Quadrivalent human papillomavirus vaccination in boys and risk of autoimmune diseases, neurological diseases and venous thromboembolism

Identification of subgroups in the Danish population for targeted human papillomavirus vaccination efforts

BACKGROUND

In the Danish childhood vaccination program, the human papillomavirus (HPV) vaccination coverage is lower than for other vaccines. To tailor a targeted HPV vaccination effort, we aimed to identify girls in Denmark with lower first dose HPV vaccination coverage than girls in general.

METHODS

A population-based retrospective cohort study was performed of girls born in 2001-2004, residing in Denmark in September 2019 (N = 128,351). Data from the Danish Vaccination Register was linked to sociodemographic data from the Danish Civil Registration System and Statistics Denmark. Cox's proportional hazard regression models were used to compare vaccination uptake rates between subgroups of girls.

RESULTS

HPV vaccination coverage at 14 years of age varied widely by municipality (53.4-80.6%). Girls living with neither of their parents had a lower chance of being vaccinated compared to girls living with both their parents (HR 0.43; 95% CI 0.41-0.46), likewise for girls attending special need education compared with girls attending public schools (HR 0.50; 95% CI 0.42-0.59). The vaccination uptake among immigrants was lower compared to Danish-born girls (HR 0.51; 95% CI 0.49-0.54), especially among immigrant girls whose parents had not passed any Danish exams. Finally, girls who were DTaP-IPV revaccinated had a 50% greater chance of being HPV vaccinated compared to girls who were not (HR 1.61; 95% CI 1.58-1.64).

CONCLUSION

To increase the HPV vaccination uptake, we recommend vaccination efforts targeting girls living without any of their parents, girls attending special need education, immigrants, and girls who are not DTaP-IPV revaccinated. When targeting immigrants, the effort should focus on disseminating sufficient and understandable information about the Danish childhood vaccination program to the parents.

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.

There Is No Evidence That Inactivated COVID-19 Vaccines Increase Risks of Uveitis Flare

This is a retrospective study to investigate the impact of inactivated Coronavirus disease-2019 (COVID-19) vaccination on uveitis flare in patients with uveitis. Sixty patients that were regularly followed up for uveitis for at least two months after the last dose of inactivated COVID-19 vaccines were included in the vaccination group. Sixty patients with comparable characteristics of uveitis who had not received the COVID-19 vaccines were included in the control group. Uveitis flare within 30 days and 60 days after the vaccination in the vaccination group, or after a randomly selected date in the control group, were statistically compared. The flare rate was 16.7% (30 days) and 23.3% (60 days) in the vaccination group, while it was 13.3% (30 days) and 25% (15/60) in the control group. There was no statistical difference in the flare rate of uveitis between the two groups (p = 0.471 for 30 days, p = 0.347 for 60 days). Inactivated COVID-19 vaccination appeared not to increase the flare rate in patients with uveitis. Ophthalmologists should give proper and individualized recommendations based on the overall conditions of patients.

Safety of 4-valent human papillomavirus vaccine in males: a large observational post-marketing study

The 4-valent human papillomavirus (HPV) vaccine (4vHPV vaccine), Gardasil®, is indicated for the prevention of several HPV-related diseases. The objective was to assess the safety of 4vHPV vaccine administered to males as part of routine care. The study used a US health insurance claims database, and included males, age 9 to 26 years, who initiated 4vHPV between October 2009 and December 2016. General safety outcomes were identified using ICD diagnosis codes associated with emergency room visits and hospitalizations in the claims database in risk periods (Days 1–60 and Days 1–14 following vaccine administration) and self-comparison periods (Days 91–150 and 91–104 for the Days 1–60 and Days 1–14 analysis, respectively). Incidence rates (IRs) and relative rates (RRs) with 95% confidence intervals (CIs) were calculated comparing the risk and self-comparison periods. In this study, 114,035 males initiated 4vHPV vaccine and received 202,737 doses. Using the 60-day time window, 5 outcomes had significantly elevated RRs after accounting for multiple comparisons: ear conditions (RR 1.28, 95% CI 1.03–1.59); otitis media and related conditions (RR 1.65, 95% CI 1.09–2.54); cellulitis and abscess of arm (RR 2.17, 95% CI 1.06–4.72); intracranial injury (RR 1.23, 95% CI 1.01–1.50); and concussion (RR 1.29, 95% CI 1.05–1.59). A higher rate of allergic reactions was noted on the day of 4vHPV vaccine receipt compared to other vaccines (21.07 events per 10,000 doses, 95% CI 18.89–23.44 versus 11.44 per 10,000 doses, 95% CI 9.84–13.22). A higher incidence rate of VTE was observed following vaccination but this association was not significant (RR 2.17, 95% CI 0.35–22.74). The 4vHPV vaccine was associated with same-day allergic reactions as well as ear infections, intracranial injury, cellulitis, and concussion within 2 months after vaccination. While allergic reaction and cellulitis are consistent with the known safety profile of 4vHPV vaccine, the association of the other outcomes were determined by an independent Safety Review Committee to be most likely a result of activities common in adolescent males that coincide with the timing of vaccination and not directly related to vaccination itself.

Implications and Contributions: The study results support the general safety of routine immunization with 4vHPV vaccine among males to prevent HPV-related diseases and cancers.

Neurological and neuropsychological adverse effects of SARS-CoV-2 vaccines - where do we stand?

The devastating characteristic of COVID-19 pandemic calls for immediate and effective solutions to tackle it. Vaccines seem to be the only promising and effective way to fight against the novel coronavirus - even against new mutated variants. Because of the rapid development and distribution of numerous COVID-19 vaccines in different platforms, meticulous evaluation of vaccines' safety is more critical than ever - especially given the fact that most of the candidates have not completed the clinical phase. Therefore, to optimize the vaccines' safety and efficacy, it is highly important to carefully report and scientifically discuss the serious adverse effects following vaccination. In this respect, we discuss different neurological and neuropsychological adverse effects of COVID-19 vaccines including demyelinating diseases, Bell's palsy (BP), cerebrovascular complications, seizures, functional neurological disorders (FNDs), and some other rare adverse events, and hypothetical mechanisms which can lead to the reported side effects. Given the fact that the incidence of such events are rare and most of them are treatable, the current review aims to shed light on how much the relationship between COVID-19 vaccines and these complications can be reliable and provide an insight for future studies with much more meticulous methodologies to discuss the possible correlational or causal relationship between these complications and COVID-19 vaccines and elucidate whether or not the neurological side effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines can count as a considerable threat to public health.

Risk of Guillain-Barré syndrome after vaccination against human papillomavirus: a systematic review and meta-analysis, 1 January 2000 to 4 April 2020

BackgroundGuillain-Barré syndrome (GBS) is a rare autoimmune disease that can follow viral infections and has in a few cases been linked to vaccinations. Pre-licensure clinical trials did not observe an association between human papillomavirus (HPV) vaccination and GBS, a post-marketing study from 2017 reported an increased relative risk.AimWe assessed the risk of GBS after HPV vaccination through a systematic literature review and meta-analysis.MethodsWe searched Embase, MEDLINE and Cochrane for studies reporting on the risk of GBS after HPV vaccination in individuals aged ≥ 9 years, published between 1 January 2000 and 4 April 2020, excluding studies without a comparator group. Seven studies reporting relative effect sizes were pooled using random-effects meta-analysis. We assessed quality of evidence using the GRADE approach. Study protocol was registered (PROSPERO No. #CRD42019123533).ResultsOf 602 identified records, we included 25 studies. Based on over 10 million reports, cases of GBS were rare. In 22 studies no increased risk was observed, while in three studies a signal of increased risk of GBS after HPV vaccination was identified. Meta-analysis yielded a pooled random-effects ratio of 1.21 (95% CI: 0.60-2.43); I2 = 72% (95% CI: 36-88). This translates to a number needed to harm of one million to be vaccinated to generate one GBS case. Quality of evidence was very low.ConclusionsThe absolute and relative risk of GBS after HPV vaccination is very low and lacks statistical significance. This is reassuring for the already implemented vaccination programmes and should be used in respective communication activities.

Infections in temporal proximity to HPV vaccination and adverse effects following vaccination in Denmark: A nationwide register-based cohort study and case-crossover analysis

BACKGROUND

Public trust in the human papilloma virus (HPV) vaccination programme has been challenged by reports of potential severe adverse effects. The reported adverse symptoms were heterogeneous and overlapping with those characterised as chronic fatigue syndrome (CFS) and have been described as CFS-like symptoms. Evidence suggests that CFS is often precipitated by an infection. The aim of the study was to examine if an infection in temporal proximity to HPV vaccination is a risk factor for suspected adverse effects following HPV vaccination.

METHODS AND FINDINGS

The study was a nationwide register-based cohort study and case-crossover analysis. The study population consisted of all HPV vaccinated females living in Denmark, born between 1974 and 2006, and vaccinated between January 1, 2006 and December 31, 2017. The exposure was any infection in the period ± 1 month around time of first HPV vaccination and was defined as (1) hospital-treated infection; (2) redemption of anti-infective medication; or (3) having a rapid streptococcal test done at the general practitioner. The outcome was referral to a specialised hospital setting (5 national HPV centres opened June 1, 2015) due to suspected adverse effects following HPV vaccination. Multivariable logistic regression was used to estimate the association between infection and later HPV centre referral. The participants were 600,400 HPV-vaccinated females aged 11 to 44 years. Of these, 48,361 (9.7%) females had a hospital-treated infection, redeemed anti-infective medication, or had a rapid streptococcal test ± 1 month around time of first HPV vaccination. A total of 1,755 (0.3%) females were referred to an HPV centre. Having a hospital-treated infection in temporal proximity to vaccination was associated with significantly elevated risk of later referral to an HPV centre (odds ratio (OR) 2.75, 95% confidence interval (CI) 1.72 to 4.40; P < 0.001). Increased risk was also observed among females who redeemed anti-infective medication (OR 1.56, 95% CI 1.33 to 1.83; P < 0.001) or had a rapid streptococcal test (OR 1.45, 95% CI 1.10 to 1.93; P = 0.010). Results from a case-crossover analysis, which was performed to adjust for potential unmeasured confounding, supported the findings. A key limitation of the study is that the HPV centres did not open until June 1, 2015, which may have led to an underestimation of the risk of suspected adverse effects, but stratified analyses by year of vaccination yielded similar results.

CONCLUSIONS

Treated infection in temporal proximity to HPV vaccination is associated with increased risk for later referral with suspected adverse vaccine effects. Thus, the infection could potentially be a trigger of the CFS-like symptoms in a subset of the referred females. To our knowledge, the study is the first to investigate the role of infection in the development of suspected adverse effects after HPV vaccination and replication of these findings are needed in other studies.

Moving from nature to nurture: a systematic review and meta-analysis of environmental factors associated with juvenile idiopathic arthritis

Objectives

JIA is the most common paediatric rheumatic disease, thought to be influenced by both genetics and the environment. Identifying environmental factors associated with disease risk will improve knowledge of disease mechanism and ultimately benefit patients. This review aimed to collate and synthesize the current evidence of environmental factors associated with JIA.

Methods

Four databases (MEDLINE, Embase, Web of Science and Cumulative Index to Nursing and Allied Health Literature) were searched from inception to January 2020. Study quality was rated using the Newcastle-Ottawa Scale. Pooled estimates for each environmental factor were generated using a random-effects, inverse-variance method, where possible. The remaining environmental factors were synthesized in narrative form.

Results

This review includes 66 environmental factors from 39 studies (11 cohort and 28 case-control studies) over 45 years. Study sample sizes ranged from 41 to 1.9 million participants. Eight environmental factors from ten studies were meta-analysed. Caesarean section delivery was associated with increased JIA risk [pooled odds ratio (OR) 1.11, 95% CI: 1.01, 1.22]. Conversely, presence (vs absence) of siblings (pooled OR 0.60, 95% CI: 0.44, 0.81) and maternal prenatal smoking (pooled OR 0.70, 95% CI: 0.58, 0.84) were associated with decreased JIA risk.

Conclusion

This review identifies several environmental factors associated with JIA and demonstrates the huge breadth of environmental research undertaken over five decades. We also highlight the challenges of combining data collected over this period due to limited between study comparability, evolution in healthcare and social practices, and changing environment, which warrant consideration when planning future studies.

General Practitioner Attendance in Proximity to HPV Vaccination: A Nationwide, Register-Based, Matched Case-Control Study

Aim

This study aimed to describe and compare general practitioner (GP) attendance patterns in the years surrounding HPV-vaccination among cases suspected to experience adverse events and their matched controls in order to determine if a potential larger change in GP attendance among cases was observed in temporal relation to vaccination.

Methods

Register-based, matched case-control study. Cases were defined as women referred to specialized hospital settings (HPV-centers) for suspected adverse event between June 1st 2015 and December 31st 2015 (n=1458). Information on referral was obtained from the HPV-centers directly. Each case was matched with five controls on age at vaccination, region, time of first vaccine registration and total number of doses, resulting in a total study population of 8670 girls and women. Negative binomial regression analyses were used (i) to estimate mean yearly GP contacts among cases and controls, and (ii) to further investigate the relative difference in change in GP attendance following vaccination between cases and controls.

Results

Overall, cases displayed higher GP attendance than controls from five years before vaccination up until five years after. Compared to controls, cases increased their GP attendance more in the years following HPV vaccination, corresponding to a 40% increase in the incidence rate ratios (IRR) from before to after vaccination (ratio-IRR = 1.40 [1.36; 1.44]). The change occurred in close proximity to vaccination, and the pattern was the same independently of the year of vaccination. However, for the later vaccination years cases displayed an additional increase in their GP attendance around time of extensive media attention.

Conclusion

Girls and women being referred for suspected adverse events after HPV-vaccination changed their GP attendance pattern in close proximity to their first HPV-vaccination and not solely in temporal linkage to the onset of public debate.

Adverse events following HPV vaccination: 11 years of surveillance in Australia

BACKGROUND

Australia was the first country to implement a fully funded vaccination program with quadrivalent human papillomavirus vaccine (4vHPV) in 2007, including males from 2013. We examined adverse events (AE) following vaccination with 4vHPV from 11 years of post-marketing data, focusing on a period of enhanced surveillance and adverse events of special interest (AESI).

METHODS

AE following 4vHPV doses administered between April 2007 and December 2017 reported to Australia's national regulator, the Therapeutic Goods Administration, were examined; reports collected during enhanced surveillance in 2013 and 2014 were analyzed separately. Age and sex-specific rates, using denominator data from the national HPV vaccination register, were determined. Pre-specified AESI were identified using Medical Dictionary for Regulatory Activities (MedDRA®) Preferred Terms and examined in detail.

FINDINGS

Following nine million doses of 4vHPV vaccine administered in Australia, 4551 AE reports were identified. The crude reporting rate was 39.8 per 100 000 doses in the funded cohorts, excluding the enhanced surveillance period. The reported rate of syncope in 12 to 13-year-old males and females was 29.6 per 100 000 doses during enhanced surveillance and 7.1 per 100 000 doses during the remaining study period; rates of syncope were higher in younger compared to older adolescents. The rate of anaphylaxis (0.32 per 100 000 doses) was consistent with published rates. Other AESI including autoimmune disease, postural orthostatic tachycardia syndrome, primary ovarian insufficiency, Guillain-Barré syndrome, complex regional pain syndrome and venous thromboembolism, were reported at low rates and analysis did not reveal unexpected patterns that would suggest causal association.

INTERPRETATION

AESI, apart from syncope, were reported rarely. The higher rate of syncope among younger adolescents highlights the need for management protocols to prevent syncope-related injury. Analysis of this large, longitudinal dataset in a country with high vaccine uptake, including a period of enhanced surveillance, affirms the safety profile of 4vHPV.

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

BACKGROUND

Because of the limited number of subjects in prelicensure studies, autoimmune diseases and other rare adverse effects of vaccines may go undetected. Since 2006, millions of human papillomavirus (HPV) vaccine doses have been distributed and a considerable amount of postlicensure safety data has been generated. The objective of this study was to review available HPV postlicensure safety studies and to summarize risk estimates of autoimmune and other rare diseases.

METHODS

For this systematic review and meta-analysis, we searched literature databases to identify any postlicensure safety studies related to HPV vaccination and autoimmune adverse events from inception to April 16, 2019. Pooled risk estimates were computed using fixed- or random-effects models if at least 2 estimates per disease and per HPV vaccine were available.

RESULTS

Twenty-two studies met our inclusion criteria. The studies applied various methodologies and used different types of data sources and outcome definitions. Quadrivalent HPV vaccine (4vHPV) was most commonly assessed. Type 1 diabetes mellitus, immune thrombocytopenia purpura and thyroiditis diseases were most frequently reported. The meta-analysis was conducted on 35 diseases corresponding to 48 pooled risk estimates. Majority of the pooled estimates showed no significant effect (n = 43). Three negative (paralysis, immune thrombocytopenia purpura and chronic fatigue syndrome) and 2 positive (Hashimoto and Raynaud diseases) associations were detected.

CONCLUSION

Our study demonstrated an absence of clear association between HPV vaccines and autoimmune and other rare diseases. The review also highlights the need for more systematic collaborations to monitor rare safety adverse events.

Human papillomavirus vaccination and the risk of autoimmune disorders: A systematic review and meta-analysis

INTRODUCTION

Human papillomavirus (HPV) vaccination has been proven to effectively protect against HPV infection and infection-associated cancer. However, there are concerns about the relationship between HPV vaccination and the risk of autoimmune disorders (ADs). Therefore, we performed a systematic review and meta-analysis to comprehensively evaluate the relationship between HPV vaccination and ADs risk.

METHODS

To identify relevant studies, we conducted a systematic search in EMBASE and PubMed databases of scientific articles published through June 2018. Fixed or random effects models were adopted to estimate overall relative risk.

RESULTS

In total, 20 studies (12 cohort studies, 6 case-control studies, and 2 randomized controlled trials) involving more than 169,000 AD events were included in our meta-analysis. Our results show that HPV vaccination was not associated with an increased risk of subsequent ADs (odds ratio [OR] = 1.003, 95% confidence interval (CI): 0.95-1.06), particularly among those with a prior ADs (OR = 0.82, 95% CI: 0.7-0.96). Most of the subgroup analysis results based on the location or type of ADs were consistent with the overall results.

CONCLUSION

No evidence of an association between HPV vaccination and ADs was found. Given the low number of estimates for individual AD, additional and larger observational studies are needed to verify our findings.

Long term risk of developing type 1 diabetes after HPV vaccination in males and females

INTRODUCTION

Despite minimal evidence, public concerns that the human papillomavirus (HPV) vaccine can cause autoimmune diseases (AD) persist. We evaluated whether HPV vaccine is associated with a long-term increased risk of diabetes mellitus type 1 (DM1).

METHODS

This was a retrospective cohort study in which we identified all potential DM1 cases from Kaiser Permanente Northern California (KPNC) members who were between 11 and 26 years old any time after June 2006 through December 2015. We chart reviewed a random sample of 100 DM1 cases to confirm diagnosis and to develop a computer algorithm that reliably determined symptom onset date. Our DM1 Analysis Population comprised all individuals who met membership criteria and who were age and sex eligible to have received HPV vaccine. We adjusted for age, sex, race, Medicaid, and years of prior KPNC membership by stratification using a Cox multiplicative hazards model with a calendar timeline.

RESULTS

Our DM1 analysis included 911,648 individuals. Of 2613 DM1 cases identified, 338 remained in the analysis after applying our algorithm, HPV vaccine eligibility and membership criteria. Over the 10 years of the study period, comparing vaccinated with unvaccinated persons, we did not find an increased risk of DM1 associated with HPV vaccine receipt (hazard ratio 1.21, 95% Confidence Interval 0.94, 1.57).

CONCLUSIONS

We found no increased risk for development of DM1 following HPV vaccination. Our study provides reassurance that during the 10-year time period after HPV vaccine was introduced, there was no substantial increased risk for DM1 following HPV vaccination.

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.