Overview of U.S. COVID-19 vaccine safety surveillance systems.

The U.S. COVID-19 vaccination program, which commenced in December 2020, has been instrumental in preventing morbidity and mortality from COVID-19 disease. Safety monitoring has been an essential component of the program. The federal government undertook a comprehensive and coordinated approach to implement complementary safety monitoring systems and to communicate findings in a timely and transparent way to healthcare providers, policymakers, and the public. Monitoring involved both well-established and newly developed systems that relied on both spontaneous (passive) and active surveillance methods. Clinical consultation for individual cases of adverse events following vaccination was performed, and monitoring of special populations, such as pregnant persons, was conducted. This report describes the U.S. government's COVID-19 vaccine safety monitoring systems and programs used by the Centers for Disease Control and Prevention, the U.S. Food and Drug Administration, the Department of Defense, the Department of Veterans Affairs, and the Indian Health Service. Using the adverse event of myocarditis following mRNA COVID-19 vaccination as a model, we demonstrate how the multiple, complementary monitoring systems worked to rapidly detect, assess, and verify a vaccine safety signal. In addition, longer-term follow-up was conducted to evaluate the recovery status of myocarditis cases following vaccination. Finally, the process for timely and transparent communication and dissemination of COVID-19 vaccine safety data is described, highlighting the responsiveness and robustness of the U.S. vaccine safety monitoring infrastructure during the national COVID-19 vaccination program.

JYNNEOS vaccine safety surveillance during the 2022 mpox outbreak using the Vaccine Adverse Event Reporting System (VAERS) and v-safe, United States, 2022-2023.

BACKGROUND: In response to the 2022 mpox outbreak in the United States, people with higher potential for exposure to mpox were recommended to receive two doses of the JYNNEOS vaccine. Vaccine safety was monitored using two complementary systems. METHODS: The Vaccine Adverse Event Reporting System (VAERS) is a passive surveillance system that accepts reports of adverse events following 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 1,927 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 following 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.

Safety monitoring of bivalent mRNA COVID-19 vaccine among pregnant persons in the vaccine adverse event reporting System - United States, September 1, 2022 - March 31, 2023.

BACKGROUND: Pregnant persons are at increased risk of severe COVID-19 illness. Bivalent mRNA COVID-19 vaccination is recommended for everyone, including pregnant persons. However, data are limited on the safety of bivalent mRNA COVID-19 vaccination during pregnancy. OBJECTIVE: To evaluate and summarize reports to the Vaccine Adverse Event Reporting System (VAERS), a national spontaneous reporting system, among pregnant persons who received bivalent mRNA COVID-19 vaccine. METHODS: VAERS U.S. reports of adverse events (AEs) in pregnant persons who received the bivalent mRNA COVID-19 vaccine from 9/1/2022-03/31/2023 were identified. Clinicians reviewed all reports and available medical records. AEs of these reports were compared with AEs reported to VAERS following monovalent mRNA COVID-19 booster vaccination in pregnancy. RESULTS: VAERS received 136 reports for pregnant persons who received bivalent mRNA COVID-19 vaccine; 87 (64 %) after BNT162b2 (Pfizer-BioNTech), and 48 (35 %) after mRNA-1273 (Moderna); 28 (20.6 %) reports were classified as serious. The most common pregnancy-specific outcomes reported included 12 (8.8 %) spontaneous abortions (<20 weeks gestation), 6 (4.4 %) episodes of preterm delivery, and 5 (3.7 %) reports of preeclampsia. One stillbirth (≥20 weeks gestation) was reported. No maternal or infant deaths were reported. There were 6 reports of AEs in infants, which included 3 reports of admissions to the neonatal intensive care unit: two infants with low birth weight, and one infant with a patent ductus arteriosus and patent foramen ovale. Non-pregnancy-specific adverse events were mostly COVID-19 infection and systemic reactions (e.g., headache, fatigue). Pregnancy-specific conditions were reported less frequently after bivalent mRNA COVID-19 vaccination compared to monovalent mRNA COVID-19 booster vaccination (3rd and 4th dose). CONCLUSIONS: Based on this review of reports to VAERS, the safety profile of bivalent mRNA COVID-19 vaccination in pregnant persons was comparable to that observed for monovalent mRNA COVID-19 booster vaccination (3rd and 4th dose) in pregnant persons.

Safety of Simultaneous Administration of Bivalent mRNA COVID-19 and Influenza Vaccines in the Vaccine Adverse Event Reporting System (VAERS).

INTRODUCTION: Bivalent mRNA coronavirus disease 2019 (COVID-19) vaccines may be simultaneously administered with other recommended vaccines, including seasonal influenza vaccines. However, few studies have evaluated the safety of co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines. OBJECTIVE: The aim was to describe reports to the Vaccine Adverse Event Reporting System (VAERS) after co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines. METHODS: We searched the VAERS database for reports of adverse events (AEs) following co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines during the period of September 1, 2022-March 31, 2023. We assessed the characteristics of these reports and described the most frequently reported AEs. Clinicians reviewed available medical records for reports of serious AEs and adverse events of special interest (AESI). RESULTS: During the period of 1 September 2022 through 31 March 2023, VAERS received 3689 reports of AEs following co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines. The median age of vaccinees was 59 years (interquartile range 39, 70 years); 342 reports (9.3%) were classified as serious. The most common AEs among non-serious reports were severe-acute-respiratory-syndrome-related coronavirus (SARS-CoV-2) infection (785, 23.5%), cough (592, 17.7%), and fatigue (568, 17.0%). The most common AEs among serious reports were Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection (88, 25.7%), dyspnea (81, 23.7%), and condition aggravated (55, 16.1%). DISCUSSION: Reports of AEs following co-administration of bivalent mRNA COVID-19 and seasonal influenza vaccines did not reveal any unusual or unexpected patterns of AEs. Increased reporting of certain events (e.g., COVID-19) was expected due to Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) reporting requirements. CDC and FDA will continue to monitor the safety of co-administration of mRNA COVID-19 and seasonal influenza vaccines.

Administration of the GSK Respiratory Syncytial Virus Vaccine to Pregnant Persons in Error.

The GSK and Pfizer respiratory syncytial virus (RSV) vaccines are both indicated for adults aged 60 years and older, but only the Pfizer product is approved for use in pregnancy to prevent RSV-associated lower respiratory tract disease in infants aged younger than 6 months. To assess for vaccine administration errors (ie, administration of the GSK RSV vaccine to pregnant persons) VAERS (Vaccine Adverse Event Reporting System), a U.S. passive reporting system, was searched for the time period from August 2023 to January 2024. A total of 113 reports of these administration errors were identified. Most reports (103, 91.2%) did not describe an adverse event. These administration errors are preventable with proper education and training and other preventive measures.

Pneumococcal Vaccine for Adults Aged ≥19 Years: Recommendations of the Advisory Committee on Immunization Practices, United States, 2023

his report compiles and summarizes all published recommendations from CDC's Advisory Committee on Immunization Practices (ACIP) for use of pneumococcal vaccines in adults aged ≥19 years in the United States. This report also includes updated and new clinical guidance for implementation from CDC. Before 2021, ACIP recommended 23-valent pneumococcal polysaccharide vaccine (PPSV23) alone (up to 2 doses), or both a single dose of 13-valent pneumococcal conjugate vaccine (PCV13) in combination with 1­3 doses of PPSV23 in series (PCV13 followed by PPSV23), for use in U.S. adults depending on age and underlying risk for pneumococcal disease. In 2021, two new pneumococcal conjugate vaccines (PCVs), a 15-valent and a 20-valent PCV (PCV15 and PCV20), were licensed for use in U.S. adults aged ≥18 years by the Food and Drug Administration. ACIP recommendations specify the use of either PCV20 alone or PCV15 in series with PPSV23 for all adults aged ≥65 years and for adults aged 19­64 years with certain underlying medical conditions or other risk factors who have not received a PCV or whose vaccination history is unknown. In addition, ACIP recommends use of either a single dose of PCV20 or ≥1 dose of PPSV23 for adults who have started their pneumococcal vaccine series with PCV13 but have not received all recommended PPSV23 doses. Shared clinical decision-making is recommended regarding use of a supplemental PCV20 dose for adults aged ≥65 years who have completed their recommended vaccine series with both PCV13 and PPSV23. Updated and new clinical guidance for implementation from CDC includes the recommendation for use of PCV15 or PCV20 for adults who have received PPSV23 but have not received any PCV dose. The report also includes clinical guidance for adults who have received 7-valent PCV (PCV7) only and adults who are hematopoietic stem cell transplant recipients.

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.

COVID-19 vaccine safety inquiries to the centers for disease control and prevention immunization safety office.

BACKGROUND: Following the authorization and recommendations for use of the U.S. COVID-19 vaccines, the Centers for Disease Control and Prevention (CDC)'s Immunization Safety Office (ISO) responded to inquiries and questions from public health officials, healthcare providers, and the general public on COVID-19 vaccine safety. METHODS: We describe COVID-19 vaccine safety inquiries, by topic, received and addressed by ISO from December 1, 2020-August 31, 2022. RESULTS: Of the 1978 COVID-19 vaccine-related inquiries received, 1655 specifically involved vaccine safety topics. The most frequently asked-about topics included deaths following vaccination, myocarditis, pregnancy, and reproductive health outcomes, understanding or interpreting data from the Vaccine Adverse Event Reporting System (VAERS), and thrombosis with thrombocytopenia syndrome. CONCLUSIONS: Inquiries about vaccine safety generally reflect issues that receive media attention. ISO will continue to monitor vaccine safety inquiries and provide accurate and timely information to healthcare providers, public health officials, and the general public.

Spontaneous reports of primary ovarian insufficiency after vaccination: A review of the vaccine adverse event reporting system (VAERS).

BACKGROUND: Since 2012, reports of primary ovarian insufficiency (POI) temporally associated with receipt of human papillomavirus (HPV) vaccine have been published leading to questions about a potential causal association. A Vaccine Safety Datalink study did not find an increased risk for POI after vaccination. We reviewed the Vaccine Adverse Event Reporting System (VAERS) to describe POI reports. METHODS: We searched VAERS, a U.S. passive surveillance system, for domestic POI reports received from 01/01/1990 to 12/31/2017 after any vaccination. The search used both Medical Dictionary for Regulatory Activity Preferred Terms and a text-based search for POI and its symptoms. All reports were reviewed, and the American College of Obstetricians and Gynecologists (ACOG) guidelines for POI diagnosis were applied. Data mining for disproportionate reporting was conducted. RESULTS: Six hundred fifty-two reports met the search criteria and clinical review identified 19 POI reports. Most reports (n = 16) were received between 2013 and 2017. The median age at vaccination was 14.5 years (range 10-25 years) and the median interval between first dose of vaccination and reporting the event to VAERS was 43 months (range 4-132 months; mean 59.6 months). Four reports met ACOG diagnostic criteria; one with an underlying cause (47XXX chromosomal abnormality) reported. Eleven reports documented menstrual irregularity ≥ 3 months; 5 had ≥ 1 laboratory test result used to diagnose POI. Eighteen of 19 reports described receipt of HPV vaccine with or without other vaccines. Other vaccines reported were meningococcal conjugate vaccine, hepatitis A, varicella and tetanus toxoid, reduced diphtheria toxoid and acellular pertussis. Disproportionate reporting was found for three relevant coding terms after HPV vaccination. CONCLUSIONS: POI is rarely reported to VAERS. Most reports contained limited diagnostic information and were submitted after published cases of POI following HPV vaccination. Results of our review do not suggest a safety concern.

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 of co-administration of mRNA COVID-19 and seasonal inactivated influenza vaccines in the vaccine adverse event reporting system (VAERS) during July 1, 2021-June 30, 2022.

BACKGROUND: COVID-19 vaccines may be co-administered with other recommended vaccines, including seasonal influenza vaccines. However, few studies have evaluated the safety of co-administration of mRNA COVID-19 and seasonal influenza vaccines. OBJECTIVE: To describe reports to the Vaccine Adverse Event Reporting System (VAERS) after co-administration of mRNA COVID-19 and seasonal influenza vaccines. METHODS: We searched the VAERS database for reports of adverse events (AEs) following co-administration of mRNA COVID-19 and seasonal influenza vaccines and following a first booster dose mRNA COVID-19 vaccine alone, during July 1, 2021-June 30, 2022. We assessed the characteristics of these reports and described the most frequently reported MedDRA preferred terms (PTs). Clinicians reviewed available medical records for serious reports and reports of adverse events of special interest (AESI) and categorized the main diagnosis by system organ class. RESULTS: From July 1, 2021 through June 30, 2022, VAERS received 2,449 reports of adverse events following co-administration of mRNA COVID-19 and seasonal influenza vaccines. Median age of vaccinees was 48 years (IQR: 31, 66); 387 (15.8%) were classified as serious. Most reports (1,713; 69.3%) described co-administration of a first booster dose of an mRNA COVID-19 vaccine with seasonal influenza vaccine. The most common AEs among non-serious reports were injection site reactions (193; 14.5%), headache (181; 13.6%), and pain (171; 12.8%). The most common AEs among reports classified as serious were dyspnea (38; 14.9%), COVID-19 infection (32; 12.6%), and chest pain (27; 10.6%). DISCUSSION: This review of reports to VAERS following co-administration of mRNA COVID-19 and seasonal influenza vaccines did not reveal any unusual or unexpected patterns of AEs. Increased reporting of certain events (e.g., COVID-19 disease) was expected. CDC will continue to monitor the safety of co-administration of mRNA COVID-19 and seasonal influenza vaccines, including co-administration involving bivalent mRNA COVID-19 booster vaccines that have been recommended for people ages ≥ 6 months in the United States.

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.

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 of Booster Doses of Coronavirus Disease 2019 (COVID-19) Vaccine in Pregnancy in the Vaccine Adverse Event Reporting System.

OBJECTIVE: To evaluate and summarize reports to the Vaccine Adverse Event Reporting System (VAERS), a national spontaneous reporting system, in pregnant people who received a booster dose of mRNA coronavirus disease 2019 (COVID-19) vaccine. METHODS: We searched VAERS for U.S. reports of adverse events in pregnant people who received a booster dose of an mRNA COVID-19 vaccine from September 22, 2021, to March 24, 2022. Clinicians reviewed reports and available medical records. RESULTS: The Vaccine Adverse Event Reporting System received 323 reports of adverse events in pregnant people who received a booster dose of COVID-19 vaccine; 178 (55.1%) after BNT162b2 from Pfizer-BioNTech and 145 (44.9%) after mRNA-1273 from Moderna. Seventy-two (22.3%) reports were coded as serious. One neonatal death was reported, but no maternal deaths occurred. Pregnancy-specific outcomes included 56 (17.3%) spontaneous abortions (before 20 weeks of gestation), eight (2.5%) episodes of vaginal bleeding, five (1.5%) stillbirths (at or after 20 weeks of gestation), four (1.2%) episodes of preeclampsia, and two (0.6%) preterm deliveries. Reporting rates for stillbirth and preterm delivery were below background rates. Ten instances of adverse events in neonates were reported, which included two reports of birth defects. Non-pregnancy-specific adverse events (n=207; 64.1%) were mostly systemic (eg, headache, fatigue) and local reactions and occurred in proportions comparable with those seen in pregnant people who received the primary COVID-19 vaccination series and reported to VAERS during the same period. CONCLUSION: Review of reports after a booster dose of mRNA COVID-19 vaccine in pregnant people in VAERS found their safety profile was comparable with that of published reports after primary COVID-19 vaccination in pregnant people.

Post-authorization surveillance of adverse events following COVID-19 vaccines in pregnant persons in the vaccine adverse event reporting system (VAERS), December 2020 - October 2021.

BACKGROUND: Pregnant persons are at increased risk of severe illness from COVID-19 infection, including intensive care unit admission, mechanical ventilation, and death compared with non-pregnant persons of reproductive age. Limited data are available on the safety of COVID-19 vaccines administered during and around the time of pregnancy. OBJECTIVE: To evaluate and summarize reports to the Vaccine Adverse Event Reporting System (VAERS), a national spontaneous reporting system, in pregnant persons who received a COVID-19 vaccine to assess for potential vaccine safety problems. METHODS: We searched VAERS for US reports of adverse events (AEs) in pregnant persons who received a COVID-19 vaccine from 12/14/2020-10/31/2021. Clinicians reviewed reports and available medical records. Crude reporting rates for selected AEs were calculated, and disproportional reporting was assessed using data mining methods. RESULTS: VAERS received 3,462 reports of AEs in pregnant persons who received a COVID-19 vaccine; 1,831 (52.9%) after BNT162b2, 1,350 (38.9%) after mRNA-1273, and 275 (7.9%) after Ad26.COV2.S. Eight maternal deaths and 12 neonatal deaths were reported. Six-hundred twenty-one (17.9%) reports were serious. Pregnancy-specific outcomes included: 878 spontaneous abortions (<20 weeks), 101 episodes of vaginal bleeding, 76 preterm deliveries (<37 weeks), 62 stillbirths (≥20 weeks), and 33 outcomes with birth defects. Crude reporting rates for preterm deliveries and stillbirths, as well as maternal and neonatal mortality rates were below background rates from published sources. No disproportional reporting for any AE was observed. CONCLUSIONS: Review of reports to VAERS following COVID-19 vaccines in pregnant persons did not identify any concerning patterns of maternal or infant-fetal outcomes.

Postmarketing safety surveillance of high-dose quadrivalent influenza vaccine: Reports to the Vaccine Adverse Event Reporting System.

On November 4, 2019, the Food and Drug Administration approved high-dose quadrivalent influenza vaccine (Fluzone High-Dose Quadrivalent; QIV-HD) for active immunization for the prevention of influenza disease in individuals 65 years of age and older. A prelicensure randomized, active-controlled, modified double-blind trial did not reveal any major differences in adverse events following QIV-HD versus Fluzone High-Dose (trivalent). To improve our understanding of the safety profile of QIV-HD, we reviewed and summarized reports of adverse events after QIV-HD to the Vaccine Adverse Event Reporting System (VAERS). From July 30, 2020 through June 30, 2021, VAERS received 2,122 reports after QIV-HD. The vast majority (2,018; 95.1%) were non-serious and included events that had been observed in the prelicensure clinical trial, such as injection site reactions, fever, headache, and nausea. The most common serious events included Guillain-Barré syndrome, cellulitis or other local reactions, constitutional signs/symptoms (e.g., fever), and cardiovascular events. Our review did not reveal any new safety concerns. This information may enable policy makers, health officials, clinicians, and patients to make a more informed decision regarding vaccination strategies.