Human papilloma virus immunization in adolescent and young adults: a cohort study to illustrate what events might be mistaken for adverse reactions

Optimizing immunization in pediatric special risk groups

This article analyzes the current recommended practices and evidence in the immunization of pediatric 'special risk groups'. Special risk group patients are at higher risk of vaccine-preventable diseases and hence require additional strategies to maximize protection against these diseases. The special risk groups include those with an underlying chronic disease, some of whom are on immunosuppressive therapy to treat that condition. The article uses four special risk groups (acute lymphoblastic leukemia; preterm birth; juvenile idiopathic arthritis; and inflammatory bowel disease), to highlight the management considerations and potential vaccination strategies. The risks, benefits and timing of vaccination in the setting of immunosuppression require detailed discussion with treating clinicians, in particular the use of live-attenuated vaccines. The immunogenicity of vaccines in these special risk groups helps provide the evidence base for their immunization guidelines. Protection can include 'cocooning' (i.e., ensuring appropriate immunizations within the immediate family; e.g., varicella, influenza and pertussis vaccination). Improving timeliness and minimizing missed opportunities to vaccinate individuals with these special risk conditions will also optimize protection from vaccine-preventable diseases.

Disease-specific adverse events following nonlive vaccines: a paradoxical placebo effect or a nocebo phenomenon?

Vaccines can cause adverse reactions (AR), i.e. adverse events following immunization (AEFIs) due to the vaccine, such as local reactions or fever. In addition, live attenuated vaccines which replicate in vaccinees can cause disease-specific AR, e.g. measles-like rash following measles vaccination. However, nonlive vaccines because they are inactivated and they do not replicate in vaccinees, are not likely to cause disease-specific AR. The aim of the study was to assess whether safety signals could be generated by an undescribed bias in spontaneous reporting of disease-specific AEFIs with nonlive vaccines. All AEFIs of Sanofi Pasteur MSD vaccines spontaneously reported in France from January 2000 to June 2010, coded according to MedDRA terms and collected in the company's pharmacovigilance database were analyzed. Vaccine-event pairs of interest were selected a priori. The disproportionality reporting rate methodology was used, comparing the proportion of a given event reported following a given vaccine to its proportion reported following all other studied vaccines. The Reporting Odds Ratio (ROR) was used for signals detection for each vaccine-event pair selected. A total of 33,275 AEFIs were analyzed. The calculated ROR showed a statistically disproportionate reporting rate and generated false safety signals for almost all the pairs tested. Three nonlive vaccine pairs were striking: gynaecological symptoms and the quadrivalent human papillomavirus (qHPV) vaccine; trismus and tetanus vaccines; hepatobiliary disorders and hepatitis B vaccines. In conclusion we have identified a new vaccine AE spontaneous reporting bias: "disease-specific adverse events following nonlive vaccines", showing that vaccinees and healthcare professionals tend to report preferentially the symptoms of the disease against which the nonlive vaccine was administered. We suggest that bias is subordinate to a paradoxical placebo effect and/or a nocebo phenomenon.

[Resistance to immunization]

Despite a well documented efficacy and a generally good adhesion of a large majority of the lay population and health care professionals as well, immunization is still the object of controversies. It affects several vaccines against hepatitis B, influenza, BCG, pertussis and measles. In most cases, polemics on vaccination result from a temporal association between a vaccination and the revelation of a serious disease, when the immunization is performed at the peak of incidence of the disease. Controversies can also be initiated by scientific publications, even though these are often biased, by a misinterpretation or the absence of official positions from the health care authorities, or by justice decisions, whose criteria differ from the scientists' ones and are therefore difficult to understand for the lay public. Furthermore, the scientific demonstration of the exclusion of a risk is difficult to obtain. In the past, it appeared to be very difficult to stop controversies. Improving the communication is the main issue, towards lay public as well as health care professionals. This implies to learn how to better use the media, to motivate and educate professionals who administer vaccine, and anticipate the eventuality of a temporal relationship between vaccination and occurrence of a serious disease by an improved management of the pharmacovigilance system.

[Prophylactic and therapeutic vaccines against human papilloma virus]

Infection with human papilloma virus (HPV) has been identified as the cause of recurrent papillomatosis and of a subgroup of squamous cell carcinomas of the head and neck. A change in prevalence of these lesions, especially for oropharyngeal carcinoma, can be expected as a consequence of the introduction of prophylactic HPV vaccines for young women, targeting the most frequent high- and low-risk HPV subtypes. Vaccination for the major low-risk HPV types has proven to be highly effective against genital warts and activity against papillomatosis can be expected. The possibilities of prophylactic HPV vaccination as well as new developments and the rationale for therapeutic vaccines are discussed on the basis of the current literature.

Human papillomavirus vaccine safety in Australia: experience to date and issues for surveillance

Australia was one of the first countries to licence a quadrivalent human papillomavirus (HPV) vaccine, rapidly followed by a federally funded program of universal vaccination of a broad age group of females through schools (12 to 18 years) and primary care (19 to 26 years). As of August 2009, more than 5.8 million doses of Gardasil((R)) (quadrivalent; Merck, New Jersey, USA) have been distributed in Australia and a total of 1394 suspected adverse events following immunisation (AEFI) have been reported to the passive surveillance system. Most reports are of common and expected reactions. Case series of more uncommon and serious AEFI, both known to be potentially vaccine related (anaphylaxis, conversion disorders and lipoatrophy) and otherwise (multiple sclerosis and pancreatitis) have been published.

Clinical trial and post-licensure safety profile of a prophylactic human papillomavirus (types 6, 11, 16, and 18) l1 virus-like particle vaccine

BACKGROUND

We describe the safety of the human papillomavirus (HPV)-6/11/16/18 vaccine using updated clinical trial data (median follow-up time of 3.6 years) and summarize up to 3 years of post-licensure surveillance.

METHODS

In 5 clinical trials, 21,480 girls/women aged 9 to 26 years and boys aged 9 to 16 years received >or=1 dose of HPV-6/11/16/18 vaccine or placebo. All serious and non-serious adverse experiences (AEs) and new medical conditions were recorded for the entire study period(s). As of June 2009, >25 million doses of HPV-6/11/16/18 vaccine had been distributed in the United States with >50 million doses globally. Post-licensure safety as summarized by the Centers for Disease Control and Prevention using the United States Vaccine Adverse Event Reporting System database is also reported.

RESULTS

Eight subjects experienced a treatment-related serious AE (0.05% vaccine; 0.02% placebo). Of 18 deaths (0.1% vaccine; 0.1% placebo), all were considered unrelated to study treatment. New medical conditions which were potentially consistent with autoimmune phenomena were reported in 2.4% of both vaccine and placebo recipients. Pain, the most common injection-site AE, occurred more frequently with vaccine (81% vaccine; 75% placeboaluminum; 45% placebo-saline). No differences were seen in the incidence of the most common non-serious AEs-headache and pyrexia. The Vaccine Adverse Event Reporting System has received 14,072 reports for the HPV-6/11/16/18 vaccine since licensure, with only 7% being serious AEs, about half the average reported for licensed vaccines in general.

CONCLUSIONS

HPV-6/11/16/18 vaccination was associated with more injection-site pain than placebo but similar incidences of systemic and serious AEs and new medical conditions potentially consistent with autoimmune phenomena. Based on review of post-licensure safety information, the benefits of vaccination to prevent the majority of genital tract precancers and cancers continue to far outweigh its risks.

Monitoring the control of human papillomavirus (HPV) infection and related diseases in Australia: towards a national HPV surveillance strategy

This paper describes a possible multifaceted approach to human papillomavirus (HPV) related surveillance in Australia following implementation of a national HPV vaccination program. We describe eight main components: monitoring of vaccine coverage, vaccine safety, type-specific HPV infection surveillance, cervical cytology (Pap screening) coverage and screen detected lesion prevalence, cervical cancer incidence and mortality, genital wart incidence, incidence of recurrent respiratory papillomatosis, and knowledge, attitudes and beliefs about HPV and HPV vaccination. Australia is well placed to monitor the impact of its HPV vaccination program as well as to measure vaccine effectiveness with existing HPV vaccines, cervical screening and cancer registries.

"Prepandemic" immunization for novel influenza viruses, "swine flu" vaccine, Guillain-Barré syndrome, and the detection of rare severe adverse events

The availability of immunogenic, licensed H5N1 vaccines and the anticipated development of vaccines against "swine" influenza A(H1N1) have stimulated debate about the possible use of these vaccines for protection of those exposed to potential pandemic influenza viruses and for immunization or "priming" of populations in the so-called "prepandemic" (interpandemic) era. However, the safety of such vaccines is a critical issue in policy development for wide-scale application of vaccines in the interpandemic period. For example, wide-scale interpandemic use of H5N1 vaccines could lead to millions of persons receiving vaccines of uncertain efficacy potentially associated with rare severe adverse events and against a virus that may not cause a pandemic. Here, we first review aspects of the 1976 National Influenza Immunization Programme against "swine flu" and its well-documented association with Guillain-Barré syndrome as a case study illustration of a suspected vaccine-associated severe adverse event in a mass interpandemic immunization setting. This case study is especially timely, given the recent spread of a novel influenza A(H1N1) virus in humans in Mexico and beyond. Following this, we examine available safety data from clinical trials of H5N1 vaccines and briefly discuss how vaccine safety could be monitored in a postmarketing surveillance setting.

Pediatric central nervous system inflammatory demyelination: acute disseminated encephalomyelitis, clinically isolated syndromes, neuromyelitis optica, and multiple sclerosis

PURPOSE OF REVIEW

We review the recent consensus definitions for acute disseminated encephalomyelitis,clinically isolated syndromes, neuromyelitis optica, and multiple sclerosis (MS) in children. We also discuss the importance of clinically defined consistency, the need for biomarker-based patient delineation, the likelihood of subsequent MS diagnosis following acute demyelination, and current therapeutic options.

RECENT FINDINGS

Studies of children after a first episode of demyelination have identified disease onset in adolescence, intrathecal oligoclonal bands and optic neuritis as associated with a higher MS risk, whereas prepubertal onset, presence of polyfocal features with encephalopathy, and transverse myelitis have been associated with a lower risk of subsequent MS. The relapsing-remitting form of MS accounts for over 96% of all MS in children. Neuromyelitis optica appears to be a distinct clinical and biological entity for which neuromyelitis optica IgG provides a high degree of specificity. Neuroimaging plays a key role in the diagnosis of acute demyelination, and serial imaging can provide evidence of lesion dissemination in time that can confirm a diagnosis of MS even in the absence of clinical relapse.

SUMMARY

Although clinical definitions, increased awareness, and MRI have contributed to the increasing identification of acute demyelination and MS in children, challenges remain in predicting MS risk. Identification of reliable biomarkers or application of more advanced neuroimaging techniques would serve as invaluable tools to distinguish monophasic demyelination from the first attack of MS.

Multiple Evanescent White Dot Syndrome After Vaccination for Human Papilloma Virus and Meningococcus

Multiple evanescent white dot syndrome is a rare chorioretinopathy causing transitory vision loss, usually in females and generally in one eye. In 2007, widespread vaccination of older children against human papilloma virus and meningococcus was recommended by the Centers for Disease Control and Prevention. A 17-year-old girl presented with multiple evanescent white dot syndrome 1 month after receiving these two vaccinations.

[Nobel price for vaccination against cervical cancer: current data and guidelines]

Harald zur Hausen received the Nobel price for Medicine in 2008 for his seminal research on human papilloma viruses and their association with anogenital diseases. On the basis of his work highly effective prophylactic vaccines have been developed. Clinical studies have shown nearly 100% seroconversion and an excellent safety profile as well as greater than 96% efficacy against HPV infection and premalignant dysplasia, induced by HPV types covered by the vaccine. Due to the convincing data of phase II and III clinical trials the introduction of HPV vaccination was recommended by health authorities and scientific committees in Germany. The development and availability of guidelines and evidence-based recommendations should support the introduction of the vaccine and widespread vaccination.

Analysis of adverse events of potential autoimmune aetiology in a large integrated safety database of AS04 adjuvanted vaccines

Newly licensed vaccines against human papillomavirus (HPV) and hepatitis B (HBV), and several vaccines in development, including a vaccine against genital herpes simplex virus (HSV), contain a novel Adjuvant System, AS04, composed of 3-O-desacyl-4' monophosphoryl lipid A and aluminium salts. Given the background incidence of autoimmune disorders in some of the groups targeted for immunisation with these vaccines, it is likely that autoimmune events will be reported in temporal association with vaccination, even in the absence of a causal relationship. The objective of this integrated analysis was to assess safety of AS04 adjuvanted vaccines with regard to adverse events (AEs) of potential autoimmune aetiology, particularly in adolescents and young adults. All randomised, controlled trials of HPV-16/18, HSV and HBV vaccines were analysed in an integrated analysis of individual data (N = 68,512). A separate analysis of the HPV-16/18 vaccine trials alone was also undertaken (N = 39,160). All data were collected prospectively during the vaccine development programmes (mean follow-up of 21.4 months), and included in the analysis up to a pre-defined data lock point. Reporting rates of overall autoimmune events were around 0.5% and did not differ between the AS04 and control groups. The relative risk (AS04/control) of experiencing any autoimmune event was 0.98 (95% confidence intervals 0.80, 1.21) in the integrated analysis and 0.92 (0.70, 1.22) in the HPV-16/18 vaccine analysis. Relative risks calculated overall, for disease category or for individual events were close to 1, and all confidence intervals around the relative risk included 1, indicating no statistically significant difference in event rates between the AS04 and control groups. This integrated analysis of over 68,000 participants who received AS04 adjuvanted vaccines or controls demonstrated a low rate of autoimmune disorders, without evidence of an increase in relative risk associated with AS04 adjuvanted vaccines.

Human papillomavirus immunisation of adolescent girls and anticipated reporting of immune-mediated adverse events

Determining incidence rates of potential adverse events before and after an immunisation programme is initiated, provides a useful framework for the evaluation of vaccine safety concerns. Human papillomavirus vaccination (HPV) of adolescent girls has recently been introduced in Denmark. Using a nationwide hospitalisation registry we estimated incidence rates of immune-mediated disorders before HPV vaccination in a cohort of 418,289 Danish girls aged 12-15 years. We further estimated the expected number of cases of immune-mediated disorders occurring in temporal relationship to a hypothetical HPV vaccination schedule purely by chance. Our results and analytical approach provides a framework for the evaluation of adverse event reports following immunisation of adolescent girls.

Human papillomavirus vaccine and adolescents

PURPOSE OF REVIEW

The present review describes recent advances in our understanding about the epidemiology of human papillomavirus infection among female adolescents and describes several adolescent-specific issues related to administering human papillomavirus vaccines.

RECENT FINDINGS

National estimates demonstrate that human papillomavirus infection is most prevalent among adolescents and young adults. Parents, patients, and providers have a high interest in vaccination against this virus, but current patterns of adolescent healthcare utilization suggest that changes in adolescent preventive care delivery may be needed to provide these vaccines in a timely manner. Debate over whether adolescents should be legally allowed to self-consent to vaccination is another issue that remains unresolved and could have a substantial impact on vaccination rates. Legislation on school entry requirements related to human papillomavirus vaccination has been introduced in many states as a mechanism to circumvent some of these concerns, but the details of this legislation and its effect on adolescent vaccine utilization remain to be determined.

SUMMARY

Female adolescents are at a high risk for human papillomavirus infection and are likely to derive significant benefits from vaccination against this virus. However, administering human papillomavirus vaccines to this age group will require providers to be familiar with several issues unique to the adolescent population.

Hypersensitivity reactions to human papillomavirus vaccine in Australian schoolgirls: retrospective cohort study

OBJECTIVE

To describe the outcomes of clinical evaluation, skin testing, and vaccine challenge in adolescent schoolgirls with suspected hypersensitivity to the quadrivalent human papillomavirus vaccine introduced in Australian schools in 2007.

DESIGN

Retrospective cohort study.

SETTING

Two tertiary paediatric allergy centres in Victoria and South Australia, Australia.

PARTICIPANTS

35 schoolgirls aged 12 to 18.9 years with suspected hypersensitivity reactions to the quadrivalent human papillomavirus vaccine.

MAIN OUTCOME MEASURES

Clinical review and skin prick and intradermal testing with the quadrivalent vaccine and subsequent challenge with the vaccine.

RESULTS

35 schoolgirls with suspected hypersensitivity to the quadrivalent human papillomavirus vaccine were notified to the specialised immunisation services in 2007, after more than 380 000 doses had been administered in schools. Of these 35 schoolgirls, 25 agreed to further evaluation. Twenty three (92%) experienced reactions after the first dose. Thirteen (52%) experienced urticaria or angio-oedema, and of these, two experienced anaphylaxis. Thirteen had generalised rash, one with angio-oedema. The median time to reaction was 90 minutes. Nineteen (76%) underwent skin testing with the quadrivalent vaccine: all were skin prick test negative and one was intradermal test positive. Eighteen (72%) were subsequently challenged with the quadrivalent vaccine and three (12%) elected to receive the bivalent vaccine. Seventeen tolerated the challenge and one reported limited urticaria four hours after the vaccine had been administered. Only three of the 25 schoolgirls were found to have probable hypersensitivity to the quadrivalent vaccine.

CONCLUSION

True hypersensitivity to the quadrivalent human papillomavirus vaccine in Australian schoolgirls was uncommon and most tolerated subsequent doses.

Anaphylaxis following quadrivalent human papillomavirus vaccination

BACKGROUND

In 2007, Australia implemented the National human papillomavirus (HPV) Vaccination Program, which provides quadrivalent HPV vaccine free to all women aged 12-26 years. Following notification of 7 presumptive cases of anaphylaxis in the state of New South Wales, Australia, we verified cases and compared the incidence of anaphylaxis following HPV vaccination to other vaccines in comparable settings.

METHODS

We contacted all patients with suspected anaphylaxis and obtained detailed histories from telephone interviews and a review of medical records. A multidisciplinary team determined whether each suspected case met the standardized Brighton definition. Some participants also received skin-prick allergy testing for common antigens and components of the HPV vaccine.

RESULTS

Of 12 suspected cases, 8 were classified as anaphylaxis. Of these, 4 participants had negative skin-prick test results for intradermal Gardasil. From the 269 680 HPV vaccine doses administered in schools, 7 cases of anaphylaxis were identified, which represents an incidence rate of 2.6 per 100 000 doses (95% CI 1.0-5.3 per 100 000). In comparison, the rate of identified anaphylaxis was 0.1 per 100 000 doses (95% CI 0.003-0.7) for conjugated meningococcal C vaccination in a 2003 school-based program.

INTERPRETATION

Based on the number of confirmed cases, the estimated rate of anaphylaxis following quadrivalent HPV vaccine was significantly higher than identified in comparable school-based delivery of other vaccines. However, overall rates were very low and managed appropriately with no serious sequelae.

The public perception of the value of vaccines - the case of Switzerland

Aim

In this original article, we seek to analyse the environment in which immunisation policies are adopted and, more specifically, the way the public perception of vaccines influences decision-making, by looking more closely at the case of Switzerland.

Subjects and methods

Historical and present-day examples of attitudes towards immunisation and specific vaccines, both on the part of the public and of health-care workers, are reviewed.

Results

Decision-making with regard to vaccine policy implementation has been and is still most often driven by fear: fear of disease (when perceived as rampant and/or dangerous), but also fear of vaccine-associated adverse events (when the disease is less or no longer “visible”). However, methodology for introducing evidence-based immunisation policies exists and can be used by public health authorities, while vaccination information systems (such as the Swiss InfoVac) have proven their usefulness in providing trustworthy, peer-based knowledge to health-care workers.

Conclusion

Only information based on clear, evidence-based data gathered and analysed according to solid methodological criteria coupled with adequate information of health-care workers (and thus patients) can ensure in future the implementation of scientifically coherent, publicly acceptable, and equitable immunisation policies.

Current awareness: Pharmacoepidemiology and drug safety

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.