Prevention of Hepatitis A Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2020.

HEPATITIS A IS A VACCINE-PREVENTABLE, COMMUNICABLE DISEASE OF THE LIVER CAUSED BY THE HEPATITIS A VIRUS (HAV). THE INFECTION IS TRANSMITTED VIA THE FECAL-ORAL ROUTE, USUALLY FROM DIRECT PERSON-TO-PERSON CONTACT OR CONSUMPTION OF CONTAMINATED FOOD OR WATER. HEPATITIS A IS AN ACUTE, SELF-LIMITED DISEASE THAT DOES NOT RESULT IN CHRONIC INFECTION. HAV ANTIBODIES (IMMUNOGLOBULIN G [IGG] ANTI-HAV) PRODUCED IN RESPONSE TO HAV INFECTION PERSIST FOR LIFE AND PROTECT AGAINST REINFECTION; IGG ANTI-HAV PRODUCED AFTER VACCINATION CONFER LONG-TERM IMMUNITY. THIS REPORT SUPPLANTS AND SUMMARIZES PREVIOUSLY PUBLISHED RECOMMENDATIONS FROM THE ADVISORY COMMITTEE ON IMMUNIZATION PRACTICES (ACIP) REGARDING THE PREVENTION OF HAV INFECTION IN THE UNITED STATES. ACIP RECOMMENDS ROUTINE VACCINATION OF CHILDREN AGED 12-23 MONTHS AND CATCH-UP VACCINATION FOR CHILDREN AND ADOLESCENTS AGED 2-18 YEARS WHO HAVE NOT PREVIOUSLY RECEIVED HEPATITIS A (HEPA) VACCINE AT ANY AGE. ACIP RECOMMENDS HEPA VACCINATION FOR ADULTS AT RISK FOR HAV INFECTION OR SEVERE DISEASE FROM HAV INFECTION AND FOR ADULTS REQUESTING PROTECTION AGAINST HAV WITHOUT ACKNOWLEDGMENT OF A RISK FACTOR. THESE RECOMMENDATIONS ALSO PROVIDE GUIDANCE FOR VACCINATION BEFORE TRAVEL, FOR POSTEXPOSURE PROPHYLAXIS, IN SETTINGS PROVIDING SERVICES TO ADULTS, AND DURING OUTBREAKS.

Prevention of Hepatitis B Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices.

HEPATITIS B VIRUS (HBV) IS TRANSMITTED VIA BLOOD OR SEXUAL CONTACT. PERSONS WITH CHRONIC HBV INFECTION ARE AT INCREASED RISK FOR CIRRHOSIS AND LIVER CANCER AND REQUIRE MEDICAL CARE. THIS REPORT UPDATES AND SUMMARIZES PREVIOUSLY PUBLISHED RECOMMENDATIONS FROM THE ADVISORY COMMITTEE ON IMMUNIZATION PRACTICES (ACIP) AND CDC REGARDING THE PREVENTION OF HBV INFECTION IN THE UNITED STATES. ACIP RECOMMENDS TESTING ALL PREGNANT WOMEN FOR HEPATITIS B SURFACE ANTIGEN (HBSAG), AND TESTING HBSAG-POSITIVE PREGNANT WOMEN FOR HEPATITIS B VIRUS DEOXYRIBONUCLEIC ACID (HBV DNA); ADMINISTRATION OF HEPB VACCINE AND HEPATITIS B IMMUNE GLOBULIN (HBIG) FOR INFANTS BORN TO HBV-INFECTED WOMEN WITHIN 12 HOURS OF BIRTH, FOLLOWED BY COMPLETION OF THE VACCINE SERIES AND POSTVACCINATION SEROLOGIC TESTING; UNIVERSAL HEPATITIS B VACCINATION WITHIN 24 HOURS OF BIRTH, FOLLOWED BY COMPLETION OF THE VACCINE SERIES; AND VACCINATION OF CHILDREN AND ADOLESCENTS AGED <19 YEARS WHO HAVE NOT BEEN VACCINATED PREVIOUSLY. ACIP RECOMMENDS VACCINATION OF ADULTS AT RISK FOR HBV INFECTION, INCLUDING UNIVERSAL VACCINATION OF ADULTS IN SETTINGS IN WHICH A HIGH PROPORTION HAVE RISK FACTORS FOR HBV INFECTION AND VACCINATION OF ADULTS REQUESTING PROTECTION FROM HBV WITHOUT ACKNOWLEDGMENT OF A SPECIFIC RISK FACTOR. THESE RECOMMENDATIONS ALSO PROVIDE CDC GUIDANCE FOR POSTEXPOSURE PROPHYLAXIS FOLLOWING OCCUPATIONAL AND OTHER EXPOSURES. THIS REPORT ALSO BRIEFLY SUMMARIZES PREVIOUSLY PUBLISHED AMERICAN ASSOCIATION FOR THE STUDY OF LIVER DISEASEST GUIDELINES FOR MATERNAL ANTIVIRAL THERAPY TO REDUCE PERINATAL HBV TRANSMISSION.

Notes from the field: reports of expired live attenuated influenza vaccine being administered--United States, 2007-2014.

Annual influenza vaccination is recommended for all persons aged ≥6 months. Two vaccine types are approved in the United States, injectable inactivated influenza vaccine (IIV) and live attenuated influenza vaccine (LAIV), which is administered intranasally. Influenza vaccine typicaly becomes widely available beginning in late summer or early fall. IIV has a standard expiration date of June 30 for any given influenza season (July 1 through June 30 of the following year). In contrast, after release for distribution, LAIV generally has an 18-week shelf life (Christopher Ambrose, MedImmune, personal communication, 2014). Because of its relatively short shelf life, LAIV might be more likely than IIV to be administered after its expiration date. To assess that hypothesis, CDC analyzed reports to the Vaccine Adverse Event Reporting System (VAERS) of expired LAIV administered during July 1, 2007, through June 30, 2014.

Postlicensure safety surveillance for high-dose trivalent inactivated influenza vaccine in the Vaccine Adverse Event Reporting System, 1 July 2010-31 December 2010.

BACKGROUND: In December 2009, a new high-dose, trivalent, inactivated influenza vaccine (TIV-HD) was licensed for adults aged ≥65 years. We characterized clinical patterns of reports to the Vaccine Adverse Event Reporting System (VAERS) among older adults who received TIV-HD. METHODS: We searched VAERS for reports involving persons aged ≥65 years who received TIV-HD or TIV (standard dose) from 1 July 2010 through 31 December 2010. Medical records were requested for serious reports (ie, those associated with death, hospitalization or prolonged hospitalization, life-threatening illness, or disability). Clinicians reviewed information and assigned a diagnostic category to each report. Empirical Bayesian data mining was used to identify disproportional reporting following TIV-HD in VAERS. Reporting rates were calculated for reports of Guillain-Barré syndrome and anaphylaxis. RESULTS: VAERS received 606 reports after TIV-HD in persons aged ≥65 years (8.2% of reports involved serious events). The number of reports yielded by searches using the terms "ocular hyperemia" and "vomiting" exceeded the data mining threshold; >80% of these reports were nonserious. Clinical review of serious reports found that a greater proportion involving gastrointestinal events were made after TIV-HD receipt (5 of 51 [9.8%]) than after TIV receipt (1 of 123 [0.8%]). Four persons who received TIV-HD had gastroenteritis, and 1 had multiple gastrointestinal symptoms; all recovered. A higher proportion of cardiac events were noted after receipt of TIV-HD (9 of 51 [17.6%]) than after receipt of TIV (6 of 123 [4.9%]). No concerning clinical pattern was apparent. The reporting rates of Guillain-Barré syndrome and anaphylaxis after TIV-HD receipt were 1.4 and 1.0 reports per million doses distributed, respectively. CONCLUSIONS: During the first year after US licensure of TIV-HD, no new serious safety concerns were identified in VAERS. Our analyses suggested a clinically important imbalance between the reported and expected number of gastrointestinal events after TIV-HD receipt. Future studies should assess this potential association.

Adverse event reports after tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccines in pregnant women.

OBJECTIVE: We sought to characterize reports to the Vaccine Adverse Event Reporting System (VAERS) of pregnant women who received tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap). STUDY DESIGN: We searched VAERS for reports of pregnant women who received Tdap from Jan. 1, 2005, through June 30, 2010. We conducted a clinical review of reports and available medical records. RESULTS: We identified 132 reports of Tdap administered to pregnant women; 55 (42%) described no adverse event (AE). No maternal or infant deaths were reported. The most frequent pregnancy-specific AE was spontaneous abortion in 22 (16.7%) reports. Injection site reactions were the most frequent non-pregnancy-specific AE found in 6 (4.5%) reports. One report with a major congenital anomaly (gastroschisis) was identified. CONCLUSION: During a time when Tdap was not routinely recommended in pregnancy, review of reports to VAERS in pregnant women after Tdap did not identify any concerning patterns in maternal, infant, or fetal outcomes.

Adverse events in pregnant women following administration of trivalent inactivated influenza vaccine and live attenuated influenza vaccine in the Vaccine Adverse Event Reporting System, 1990-2009.

OBJECTIVE: The objective of the study was to characterize reports to the Vaccine Adverse Event Reporting System (VAERS) in pregnant women who received seasonal influenza vaccines to assess for potential vaccine safety concerns. STUDY DESIGN: We searched VAERS for reports of adverse events (AEs) in pregnant women who received trivalent inactivated influenza vaccine (TIV) from July 1, 1990 through June 30, 2009, or live attenuated influenza vaccine (LAIV) from July 1, 2003, through June 30, 2009. RESULTS: A total of 148 reports after TIV and 27 reports after LAIV were identified. Twenty TIV (13.5%) and 1 LAIV (4%) reports were classified as serious. No specific AEs were reported in 30 TIV (20.3%) and 16 LAIV (59%) reports. The most common pregnancy-specific AE was spontaneous abortion: 17 after TIV (11.5%) and 3 after LAIV (11%). The reporting rate of spontaneous abortion was 1.9 per million pregnant women vaccinated. CONCLUSION: No unusual patterns of pregnancy complications or fetal outcomes were observed in the VAERS reports of pregnant women after the administration of TIV or LAIV.

Adverse events following administration to pregnant women of influenza A (H1N1) 2009 monovalent vaccine reported to the Vaccine Adverse Event Reporting System.

OBJECTIVE: The objective of the study was to evaluate and summarize reports to the Vaccine Adverse Event Reporting System (VAERS), a spontaneous reporting system, in pregnant women who received influenza A (H1N1) 2009 monovalent vaccine to assess for potential vaccine safety problems. STUDY DESIGN: We reviewed reports of adverse events (AEs) in pregnant women who received 2009-H1N1 vaccines from Oct. 1, 2009, through Feb. 28, 2010. RESULTS: VAERS received 294 reports of AEs in pregnant women who received 2009-H1N1 vaccine: 288 after inactivated and 6 after the live attenuated vaccines. Two maternal deaths were reported. Fifty-nine women (20.1%) were hospitalized. We verified 131 pregnancy-specific outcomes: 95 spontaneous abortions (<20 weeks); 18 stillbirths (≥20 weeks); 7 preterm deliveries (<37 weeks); 3 threatened abortions; 2 preterm labor; 2 preeclampsia; and 1 each of fetal hydronephrosis, fetal tachycardia, intrauterine growth retardation, and cleft lip. CONCLUSION: Review of reports to VAERS following H1N1 vaccination in pregnant women did not identify any concerning patterns of maternal or fetal outcomes.

Safety profile of rotavirus vaccines among individuals aged ≥8 months of age, United States, vaccine adverse event reporting system (VAERS), 2006-2019.

INTRODUCTION: In 2006 and 2008, two live, oral rotavirus vaccines, RotaTeq (RV5) and Rotarix (RV1), were introduced into the routine immunization program in the United States. A previous rotavirus vaccine, RotaShield, was associated with an increased risk of intussusception, with data suggesting an age-dependent variation in risk. Advisory Committee on Immunization Practices (ACIP) currently recommends that RV5 or RV1 immunization be initiated by age 14 weeks and 6 days and completed by 8 months 0 days. METHODS: We searched for U.S. VAERS reports of RV5, RV1, or unknown rotavirus vaccine brand among individuals aged ≥8 months. We analyzed reports by 2 age groups (individuals aged ≥8 months-≤5 years and ≥6 years), vaccine brand name, adverse event (AE) reported, classification of seriousness (death, non-death serious, and non-serious) and mode of exposure (direct vs. indirect exposure). For serious reports we reviewed available medical records and assigned a primary diagnosis. RESULTS: VAERS received a total of 344 U.S. reports following rotavirus vaccination among individuals ≥8 months of age, 32 (9.3%) were serious. In the younger age-group, 307 (99%) of 309 reports followed direct vaccination of the child. In contrast, in individuals aged ≥6 years, 21 (60%) of 35 reports were via potential indirect exposure to a vaccinated child. The frequently reported AEs in the younger age-group were inappropriate schedule of drug administration 104 (34%) and drug administered to patient of inappropriate age 45 (15%); in the older group these were accidental exposure 9 (26%) and eye irritation 7 (20%). No difference in the safety profile was observed between RV1 and RV5. CONCLUSIONS: We did not identify any unexpected AEs for RV vaccines among individuals aged ≥8 months. Health care providers should adhere to the ACIP recommended schedule and older individuals should apply necessary precautions to prevent potential secondary exposure from vaccinated children.

Erythema multiforme, Stevens Johnson syndrome, and toxic epidermal necrolysis reported after vaccination, 1999-2017.

BACKGROUND: Since the last review of vaccine safety surveillance data for erythema multiforme (EM), Stevens Johnson syndrome (SJS), SJS/TEN, and toxic epidermal necrolysis (TEN) (EM/SJS/TEN), over 37 new vaccines have been introduced in the United States. We sought to describe reported EM/SJS/TEN after vaccines during 1999-2017. METHODS: We identified U.S. reports of EM/SJS/TEN received by the Vaccine Adverse Event Reporting System (VAERS) during 1999-2017. We stratified analysis by condition (EM, SJS, or TEN), and analyzed reports by serious or non-serious status, sex, age group, time from vaccination to symptom onset, exposure to known causes of EM/SJS/TEN, and vaccines administered. We used Empirical Bayesian data mining to detect vaccine-AE pairs reported more frequently than expected. RESULTS: Of 466,027 reports to VAERS during 1999-2017, we identified 984 reports of EM, 89 reports of SJS, 6 reports of SJS/TEN, and 7 reports of TEN. Few reports of EM (9%), and most reports of SJS (52%), SJS/TEN (100%), and TEN (100%) were serious. Overall, 55% of reports described males, 48% described children aged < 4 years; 58% of EM/SJS/TEN occurred ≤ 7 days after vaccination. Few reports (≤5%) described exposure to known causes of EM/SJS/TEN. Overall, childhood vaccines (e.g., combined measles, mumps, and rubella vaccine) were most commonly reported. We identified 6 deaths; 4 were exposed to medications associated with EM/SJS/TEN. EM after smallpox vaccine was reported disproportionately among people aged 19-49 years. CONCLUSIONS: EM/SJS/TEN were rarely reported after vaccination; data mining identified a known association between EM and smallpox vaccine.

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.

INTRODUCTION: The Advisory Committee on Immunization Practices (ACIP) recommends vaccination with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) in persons ≥65 years of age. To date, few studies have assessed the safety of Tdap in this population. We aimed to summarize reports submitted to the Vaccine Adverse Event Reporting System (VAERS) following receipt of Tdap in this age group. METHODS: We searched for and analyzed U.S. VAERS reports of Tdap among individuals ≥65 years of age submitted from September 1, 2010 through December 31, 2018. We classified reports according to concurrent vaccination, seriousness, and outcome (death, non-death) and determined the frequency of reported adverse events (AEs). For serious reports, we reviewed available medical records. Data mining analyses were undertaken to detect disproportionality in reporting. RESULTS: VAERS received a total of 1,798 reports following Tdap, of which 104 (6%) were serious. The most common AEs were injection site erythema (26%; n = 468), injection site pain (19%; n = 335), injection site swelling (18%; n = 329), and erythema (18%; n = 321). We identified seven deaths; none were attributed to Tdap. Among serious non-death reports, nervous system disorders (35.1%; n = 34) and infections and infestations (n = 18.6%; n = 18) were most commonly reported. Data mining did not identify any vaccine-AE combination reported more frequently than expected. CONCLUSIONS: We did not identify any new safety concern over nearly a decade of recommended Tdap use among adults ≥65 years of age. Findings from this post-marketing review are consistent with prior post-marketing observations and pre-licensure studies.

Vaccines and Guillain-Barré syndrome.

Guillain-Barré syndrome (GBS) is the leading cause of acute flaccid paralysis in developed countries and is characterized by various degrees of weakness, sensory abnormalities and autonomic dysfunction. Although the underlying aetiology and pathophysiology of GBS are not completely understood, it is broadly believed that immune stimulation plays a role in its pathogenesis. Thus, since vaccines have an effect on the immune system it is biologically plausible that immunizations may be associated with subsequent GBS. The objective of this article is to review the current body of evidence that either supports or does not support a causal, rather than just temporal, association between various vaccines and GBS, and to provide an evidence-based review of this issue. The scope of the article includes published reports that, regardless of method of case ascertainment, appeared in peer-reviewed literature between 1950 and 2008. Our review indicates that, with rare exceptions, associations between vaccines and GBS have been only temporal. There is little evidence to support a causal association with most vaccines. The evidence for a causal association is strongest for the swine influenza vaccine that was used in 1976-77. Studies of influenza vaccines used in subsequent years, however, have found small or no increased risk of GBS. Older formulations of rabies vaccine cultured in mammalian brain tissues have been found to have an increased risk of GBS, but newer formulations of rabies vaccine, derived from chick embryo cells, do not appear to be associated with GBS at a greater than expected rate. In an earlier review, the Institute of Medicine concluded that the evidence favoured a causal association between oral polio vaccine and tetanus toxoid-containing vaccines and GBS. However, recent evidence from large epidemiological studies and mass immunization campaigns in different countries found no correlation between oral polio vaccine or tetanus toxoid-containing vaccines and GBS. Spontaneous reports to the US Vaccine Adverse Events Reporting System shortly after the introduction of quadrivalent conjugated meningococcal vaccine (MCV4) raised concerns of a possible association with GBS. Comparisons with expected rates of GBS, however, were inconclusive for an increased risk, and lack of controlled epidemiological studies makes it difficult to draw conclusions about a causal association. For other vaccines, available data are based on isolated case reports or very small clusters temporally related to immunizations, and no conclusion about causality can be drawn. There are certain circumstances in which immunizing individuals, particularly those with a prior history of GBS, may require caution. However, the benefit of vaccines in preventing disease and decreasing morbidity and mortality, particularly for influenza, needs to be weighed against the potential risk of GBS.

Death and serious illness following influenza vaccination: a multidisciplinary investigation.

PURPOSE: To evaluate a possible association between influenza vaccination and four deaths and four serious illnesses among 114 recent influenza vaccinees in a long-term care facility (LTCF) and two deaths from a nearby physician's office. All had received vaccine from the same lot (Lot A). METHODS: Field investigation including (1) a retrospective cohort study among LTCF residents who received Lot A or other influenza vaccine, (2) review of medical records of cases of death or serious illness, (3) active surveillance of deaths among 1500 community based Lot A vaccinees and (4) laboratory testing of vaccine from available Lot A vials. RESULTS: Medical record reviews showed no common clinical syndrome or cause of death. Laboratory testing of Lot A samples revealed no evidence of tampering and no differences compared to an unrelated lot. The risk of death or hospitalization was not significantly different between persons who received Lot A versus a comparison lot, Lot B (incidence rate ratio (IRR) = 0.9, 95%CI = 0.3-3.3). CONCLUSIONS: There was no clinical or biological evidence pointing to inherent vaccine safety issues, nor was there a detectable increased risk of death or hospitalization among persons vaccinated with Lot A. Lot specific clustering of adverse events (AEs) may reflect medical events causally unrelated to vaccination. Rapid investigations of potential AEs are important to ensure vaccine safety and to maintain public and healthcare provider confidence in vaccines.

Challenges in evaluating post-licensure vaccine safety: observations from the Centers for Disease Control and Prevention.

Introduction: Vaccination is one of the most successful and cost-effective public health interventions. Although vaccines undergo extensive safety and efficacy evaluations prior to licensure, vaccine safety assessment post-licensure is essential for detecting rare and longer-term adverse events (AEs) and maintaining public confidence in vaccines and recommended immunization programs. Despite the proven effect of vaccines to save lives and prevent disease and overwhelming evidence of vaccines' safety and societal benefit, like any drug, no vaccine can be considered as completely safe and completely effective. New vaccines continue to be introduced and require rapid safety assessment post-licensure through pharmacovigilance reports as well as epidemiologic studies to investigate any potential safety signals.Areas covered: We discuss selected challenges for conducting pharmacovigilance and epidemiologic studies of AEs after vaccination in the United States using the post-licensure safety surveillance infrastructure of the Centers for Disease Control and Prevention (CDC).Expert opinion: The availability of specific post-licensure surveillance systems to monitor and study AEs after vaccination, such as the Vaccine Adverse Event Reporting System, the Vaccine Safety Datalink, and the Clinical Immunization Safety Assessment Project, each with its unique set of strengths and limitations, provide a harmonized and supportive approach to meet several of these barriers.

Post-licensure surveillance of trivalent adjuvanted influenza vaccine (aIIV3; Fluad), Vaccine Adverse Event Reporting System (VAERS), United States, July 2016-June 2018.

BACKGROUND: Trivalent adjuvanted influenza vaccine (aIIV3; Fluad®) was approved in the United States (U.S.) in 2015 for adults aged ≥65 years and has been in use since the 2016-17 influenza season. METHODS: We analyzed U.S. reports for aIIV3 submitted from July 1, 2016 through June 30, 2018 to the Vaccine Adverse Event Reporting System (VAERS), a national spontaneous reporting system. Medical records were reviewed for serious reports. Among individuals ≥65 years of age, the relative frequency of the most commonly reported adverse events (AEs) after aIIV3 were compared with non-adjuvanted inactivated influenza vaccines given to adults aged ≥65 years, high-dose trivalent influenza vaccine (IIV3-HD) and trivalent or quadrivalent vaccines (IIV3/IIV4). Data mining analyses were undertaken to identify whether AEs for aIIV3 occurred disproportionately more than expected compared to all influenza vaccines. RESULTS: VAERS received 630 reports after aIIV3, of which 521 (83%) were in adults aged ≥65 years; 79 (13%) in persons <65 years and in 30 (5%) reports age was missing; 19 (3%) reports were serious, including two deaths (0.4%) related to myocardial infarction and Sjogren's syndrome. The most common AEs reported in adults aged ≥65 years were injection site pain (21%) and erythema (18%), with similar proportions reported for IIV3-HD (17% and 19%, respectively) and for IIV3/IIV4 (15%, each). Except for reports related to vaccination of inappropriate age (n = 79) and syringe malfunction (n = 6), data mining did not identify other disproportionately reported AEs. CONCLUSIONS: Although our review of aIIV3 in VAERS did not identify any unexpected health conditions of concern, we observed more than twice the expected number of reports with administration of the vaccine to persons outside of the age range for which the vaccine is approved in the U.S. Health care providers should be educated on the age groups for whom aIIV3 is recommended.

Prevention and control of influenza. Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2007.

This report updates the 2006 recommendations by CDC's Advisory Committee on Immunization Practices (ACIP) regarding the use of influenza vaccine and antiviral agents (CDC. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2006;55[No. RR-10]). The groups of persons for whom vaccination is recommended and the antiviral medications recommended for chemoprophylaxis or treatment (oseltamivir or zanamivir) have not changed. Estimated vaccination coverage remains <50% among certain groups for whom routine annual vaccination is recommended, including young children and adults with risk factors for influenza complications, health-care personnel (HCP), and pregnant women. Strategies to improve vaccination coverage, including use of reminder/recall systems and standing orders programs, should be implemented or expanded. The 2007 recommendations include new and updated information. Principal updates and changes include 1) reemphasizing the importance of administering 2 doses of vaccine to all children aged 6 months--8 years if they have not been vaccinated previously at any time with either live, attenuated influenza vaccine (doses separated by > or =6 weeks) or trivalent inactivated influenza vaccine (doses separated by > or =4 weeks), with single annual doses in subsequent years; 2) recommending that children aged 6 months--8 years who received only 1 dose in their first year of vaccination receive 2 doses the following year, with single annual doses in subsequent years; 3) highlighting a previous recommendation that all persons, including school-aged children, who want to reduce the risk of becoming ill with influenza or of transmitting influenza to others should be vaccinated; 4) emphasizing that immunization providers should offer influenza vaccine and schedule immunization clinics throughout the influenza season; 5) recommending that health-care facilities consider the level of vaccination coverage among HCP to be one measure of a patient safety quality program and implement policies to encourage HCP vaccination (e.g., obtaining signed statements from HCP who decline influenza vaccination); and 6) using the 2007--2008 trivalent vaccine virus strains A/Solomon Islands/3/2006 (H1N1)-like (new for this season), A/Wisconsin/67/2005 (H3N2)-like, and B/Malaysia/2506/2004-like antigens. This report and other information are available at CDC's influenza website (http://www.cdc.gov/flu). Updates or supplements to these recommendations (e.g., expanded age or risk group indications for currently licensed vaccines) might be required. Immunization providers should be alert to announcements of recommendation updates and should check the CDC influenza website periodically for additional information.

Reports of lower respiratory tract infection following dose 1 of RotaTeq and Rotarix vaccines to the Vaccine Adverse Event Reporting System (VAERS), 2008-2016.

A 2018 manufacturer post-licensure safety study identified a possible association between Rotarix (RV1) rotavirus vaccine and lower respiratory tract infections (LRTI) in infants within 0-6 days following receipt of RV1 dose 1. We reviewed reports to the Vaccine Adverse Event Reporting System (VAERS) of LRTI occurring 0-6 days and 0-29 days post vaccination following RotaTeq (RV5) or Rotarix (RV1) vaccinations in conjunction with either Prevnar (PCV7) or Prevnar 13 (PCV13), in infants aged 6 to 15 weeks. There was no significant difference in LRTI reports to VAERS in the 0-6 days and 0-29 days following receipt of either RV5 or RV1 given with either pneumococcal vaccine.

Safety of currently licensed hepatitis B surface antigen vaccines in the United States, Vaccine Adverse Event Reporting System (VAERS), 2005-2015.

INTRODUCTION: Currently four recombinant hepatitis B (HepB) vaccines are in use in the United States. HepB vaccines are recommended for infants, children and adults. We assessed adverse events (AEs) following HepB vaccines reported to the Vaccine Adverse Event Reporting System (VAERS), a national spontaneous reporting system. METHODS: We searched VAERS for reports of AEs following single antigen HepB vaccine and HepB-containing vaccines (either given alone or with other vaccines), from January 2005 - December 2015. We conducted descriptive analyses and performed empirical Bayesian data mining to assess disproportionate reporting. We reviewed serious reports including reports of special interest. RESULTS: VAERS received 20,231 reports following HepB or HepB-containing vaccines: 10,291 (51%) in persons <2 years of age; 2588 (13%) in persons 2-18 years and 5867 (29%) in persons >18 years; for 1485 (7.3%) age was missing. Dizziness and nausea (8.4% each) were the most frequently reported AEs following a single antigen HepB vaccine: fever (23%) and injection site erythema (11%) were most frequent following Hep-containing vaccines. Of the 4444 (22%) reports after single antigen HepB vaccine, 303 (6.8%) were serious, including 45 deaths. Most commonly reported cause of death was Sudden Infant Death Syndrome (197). Most common non-death serious reports following single antigen HepB vaccines among infants aged <1 month, were nervous system disorders (15) among children aged 1-23 months; infections and infestation (8) among persons age 2-18 years blood and lymphatic systemic disorders; and general disorders and administration site conditions among persons age >18 years. Most common vaccination error following single antigen HepB was incorrect product storage. CONCLUSIONS: Review current U.S.-licensed HepB vaccines administered alone or in combination with other vaccines did not reveal new or unexpected safety concerns. Vaccination errors were identified which indicate the need for training and education of providers on HepB vaccine indications and recommendations.

Safety of Second-Dose Single-Antigen Varicella Vaccine.

BACKGROUND AND OBJECTIVE: In 2006, routine 2-dose varicella vaccination for children was recommended to improve control of varicella. We assessed the safety of second-dose varicella vaccination. METHODS: We identified second-dose single-antigen varicella vaccine reports in the Vaccine Adverse Event Reporting System during 2006 to 2014 among children aged 4 to 18 years. We analyzed reports by age group (4-6 and 7-18 years), sex, serious or nonserious status, most common adverse events (AEs), and whether other vaccines were administered concomitantly with varicella vaccine. We reviewed serious reports of selected AEs and conducted empirical Bayesian data mining to detect disproportional reporting of AEs. RESULTS: We identified 14 641 Vaccine Adverse Event Reporting System reports after second-dose varicella vaccination, with 494 (3%) classified as serious. Among nonserious reports, injection site reactions were most common (48% of children aged 4-6 years, 38% of children aged 7-18 years). The most common AEs among serious reports were pyrexia (31%) for children aged 4 to 6 years and headache (28%) and vomiting (27%) for children aged 7 to 18 years. Serious reports of selected AEs included anaphylaxis (83), meningitis (5), encephalitis (16), cellulitis (52), varicella (6), herpes zoster (6), and deaths (7). One immunosuppressed adolescent was reported with vaccine-strain herpes zoster. Only previously known AEs were reported more frequently after second-dose varicella vaccination compared with other vaccines. CONCLUSIONS: We identified no new or unexpected safety concerns for second-dose varicella vaccination. Robust safety monitoring remains an important component of the national varicella vaccination program.

Surveillance systems and methods for monitoring the post-marketing safety of influenza vaccines at the Centers for Disease Control and Prevention.

INTRODUCTION: Annual influenza vaccine safety monitoring is an important component of the influenza vaccination program in the United States to ensure that vaccines are safe, which is important for maintaining public trust in the national vaccination program. This is specially the case for influenza vaccines since the antigen composition of the viruses of which the vaccine is made often changes from one season to the next, based on the circulating strain of influenza virus. AREAS COVERED: This review describes the two surveillance systems used by the Centers for Disease Control and Prevention (CDC) to monitor the safety of influenza vaccines: 1) the Vaccine Adverse Event Reporting System (VAERS); and 2) the Vaccine Safety datalink (VSD). EXPERT OPINION: VAERS and VSD are used routinely to monitor the safety of influenza vaccines in the United States, and over the years they have demonstrated their value in monitoring vaccine safety since their implementation in 1990. Both systems, although different, complemented each other well to study febrile seizures in young children following influenza vaccination during the 2010-2011 influenza season. Other examples of potential safety concerns after influenza vaccines are also presented and discussed.

Post-licensure surveillance of 13-valent pneumococcal conjugate vaccine (PCV13) in adults aged ⩾19years old in the United States, Vaccine Adverse Event Reporting System (VAERS), June 1, 2012-December 31, 2015.

BACKGROUND: The 13-valent pneumococcal conjugate vaccine (PCV13) was first recommended for use in adults aged ⩾19years with immunocompromising conditions in June 2012. On August 2014, the Advisory Committee on Immunization Practices (ACIP) recommended routine use of PCV13 among adults aged ⩾65years. METHODS: We assessed adverse events (AEs) reports following PCV13 in adults aged ⩾19years reported to the Vaccine Adverse Event Reporting System (VAERS) from June 2012 to December 2015. VAERS is a national spontaneous reporting system for monitoring AEs following vaccination. Our assessment included automated data analysis, clinical review of all serious reports and reports of special interest. We conducted empirical Bayesian data mining to assess for disproportionate reporting. RESULTS: VAERS received 2976 US PCV13 adult reports; 2103 (71%) of these reports were from PCV13 administered alone. Fourteen percent were in persons aged 19-64years and 86% were in persons aged ⩾65years. Injection site erythema (28%), injection site pain (24%) and fever (22%) were the most frequent AEs among persons aged 19-64years; injection site erythema (30%), erythema (20%) and injection site swelling (18%) were the most frequent among persons aged ⩾65years who were given the vaccine alone. The most frequently reported AEs among non-death serious reports were injection site reactions and general malaise among persons 19-64years old; injection site reactions, general malaise and Guillain-Barré syndrome among those ⩾65years (Table 2). Data mining did not detect disproportional reporting for any unexpected AE. CONCLUSIONS: The results of this study were consistent with safety data from pre-licensure studies of PCV13. We did not detect any new or unexpected AEs.