Vaccine Adverse Event Reporting System (VAERS) Publications | Vaccine Safety (2023)

Haber P, Moro PL, Ng C, Dores GM, Perez-Vilar S, Marquez PL, Cano M. Safety review of tetanus toxoid, reduced diphtheria toxoid, acellular pertussis vaccines (Tdap) in adults aged ≥ 65 years, Vaccine Adverse Event Reporting System (VAERS), United States, September 2010 – December 2018.external icon Vaccine. 2020 Feb 5;38(6):1476-1480. Epub 2019 Dec 28.

The Advisory Committee on Immunization Practices recommends vaccination in adults 65 years of age and older with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap). To date, few studies have assessed the safety of Tdap in this age group. Using the Vaccine Adverse Event Reporting System (VAERS), researchers analyzed reports of adverse events (AEs) following Tdap in adults 65 years and older. From September 2010 to December 2018, VAERS received 1,798 reports; 94% were classified as non-serious. The most common AEs were injection site redness (26%), pain (19%), and swelling (18%). Of 104 serious reports, 7 deaths were reported; none had evidence to suggest the vaccine caused the deaths. Serious non-death reports included nervous system disorders (35.1%; n=34) and infections (18.6%; n=18). Overall, the analysis did not identify any new safety concerns and is consistent with prior post-marketing observations and pre-licensure studies.

Su JR, Haber P, Ng CS, Marquez PL, Dores GM, Perez-Vilar S, Cano MV. Erythema multiforme, Stevens Johnson syndrome, and toxic epidermal necrolysis reported after vaccination, 1999-2017.external icon Vaccine. 2020 Feb 11;38(7): 1746-1752. Epub 2019 Dec 20.

While some dermatologic adverse events are common after vaccination (i.e. redness at the injection site), erythema multiforme (EM), Stevens Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), and SJS/TEN are rare. Since the last review of VAERS data for these conditions, over 37 new vaccines were approved for use in the United States. Of the 466,027 reports to VAERS during 1999–2017, researchers identified and reviewed 984 reports of EM, 89 of SJS, 6 of SJS/TEN, and 7 of TEN. Most reports of EM (91%) were non-serious; 52% of SJS and all reports of SJS/TEN and TEN were serious. Most reports (58%) occurred within 7 days after vaccination. Childhood vaccines were reported most often; 48% of reports were of children younger than 4 years. Of 6 reported deaths, 5 were exposed or potentially exposed to medications known to cause these conditions, and 1 had severe dehydration. Overall, reporting of these conditions after vaccination remained rare, with no new safety concerns identified.

Hibbs BF, Ng CS, Museru O, Moro PL, Marquez P, Woo EJ, Cano MV, Shimabukuro TT. Reports of atypical shoulder pain and dysfunction following inactivated influenza vaccine, Vaccine Adverse Event Reporting System (VAERS), 2010-2017.external icon Vaccine. 2020 Jan 29;38(5):1137-1143. Epub 2019 Nov 26.

Some case reports have suggested that if inactivated influenza vaccine (IIV) is improperly administered, shoulder dysfunction may occur. Researchers reviewed reports of adverse events (AEs) made to the Vaccine Adverse Event Reporting System (VAERS) following IIV from July 2010 to June 2017. During this time, approximately 996 million flu vaccine doses were distributed in the United States. Of the 59,230 reports submitted, 1,220 met analysis criteria of atypical shoulder pain and dysfunction starting within 48 hours following IIV and continuing for more than 1 week. The analysis suggests these reports were not common, averaging 2% of flu vaccine AEs reported each year; most were females (82.6%), median age was 52 years. While the cause of these cases is unknown, vaccines given improperly might be a factor. Proper vaccine administration education and training are preventive measures.

Shimabukuro TT, Su JR, Marquez PL, Mba-Jonas A, Arana JE, Cano MV. Safety of the 9-Valent Human Papillomavirus Vaccine.external icon Pediatrics 2019 Dec; 144(6). pii: e20191791. Epub 2019 Nov 18.

Gardasil 9 (human papillomavirus 9-valent vaccine, recombinant; 9vHPV) was approved in 2014 for females and males to protect against 9 types of human papillomavirus infections that can cause cancer. Researchers analyzed reports of adverse events (AEs) after 9vHPV to the Vaccine Adverse Event Reporting System (VAERS) from December 2014 to December 2017. During that time, approximately 28 million 9vHPV doses were distributed in the United States. Of the 7,244 reports received, 31% were female, nearly 22% were male, and 47% of reports did not identify gender. Over 97% of reports were classified as non-serious. There were 2 deaths reported; no information in the reports or medical records suggested the deaths were related to vaccination. Overall, the analysis revealed no new or unexpected safety concerns. The 9vHPV safety profile is consistent with pre-licensure clinical trial data, and with the post-marketing safety data of Gardasil, the earlier quadrivalent HPV vaccine.

Moro PL, McNeil MM. Challenges in evaluating post-licensure vaccine safety: observations from the Center for Disease Control and Prevention.external icon Expert Rev Vaccines. 2019 Oct; 18(10): 1091-1101 Epub 2019 Oct 19.

There is overwhelming scientific evidence that supports the safety of vaccines and their proven ability to prevent illness and death caused by infectious diseases. Yet like any medicine, no vaccine can be considered completely safe and completely effective. Prior to licensure, vaccines undergo extensive safety and efficacy evaluations. After licensure, they require follow up studies and continuous monitoring to investigate any new or unexpected adverse events (AEs). This article presents challenges in monitoring U.S. vaccines for AEs after licensure and describes CDC’s post-licensure safety surveillance infrastructure, including the Vaccine Adverse Event Reporting System, the Vaccine Safety Datalink, and the Clinical Immunization Safety Assessment project. The authors describe each system’s unique strengths and limitations, and the harmonized approach they provide in meeting vaccine safety monitoring challenges.

McNeil MM, Paradowska-Stankiewicz I, Miller ER, Marquez PL, Seshadri S, Collins LC Jr, Cano MV. 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.external icon Vaccine. 2019 Oct 16; 37(44): 6760-6767 Epub 2019 Sep 20.

Adenovirus vaccine (adenovirus type 4 and type 7, live, oral) was licensed by FDA in March 2011 for use in U.S. military personnel ages 17-50 years. The vaccine was first routinely given to recruits in October 2011. Researchers reviewed reports of adverse events (AEs) following the adenovirus vaccine from October 2011 to July 2018 using the Vaccine Adverse Event Reporting System (VAERS). VAERS received 100 adverse event reports; 39 were considered serious. While the reporting rate for serious AEs was higher than with other vaccines given in a comparison recruit population (39% versus 18%), no unexpected or concerning pattern of adenovirus vaccine AEs were identified. Reports showed multiple other vaccines (95%) and penicillin G (50%) were given at the same time, and these exposures may have contributed to the higher reporting rate for serious AEs observed with the adenovirus vaccine. Future studies without these exposures would be helpful in clarifying the vaccine’s safety profile.

McNeil MM. Vaccine-Associated Anaphylaxisexternal icon. Curr Treat Options Allergy. 2019 Sep; 6(3): 297-308. Epub 2019 Jul 16

Anaphylaxis is a rare, serious hypersensitivity reaction, which can happen within minutes and is characterized by multisystem involvement. Although anaphylaxis may occur after any vaccine, the risk following flu vaccines is important to understand due to the large number of persons vaccinated annually. This review looks at two recent CDC studies that confirm its rarity. In a 25-year review of data from the Vaccine Adverse Event Reporting System, reports in children most commonly followed childhood vaccinations, and in adults most often followed influenza vaccine. In a Vaccine Safety Datalink study, the estimated incidence of anaphylaxis was 1.3 per million vaccine doses administered for all vaccines and 1.6 per million doses for IIV3 (trivalent) influenza vaccine. Despite its rarity, the rapid onset and potentially lethal nature of anaphylaxis requires that all personnel and facilities providing vaccinations have procedures in place to treat it.

Hesse EM, Hibbs BF, Cano MV. Notes from the Field: Administration of Expired Injectable Influenza Vaccines Reported to the Vaccine Adverse Event Reporting System — United States, July 2018–March 2019.external icon MMWR Morb Mortal Wkly Rep. 2019; 68: 529–530. 2019 June 14.

During the 2018-2019 flu season, the Vaccine Adverse Event Reporting System received 125 reports (totaling 192 patients) of people receiving expired inactivated influenza vaccine (IIV). During that time, 169.1 million doses of seasonal flu vaccine were distributed. Of those who received the expired IIV, 70% were in high-risks group for influenza (under the age of 5, over the age of 50 and pregnant women). Researchers found the reported adverse events were consistent with adverse events following administration of non-expired seasonal IIV, suggesting no additional safety issues associated with receipt of expired IIV. To avoid inadvertent administration of expired IIV, CDC recommends facilities that administer vaccines follow the guidance in the Vaccine Storage and Handling Toolkit, and make plans for the safe disposal or return of any remaining IIV after the expiration date of June 30 each year.

Moro PL, Arana J, Marquez PL, Ng C, Barash F, Hibbs BF, Cano M. Is there any harm in administering extra-doses of vaccine to a person? Excess doses of vaccine reported to the Vaccine Adverse Event Reporting System (VAERS), 2007-2017.external icon Vaccine. 2019 Jun 19; 37(28): 3730-3734. Epub 2019 May 30.

The administration of an extra dose of a vaccine may occur due to a vaccination error or when there is need to provide immunization in a person with uncertain vaccination histories (e.g., refugees). There is little data available on the safety of an extra dose of vaccine. Researchers searched for adverse events following the administration of excess doses of vaccines using the Vaccine Adverse Events Reporting System from January 2007 through the end of July 2017. Of 366,815 total reports received, over 5,000 (1.4%) reported an excess dose of vaccine was administered and less than 4,000 (76.9%) did not describe an AE. The top two vaccines reported were trivalent inactivated influenza (15.4%), and varicella (13.9%). The most common events were fever (12.8%), and injection site reaction (9.7%). Among reports where an AE was reported, researchers did not observe any unexpected conditions or clustering of AEs.

Kochhar S, Edwards KM, Ropero Alvarez AM, Moro PL, Ortiz JR. Introduction of new vaccines for immunization in pregnancy – Programmatic, regulatory, safety and ethical considerationsexternal icon. Vaccine. 2019 May 31; 37(25): 3267-3277. Epub 2019 May 6.

Women are encouraged to get immunizations when they are pregnant; but in certain areas of the world, there are no programs to implement vaccine recommendations. Maternal immunization is a promising strategy to reduce infectious disease-related illness and death in pregnant women and their infants. Pre-requisites for introducing immunization during pregnancy include: (1) political commitment and adequate financial resources, (2) healthcare workers to deliver vaccines, (3) combining immunization programs with prenatal care and maternal/child health services, and (4) access to prenatal care for pregnant women in low and middle-income countries where births occur in healthcare facilities. A system to advance a vaccine program from product licensure to successful country-level implementation needs to include evidence of anticipated vaccine program impact, developing supportive policies, and translating policies into local action.

Su JR, Moro PL, Ng CS, Lewis PW, Said MA, Cano MV. Anaphylaxis after vaccination reported to the Vaccine Adverse Event Reporting System, 1990-2016.external icon J Allergy Clin Immunol. 2019 Apr;143(4):1465-1473. Epub 2019 Jan 14.

Anaphylaxis is a rare, potentially life-threatening hypersensitivity reaction that can occur after vaccination. During 1990–2016, the Vaccine Adverse Event Reporting System (VAERS) received a total of 467,960 reports. Researchers identified 828 reports describing persons who were physician-diagnosed with or met the Brighton Collaboration case definition for anaphylaxis. Of reports in people aged 18 years or younger, 65% were male; childhood vaccines were most commonly reported. Of reports in people aged 19 years and older, 80% were female, and influenza vaccines were most commonly reported. Over 40% of the 828 reports described persons with no history of hypersensitivity. Of 8 reported deaths, 4 had no history of hypersensitivity. Anaphylaxis after vaccination is rare, but can occur, including among persons with no history of hypersensitivity. Providers who administer vaccines should be prepared to manage severe hypersensitivity reactions.

Haber P, Moro PL, Ng C, Dores GM, Lewis P, Cano M. Post-licensure surveillance of trivalent adjuvanted influenza vaccine (aIIV3; Fluad), Vaccine Adverse Event Reporting System (VAERS), United States, July 2016-June 2018.external icon Vaccine. 2019 Mar 7;37(11):1516-1520. Epub 2019 Feb 7.

Trivalent adjuvanted influenza vaccine (aIIV3; Fluad®) was approved in the U.S. in 2015 for adults aged 65 years and older, and has been in use since the 2016-2017 influenza season. Using the Vaccine Adverse Event Reporting System, researchers analyzed U.S. reports for aIIV3 submitted from July 2016 to June 2018, totaling 630 reports. Of note, there were 79 reports of people under the age of 65 who received the vaccine. The most commonly reported adverse events were consistent with pre-licensure studies, and included injection site pain and redness. Researchers did not identify any new safety concerns associated with aIIV3 among individuals indicated for the vaccine (65 years of age or older). Importantly, vaccine providers should be aware of and follow the prescribing information for the vaccine and administer it only to patients in the recommended age range.

Hesse EM, Shimabukuro TT, Su JR, et al. Postlicensure Safety Surveillance of Recombinant Zoster Vaccine (Shingrix) — United States, October 2017–June 2018. MMWR Morb Mortal Wkly Rep 2019;68:91–94.

This is the first report covering post-licensure safety monitoring of the recombinant zoster vaccine (RZV; Shingrix, GSK) in the Vaccine Adverse Event Reporting System (VAERS) during the initial 8 months of use in the United States. From October 2017 to June 2018, VAERS received 4,381 adverse event reports related to Shingrix; 4,251 (97%) were classified as non-serious. During that timeframe, about 3.2 million doses of Shingrix were distributed in the United States. The most common symptoms reported were fever, and injection site pain and redness. These findings are consistent with pre-licensure clinical trial data, and no unexpected patterns were detected. Clinicians should counsel patients to expect common reactions such as pain, swelling, and redness at the injection site, along with possible body aches, fever, and chills. These reactions usually resolve on their own in 2 to 3 days.

Landazabal CS, Moro PL, Lewis P, Omer SB. Safety of 9-valent human papillomavirus vaccine administration among pregnant women: Adverse event reports in the Vaccine Adverse Event Reporting System (VAERS), 2014-2017external icon. Vaccine. 2019 Feb 21;37(9):1229-1234. Epub 2019 Jan 16.

9-valent human papillomavirus vaccine (9vHPV) was approved by FDA in December 2014. 9vHPV is not recommended during pregnancy but some women of childbearing age may be inadvertently exposed. This study assessed reports to Vaccine Adverse Event Reporting System (VAERS) of pregnant women vaccinated with 9vHPV in the United States between December 2014-December 2017. Disproportionate reporting of adverse events (AEs) was assessed using proportional reporting ratios. A total of 82 pregnancy reports were identified. Sixty reports (73.2%) did not describe an AE. The most frequently reported AEs were miscarriage and injection site reactions (both n=3; 3.7%). Of note, miscarriage may occur in up to one-third of pregnancies; the observed reports in this study were not unusual or unexpected. No disproportional reporting for any AE was found. Overall, no unexpected AEs were observed among these pregnancy reports.