8%]). For child death reports, 79.4% received >1 vaccine on the same day. Inactivated influenza vaccine given alone was most commonly associated with death reports in adults (51.4%). CONCLUSIONS: No concerning pattern was noted among death reports submitted to VAERS during 1997-2013. The main causes of death were consistent with the most common causes of death in the US population.

Adverse Events Following Measles, Mumps, and Rubella Vaccine in Adults Reported to the Vaccine Adverse Event Reporting System (VAERS), 2003-2013.

BACKGROUND: Limited data exist on the safety of the measles, mumps, and rubella (MMR) vaccine in adults. We reviewed reports of adverse events (AEs) to the Vaccine Adverse Event Reporting System (VAERS) to assess safety in this previously understudied group. METHODS: VAERS is the national spontaneous vaccine safety surveillance system coadministered by the Centers for Disease Control and Prevention and the US Food and Drug Administration. We searched the VAERS database for US reports of adults aged ≥19 years who received the MMR vaccine from 1 January 2003 to 31 July 2013. We clinically reviewed reports and available medical records for serious AEs, pregnancy reports, and reports for selected prespecified outcomes. RESULTS: During this period, VAERS received 3175 US reports after MMR vaccine in adults. Of these, 168 (5%) were classified as serious, including 7 reports of death. Females accounted for 77% of reports. The most common signs and symptoms for all reports were pyrexia (19%), rash (17%), pain (13%), and arthralgia (13%). We did not detect any new safety findings in empirical Bayesian data mining. We identified 131 reports of MMR vaccine administered to a pregnant woman; the majority of these vaccinations were in the first trimester and in 83 (62%), no AE was reported. CONCLUSIONS: In our review of VAERS data, we did not detect any new or unexpected safety concerns for MMR vaccination in adults. We identified reports of pregnant women exposed to MMR, which is a group in whom the vaccine is contraindicated, suggesting the need for continued provider education on vaccine recommendations and screening.

Advanced Clinical Decision Support for Vaccine Adverse Event Detection and Reporting.

BACKGROUND: Reporting of adverse events (AEs) following vaccination can help identify rare or unexpected complications of immunizations and aid in characterizing potential vaccine safety signals. We developed an open-source, generalizable clinical decision support system called Electronic Support for Public Health-Vaccine Adverse Event Reporting System (ESP-VAERS) to assist clinicians with AE detection and reporting. METHODS: ESP-VAERS monitors patients' electronic health records for new diagnoses, changes in laboratory values, and new allergies following vaccinations. When suggestive events are found, ESP-VAERS sends the patient's clinician a secure electronic message with an invitation to affirm or refute the message, add comments, and submit an automated, prepopulated electronic report to VAERS. High-probability AEs are reported automatically if the clinician does not respond. We implemented ESP-VAERS in December 2012 throughout the MetroHealth System, an integrated healthcare system in Ohio. We queried the VAERS database to determine MetroHealth's baseline reporting rates from January 2009 to March 2012 and then assessed changes in reporting rates with ESP-VAERS. RESULTS: In the 8 months following implementation, 91 622 vaccinations were given. ESP-VAERS sent 1385 messages to responsible clinicians describing potential AEs. Clinicians opened 1304 (94.2%) messages, responded to 209 (15.1%), and confirmed 16 for transmission to VAERS. An additional 16 high-probability AEs were sent automatically. Reported events included seizure, pleural effusion, and lymphocytopenia. The odds of a VAERS report submission during the implementation period were 30.2 (95% confidence interval, 9.52-95.5) times greater than the odds during the comparable preimplementation period. CONCLUSIONS: An open-source, electronic health record-based clinical decision support system can increase AE detection and reporting rates in VAERS.

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.

Prevention and control of haemophilus influenzae type b disease: recommendations of the advisory committee on immunization practices (ACIP).

This report compiles and summarizes all recommendations from CDC's Advisory Committee on Immunization Practices (ACIP) regarding prevention and control of Haemophilus influenzae type b (Hib) disease in the United States. As a comprehensive summary of previously published recommendations, this report does not contain any new recommendations; it is intended for use by clinicians, public health officials, vaccination providers, and immunization program personnel as a resource. ACIP recommends routine vaccination with a licensed conjugate Hib vaccine for infants aged 2 through 6 months (2 or 3 doses, depending on vaccine product) with a booster dose at age 12 through 15 months. ACIP also recommends vaccination for certain persons at increased risk for Hib disease (i.e., persons who have early component complement deficiencies, immunoglobulin deficiency, anatomic or functional asplenia, or HIV infection; recipients of hematopoietic stem cell transplant; and recipients of chemotherapy or radiation therapy for malignant neoplasms). This report summarizes current information on Hib epidemiology in the United States and describes Hib vaccines licensed for use in the United States. Guidelines for antimicrobial chemoprophylaxis of contacts of persons with Hib disease also are provided.

Reports to the Vaccine Adverse Event Reporting System after hepatitis A and hepatitis AB vaccines in pregnant women.

OBJECTIVE: To characterize adverse events (AEs) after hepatitis A vaccines (Hep A) and hepatitis A and hepatitis B combination vaccine (Hep AB) in pregnant women reported to the Vaccine Adverse Event Reporting System (VAERS), a spontaneous reporting surveillance system. STUDY DESIGN: We searched VAERS for AEs reports in pregnant women who received Hep A or Hep AB from Jan. 1, 1996-April 5, 2013. Clinicians reviewed all reports and available medical records. RESULTS: VAERS received 139 reports of AEs in pregnant women; 7 (5.0%) were serious; no maternal or infant deaths were identified. Sixty-five (46.8%) did not describe any AEs. For those women whose gestational age was available, most were vaccinated during the first trimester, 50/60 (83.3%) for Hep A and 18/21 (85.7%) for Hep AB. The most common pregnancy-specific outcomes following Hep A or Hep AB vaccinations were spontaneous abortion in 15 (10.8%) reports, elective termination in 10 (7.2%), and preterm delivery in 7 (5.0%) reports. The most common nonpregnancy specific outcome was urinary tract infection and nausea/vomiting with 3 (2.2%) reports each. One case of amelia of the lower extremities was reported in an infant following maternal Hep A immunization. CONCLUSION: This review of VAERS reports did not identify any concerning pattern of AEs in pregnant women or their infants following maternal Hep A or Hep AB immunizations during pregnancy.

Postmenopausal Bleeding After Coronavirus Disease 2019 (COVID-19) Vaccination: Vaccine Adverse Event Reporting System.

We identified U.S. reports of postmenopausal bleeding in the VAERS (Vaccine Adverse Event Reporting System) between December 13, 2020, and December 13, 2021. Among 711,224 VAERS reports after coronavirus disease 2019 (COVID-19) vaccination, during our study period, we identified 554 presumptive postmenopausal bleeding reports; 434 were further classified as verified based on data abstracted from reports and medical records, when available. In the United States, by December 14, 2021, 58.8 million women aged 50 years or older had received at least one dose of a COVID-19 vaccine, corresponding to approximately seven verified VAERS postmenopausal bleeding reports per 1 million women aged 50 years or older who received a COVID-19 vaccine. Reports of postmenopausal bleeding after COVID-19 vaccination in VAERS were rare, and causes of postmenopausal bleeding based on medical record review were consistent with known causes of postmenopausal bleeding.