Vaccination and 30-Day Mortality Risk in Children, Adolescents, and Young Adults

A safety study evaluating non-COVID-19 mortality risk following COVID-19 vaccination

BACKGROUND

The safety of COVID-19 vaccines plays an important role in addressing vaccine hesitancy. We conducted a large cohort study to evaluate the risk of non-COVID-19 mortality after COVID-19 vaccination while adjusting for confounders including individual-level demographics, clinical risk factors, health care utilization, and community-level socioeconomic risk factors.

METHODS

The retrospective cohort study consisted of members from seven Vaccine Safety Datalink sites from December 14, 2020 through August 31, 2021. We conducted three separate analyses for each of the three COVID-19 vaccines used in the US. Crude non-COVID-19 mortality rates were reported by vaccine type, age, sex, and race/ethnicity. The counting process model for survival analyses was used to analyze non-COVID-19 mortality where a new observation period began when the vaccination status changed upon receipt of the first dose and the second dose. We used calendar time as the basic time scale in survival analyses to implicitly adjust for season and other temporal trend factors. A propensity score approach was used to adjust for the potential imbalance in confounders between the vaccinated and comparison groups.

RESULTS

For each vaccine type and across age, sex, and race/ethnicity groups, crude non-COVID-19 mortality rates among COVID-19 vaccinees were lower than those among comparators. After adjusting for confounders with the propensity score approach, the adjusted hazard ratios (aHRs) were 0.46 (95% confidence interval [CI], 0.44-0.49) after dose 1 and 0.48 (95% CI, 0.46-0.50) after dose 2 of the BNT162b2 vaccine, 0.41 (95% CI, 0.39-0.44) after dose 1 and 0.38 (95% CI, 0.37-0.40) after dose 2 of the mRNA-1273 vaccine, and 0.55 (95% CI, 0.51-0.59) after receipt of Ad26.COV2.S.

CONCLUSION

While residual confounding bias remained after adjusting for several individual-level and community-level risk factors, no increased risk was found for non-COVID-19 mortality among recipients of three COVID-19 vaccines used in the US.

Vaccination against Paediatric Respiratory Pathogens

Acute respiratory infections (ARIs) are extremely common in children, especially those under 5 years old. They can lead to complications, super-infection, respiratory failure, and even compromised respiratory function in adulthood. For some of the responsible pathogens, vaccines are available. This review reports current issues about vaccines against the main respiratory pathogens to highlight the available strategies to reduce the burden of paediatric respiratory disease. The optimal use of influenza, pneumococcal, pertussis and measles vaccines is required in order to reduce ARI burden. Vaccination coverage rates must be improved to achieve the full benefits of these vaccines. Recently, advances in the knowledge of respiratory syncytial virus structural biology and immunology as well as the development of new techniques to generate vaccine candidates have increased the number of promising vaccines even against this harmful pathogen.

Addressing HPV vaccine myths: practical information for healthcare providers

Human papillomavirus (HPV) vaccine uptake consistently lags behind that of other adolescent vaccines. In 2017, uptake of a single HPV vaccine dose and HPV vaccine series completion was 66% and 49%, respectively, compared to uptake of tetanus, diphtheria, and acellular pertussis vaccine (89%) and quadrivalent meningococcal conjugate vaccine (85%). Reasons for not vaccinating adolescents again HPV are varied, and in many cases, are rooted in commonly spread myths and misperceptions about the vaccine. In this review, we address five key myths - HPV vaccination is not effective at preventing cancer; Pap smears are sufficient to prevent cervical cancer; HPV vaccination is not safe; HPV vaccination is not needed since most infections are naturally cleared by the immune system; 11-12 years of age is too young to vaccinate. For each myth, we summarize the scientific evidence refuting the myth and provide speaking prompts for healthcare professionals to communicate about HPV vaccination.

Safety of Human Papillomavirus Vaccines: An Updated Review

Human papillomavirus (HPV) vaccines are now included in immunisation programmes in 71 countries. Unfortunately, uptake has been impacted in some countries by reduced confidence in the safety of the HPV vaccine. In 2013, we published an extensive review demonstrating a reassuring safety profile for bivalent (2vHPV) and quadrivalent (4vHPV) vaccines. A nonavalent (9vHPV) vaccine is now available and HPV immunisation programmes have been extended to males in 11 countries. The aim of this updated narrative review was to examine the evidence on HPV vaccine safety, focusing on the 9vHPV vaccine, special populations and adverse events of special interest (AESI). The previous searches were replicated to identify studies to August 2016, including additional search terms for AESI. We identified 109 studies, including 15 population-based studies in over 2.5 million vaccinated individuals across six countries. All vaccines demonstrated an acceptable safety profile; injection-site reactions were slightly more common for 9vHPV vaccine than for 4vHPV vaccine. There was no consistent evidence of an increased risk of any AESI, including demyelinating syndromes or neurological conditions such as complex regional pain or postural orthostatic tachycardia syndromes. The risk-benefit profile for HPV vaccines remains highly favourable.

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.

Post-licensure safety monitoring of quadrivalent human papillomavirus vaccine in the Vaccine Adverse Event Reporting System (VAERS), 2009-2015

BACKGROUND

The Food and Drug Administration (FDA) approved quadrivalent human papillomavirus vaccine (4vHPV) for use in females and males aged 9-26 years, since 2006 and 2009 respectively. We characterized reports to the Vaccine Adverse Event Reporting System (VAERS), a US spontaneous reporting system, in females and males who received 4vHPV vaccination.

METHODS

We searched VAERS for US reports of adverse events (AEs) following 4vHPV from January 2009 through December 2015. Signs and symptoms were coded using Medical Dictionary for Regulatory Activities (MedDRA). We calculated reporting rates and conducted empirical Bayesian data mining to identify disproportional reports. Clinicians reviewed available information, including medical records, and reports of selected pre-specified conditions.

FINDINGS

VAERS received 19,760 reports following 4vHPV; 60.2% in females, 17.2% in males, and in 22.6% sex was missing. Overall, 94.2% of reports were non-serious; dizziness, syncope and injection site reactions were commonly reported in both males and females. Headache, fatigue and nausea were commonly reported serious AEs. More than 60 million 4vHPV doses were distributed during the study period. Crude AE reporting rates were 327 reports per million 4vHPV doses distributed for all reports, and 19 per million for serious reports. Among 29 verified reports of death, there was no pattern of clustering of deaths by diagnosis, co-morbidities, age, or interval from vaccination to death.

INTERPRETATION

No new or unexpected safety concerns or reporting patterns of 4vHPV with clinically important AEs were detected. Safety profile of 4vHPV is consistent with data from pre-licensure trials and postmarketing safety data.

Patterns of childhood immunization and all-cause mortality

BACKGROUND

Evidence supports the safety of the recommended childhood immunization schedule as a whole. However, additional research is warranted as parents' refusing or delaying vaccinations has increased in recent years. All-cause mortality has been identified as a priority outcome to study in the context of the recommended immunization schedule.

METHODS

We included children born January 1, 2004 through December 31, 2009, enrolled in the Vaccine Safety Datalink (VSD) from birth through 18 months of age. We examined vaccination patterns during the first 18 months of life among 8 vaccines, and identified deaths occurring between 19 and 48 months of age. We excluded children with complex chronic conditions, contraindications to vaccination, and deaths due to injuries, congenital anomalies, or diseases with onset prior to 19 months of age. We calculated mortality rates among children with different patterns of immunization, and incidence rate ratios (IRR) using the Cox proportional hazards model for children vaccinated according to the schedule versus undervaccinated children, adjusting for outpatient healthcare utilization, influenza vaccination, sex, and VSD site.

RESULTS

Among 312,388 children in the study, 199,661 (64%) were vaccinated according to the schedule, and 112,727 (36%) were delayed or not vaccinated for at least one vaccine dose. Of 18 deaths eligible for analysis, 11 occurred in children following the schedule (2.28 per 100,000 person-years), and seven occurred in undervaccinated children (2.57 per 100,000 person-years). Mortality rates among children following the schedule were not significantly different from those of undervaccinated children when excluding deaths with unknown causes (IRR = 1.29, 95% CI = 0.33-4.99), as well as when including deaths with unknown causes (IRR = 0.84, 95% CI = 0.32-2.99).

CONCLUSION

Although there were few deaths, our results do not indicate a difference in risk of all-cause mortality among fully vaccinated versus undervaccinated children. Our findings support the safety of the currently recommended immunization schedule with regard to all-cause mortality.

Quadrivalent HPV vaccine safety review and safety monitoring plans for nine-valent HPV vaccine in the United States

Quadrivalent human papillomavirus (4vHPV) vaccine was licensed for use in the United States in 2006 and through 2015 was the predominate HPV vaccine used. With the exception of syncope, a known preventable adverse event after any injected vaccination, both pre-licensure and post-licensure 4vHPV safety data have been reassuring with no confirmed safety signals identified. Nine-valent HPV vaccine (9vHPV) was licensed in 2014. This review includes post-licensure 4vHPV safety findings published to date that have informed the US vaccination program; these data will inform US safety monitoring and evaluation for 9vHPV.