Systematic Review and Meta-analysis of Postlicensure Observational Studies on Human Papillomavirus Vaccination and Autoimmune and Other Rare Adverse Events

A feasibility assessment of real-world data capabilities for monitoring vaccine safety and effectiveness in China: Human papillomavirus vaccination in the Yinzhou district as a use case

BACKGROUND

Real-world data (RWD) are increasingly used to generate real-world evidence (RWE) of vaccine safety and effectiveness for regulatory purposes. Assessing feasibility of using RWD sources prior to implementing observational studies is recommended. As a use case, we described the process and findings of a feasibility assessment to identify reliable and relevant data sources for monitoring the safety and effectiveness of the AS04-HPV-16/18 human papillomavirus (HPV) vaccine in China.

METHODS

Iterative multi-step process: (1) targeted literature review and data source mapping; (2) expert opinion from national RWD experts; (3) survey to evaluate the identified data source operational infrastructure; and (4) continuous appraisal of published studies using the identified data source.

RESULTS

The Yinzhou Regional Health Information Platform (YRHIP) was identified as a data source of main interest, based on its large population coverage, high cervical cancer screening rates, and availability of adult electronic immunization records. Field meetings with national RWD experts confirmed its suitability for post-authorization vaccine studies. Survey results showed that exposure data and relevant safety and effectiveness endpoints were recorded and linkable at the individual level across the platform. Iterative appraisal of emerging evidence from the literature corroborated these findings.

CONCLUSIONS

This feasibility assessment indicates that the YRHIP has the capacity to capture demographic, exposure, outcome and other data required to generate RWE on HPV vaccine safety and effectiveness in China. Studies using the YRHIP to monitor the AS04-HPV-16/18 vaccine in routine use building on this feasibility assessment are ongoing.

Incident autoimmune conditions among males receiving quadrivalent human papillomavirus vaccine in the United States

BACKGROUND

The potential for vaccines to induce autoimmunity has been the subject of considerable investigation and autoimmune induction remains a common focus for vaccine safety research. This study assessed the risk of new onset autoimmune conditions among males receiving the 4-valent human papillomavirus (HPV) vaccine (4vHPV).

METHODS

Within a US health insurance claims database, we formed a cohort of male 4vHPV vaccine recipients between 2009 and 2016, along with a propensity score matched cohort of males who did not receive the 4vHPV vaccine. The study outcome was new onset autoimmune conditions (20 separate conditions) within four categories (rheumatologic/hematologic, gastroenterologic, endocrinologic and neurologic/ophthalmalogic). Outcomes identified using diagnosis codes were adjudicated through medical record review. Incidence rates (per 1,000 person-years) were estimated for the vaccinated and unvaccinated groups along with rate ratios (RRs).

RESULTS

There were 65,606 males receiving at least one dose of 4vHPV vaccine, and 55,670 were matched to a comparator. The matched 4vHPV vaccine cohort provided 35 confirmed cases among 39,735 person-years, for an incidence rate of 0.88 (95% CI: 0.61-1.23), while the comparator cohort provided 47 confirmed cases among 58,215 person-years, an incidence rate of 0.81 (0.59-1.07), a RR of 1.09 (0.70-1.69). The RR within categories was 0.49 (0.10-2.42) for rheumatologic/hematologic, 1.26 (0.58-2.71) for gastroenterologic, 1.11 (0.61-2.02) for endocrinologic and 1.46 (0.21-10.40) for neurologic.

CONCLUSIONS

The incidence of autoimmune conditions among males receiving the 4vHPV vaccine was similar to that among unvaccinated males. These results are consistent with other studies that have assessed autoimmunity with the 4vHPV vaccine.

Thyroid Inconveniences With Vaccination Against SARS-CoV-2: The Size of the Matter. A Systematic Review

After the beginning of COVID-19 vaccination campaigns, several reports of thyroid disease possibly related to the COVID-19 vaccination progressively appeared in the literature, raising the question of whether the thyroid disorder might be a SARS-CoV-2 vaccine complication. The aim of this study was to analyze the data about COVID-19 vaccination and thyroid disease, evaluate the size and quality of related literature, assess the type of these events, and investigate their timing of onset with respect the vaccination. Pubmed/MEDLINE and Cochrane were systematically reviewed until February 2022 to retrieve the largest number of original papers, case reports, and case series articles reporting thyroid disease after SARS-CoV-2 vaccination. Forty-six articles were included with a total of 99 patients aged from 26 to 73 years were described, of whom 74.75% female. Regarding the vaccination received, 49.49% of patients received Comirnaty (Pfizer/BioNTech), 14.14% CoronaVac (Sinovac), 12.12% Vaxzevria (Oxford/Astrazeneca), 11.11% Spikevax (Moderna), 3.03% Ad26.COV2.S (Janssen, Johnson & Johnson), one patient Covaxin (Bharat Biotech) and one patient Convidecia (Cansino). In 7 cases the thyroid disorder developed after the third dose with a combination of different vaccines. Regarding the type of thyroid disorder, 59 were subacute thyroiditis (SAT), 29 Graves' disease (GD), 2 co-occurrence of SAT and GD, 6 painless thyroiditis (PT), and single cases of thyroid eye disease and hypothyroidism associated with mixedema. The timeline between vaccination and thyroid disorder ranged between 0.5 to 60 days, with an average of 10.96 days. Considering the limited follow-up time, a complete remission was reported in most of SAT and PT cases while a persistence was observed in GD. In conclusion, both size and quality of published data about thyroid inconveniences after COVID-19 vaccination are limited; thyroid disorders may occur within 2 months after COVID-19 vaccination; among all thyroid diseases after COVID-19 vaccination, GD and SAT seem to be more frequent.

Vaccines

The safety of COVID-19 vaccines, as was the case last year, remains a large part of the focus in this volume. COVID-19 placed a large magnifying glass on both vaccines, specifically vaccine safety. This was most readily apparent as the number of records in VAERS ballooned to about 10 times the size from 2020 to 2021 (Vaccine Adverse Event Reporting System (VAERS), 2022) [S]. While we have added and/or improved VAERS during COVID-19, including adding or improving other vaccine safety surveillance tools like v-safe and vaccine safety datalink (Blumenthal, Phadke, et al., 2021) [MC], there is still room for improvement in these pharmacovigilance tools (Rizk et al., 2021) [r]. A major global initiative in this realm is the Global Vaccines Safety Blueprint 2.0 (GVSB2.0) (Organization, 2021, pp. 2021–2023) [S]. We wholeheartedly endorse these initiatives, which could significantly improve vaccine safety.

As noted in past SEDA issues, clinicians should be mindful of the risks of AEs and SAEs associated with each individual vaccine.

Raynaud's Phenomenon after COVID-19 Vaccination: Causative Association, Temporal Connection, or Mere Bystander?

Herein, we report a case of a new-onset Raynaud's phenomenon (RP), which occurred in an otherwise healthy 31-year-old Caucasian woman, who lacked any known risk factors and associations with possible causes for secondary RP. However, 2 weeks prior to the development of RP, the patient had received her first injection of the COVID-19 vaccine containing ChAdOx1-SARS-COV-2. The patient presented with well-demarcated, white-pale, cold areas involving the middle fingers of both hands and the ring finger of the right hand, which were triggered by exposure to cold environment and accompanied by a sensation of numbness. Infrared thermography revealed notable temperature differences of up to 10.9°C between affected and nonaffected fingers. Coagulation and immunological parameters, including cryoglobulins and pathological autoantibodies, were within the normal range and antibodies to the heparin/platelet factor 4 complex not detectable. It remains unclear if the development of RP in our patient is causally related to antecedent COVID-19 vaccination; however, the temporal connection to the vaccination, the complete absence of RP in her past medical history, and the lack of any risk factors and triggers raise the suspicion of a yet unknown association with the vaccine. Whether a clear association between the development of RP and COVID-19 vaccination exists or whether RP represents a bystander effect needs to be awaited in case observational reports on RP accumulate. Given the steadily rising numbers of people receiving COVID-19 vaccinations, physicians may remain alert to still unrecognized side effects.

Vaccinations and Autoimmune Diseases

Vaccines represent one of the most effective measures of public health medicine, saving countless lives and preventing lifelong disabilities. Vaccines are extremely safe, however, no vaccine is completely free from risks and adverse events can occur following vaccination. An adverse event following immunization (AEFI) may be a true adverse reaction caused by the vaccine or an event that temporally occurred after immunization but is not caused by it. Among the adverse reactions to vaccines, one of the most feared is the triggering of autoimmune diseases, which are a heterogeneous group of disorders characterized by dysregulation of the immune system. Currently, no mechanisms have been demonstrated that could explain the correlation between vaccination and the development of autoimmune diseases. Furthermore, epidemiological studies do not support the hypothesis that vaccines cause systemic autoimmune diseases. The only confirmed associations, although very rare, are those between the flu vaccine and Guillain-Barré syndrome, especially with old vaccine preparations, and measles-mumps-rubella (MMR) vaccine and thrombocytopenia. Due to the SARS-CoV2 pandemic, new types of vaccines have been developed and are now available. Close vaccine safety-surveillance is currently underway for these new vaccines.

Association between human papillomavirus vaccination and serious adverse events in South Korean adolescent girls: nationwide cohort study

OBJECTIVE

To evaluate the association between human papillomavirus (HPV) vaccination and serious adverse events in adolescent girls in South Korea.

DESIGN

Cohort study.

SETTING

A large linked database created by linking the Korea Immunization Registry Information System and the National Health Information Database, between January 2017 and December 2019.

PARTICIPANTS

441 399 girls aged 11-14 years who had been vaccinated in 2017: 382 020 had been vaccinated against HPV and 59 379 had not been vaccinated against HPV.

MAIN OUTCOME MEASURES

Outcomes were 33 serious adverse events, including endocrine, gastrointestinal, cardiovascular, musculoskeletal, haematological, dermatological, and neurological diseases. A cohort design was used for the primary analysis and a self-controlled risk interval design for the secondary analysis; both analyses used a risk period of one year after HPV vaccination for each outcome. Incidence rate and adjusted rate ratios were estimated using Poisson regression in the primary analysis, comparing the HPV vaccinated group with the HPV unvaccinated group, and adjusted relative risks were estimated using conditional logistic regression in the secondary analysis.

RESULTS

Among the 33 predefined serious adverse events, no associations were found with HPV vaccination in the cohort analysis, including Hashimoto's thyroiditis (incidence rate per 100 000 person years: 52.7 v 36.3 for the vaccinated and unvaccinated groups; adjusted rate ratio 1.24, 95% confidence interval 0.78 to 1.94) and rheumatoid arthritis (incidence rate per 100 000 person years: 168.1 v 145.4 for the vaccinated and unvaccinated groups; 0.99, 0.79 to 1.25), with the exception of an increased risk observed for migraine (incidence rate per 100 000 person years: 1235.0 v 920.9 for the vaccinated and unvaccinated groups; 1.11, 1.02 to 1.22). Secondary analysis using self-controlled risk intervals confirmed no associations between HPV vaccination and serious adverse events, including migraine (adjusted relative risk 0.67, 95% confidence interval 0.58 to 0.78). Results were robust to varying follow-up periods and for vaccine subtypes.

CONCLUSIONS

In this nationwide cohort study, with more than 500 000 doses of HPV vaccines, no evidence was found to support an association between HPV vaccination and serious adverse events using both cohort analysis and self-controlled risk interval analysis. Inconsistent findings for migraine should be interpreted with caution considering its pathophysiology and the population of interest.

Vaccines

In this volume of the Side Effects of Drugs Annual, although other vaccines will be covered, the safety of COVID vaccines is the focus as COVID-19 has led to heightened attention on vaccine safety in general. As such, this chapter will be more relevant than ever before. As noted in past SEDA issues, clinicians should be mindful of the risks of AEs and SAEs associated with each vaccine.

Do Vaccines Have a Role as a Cause of Autoimmune Neurological Syndromes?

Vaccines are the most important preventive measure against infectious diseases presently available. Although they have led to the eradication or the elimination of some infectious diseases, concerns about safety are among the main reasons for vaccine hesitancy. In some cases, the biological plausibility of a given damage in association with the temporal association between vaccine administration and disease development makes it difficult to define causality and can justify hesitancy. Only well-conducted epidemiological studies with adequate evaluation of results can clarify whether a true association between vaccines and adverse event development truly exists. Autoimmune neurological syndromes that follow vaccine use are among these. In this narrative review, the potential association between vaccines and the development of these syndromes are discussed. Literature analysis showed that most of the associations between vaccines and nervous system autoimmune syndromes that have been reported as severe adverse events following immunization are no longer evidenced when well-conducted epidemiological studies are carried out. Although the rarity of autoimmune diseases makes it difficult to strictly exclude that, albeit exceptionally, some vaccines may induce an autoimmune neurological disease, no definitive demonstration of a potential role of vaccines in causing autoimmune neurological syndromes is presently available. Consequently, the fear of neurological autoimmune disease cannot limit the use of the most important preventive measure presently available against infectious diseases.