Immunization: a global challenge for the 21st Century

Abstract

The 9th Canadian Immunization Conference was held on 5–8 December 2010 in Quebec City, Canada. Over 1000 academic, public health and vaccine industry scientists, nurses, pharmacists, physicians and policy makers attended the conference, which was organized by the Public Health Agency of Canada–Centre for Immunization Research and Respiratory Infectious Diseases in collaboration with the Canadian Association of Immunization Research and Evaluation, the Canadian Paediatric Society and the Canadian Public Health Association. Fresh from the pandemic influenza A H1N1 2009–2010 experience, in which Canada experienced a smaller Spring 2009 wave followed by a Fall wave that stretched public health prevention and healthcare system resources, conference attendees were given the chance to reflect on lessons from the perspective of communication strategies, vaccine effectiveness, safety and program delivery techniques, in one of six program streams devoted to H1N1. The five other streams were immunization in a global community, vaccine safety, new technologies, vaccine-specific issues and clinical practice. In this article, we summarize some of the key presentations from the six plenary sessions, 36 concurrent symposia and workshops, podium and poster presentations.

Immunization during the pandemic

Canadian public health authorities offered a universal influenza immunization program to all citizens in 2009–2010, using an AS03-adjuvanted monovalent low-dose influenza antigen (3.75 µg hemagglutinin) H1N1 vaccine (Arepanrix™, GlaxoSmithKline Biologicals). Uptake varied across the country, from up to 80% in high-risk persons in some provinces to an estimated 45% of the entire population, for what appears to have been an effective and safe vaccine.

Scheifele et al. from the Public Health Agency of Canada–Canadian Institutes of Health Influenza Research Network (PCIRN) compared hemagglutination inhibition (HAI) antibody responses in 6–35-month-old children to one or two doses of the adjuvanted pandemic influenza A H1N1 (pH1N1) vaccine, and found one dose elicited potentially protective titers (≥40) in 80% of seronegative children, with a second dose increasing geometric mean titers (GMT) tenfold and HAI titers to 100% [1]. Other PCIRN studies demonstrated the immunogenicity of one dose of vaccine in aboriginal adults with and without significant health conditions (fourfold antibody rise in 94% overall, and in 99% of unprimed subjects) [2] and compared one to two doses in adults with HIV. In the latter, one dose was immunogenic (HAI titers ≥40 in 76% with GMTs of 130 and a GMT ratio exceeding baseline by 11-fold at day 42); the two-dose series had significantly increased immunogenicity.

A PCIRN study of adults given delayed or concurrent trivalent seasonal influenza vaccine with pH1N1 vaccine found immune responses to pH1N1 and H3N2 were unaffected by concurrent immunization, but responses to B/Brisbane were lower in the group with delayed trivalent inactivated influenza vaccine receipt [3].

These scientific aspects of the influenza vaccine were complemented by sessions on risk communication during the pandemic, the media and governmental perspectives on the communication challenges, a plenary session comparing the Canadian, USA and WHO pandemic experiences, and a session on the relative strengths and weaknesses of different methodologies for vaccine effectiveness monitoring using the CDC and ECDC examples.

Global immunization issues

The inter-relatedness of populations across country boundaries was highlighted throughout the conference by the learning stream ‘Immunization in the global community’. Using the example of the 12 January 2010 Haitian earthquake, which claimed over 200,000 lives (including 300 healthcare workers), a session on ‘Vaccines for travel and disasters’ identified the risks for vaccine-preventable diseases (VPDs) such as cholera, the protection required for aid workers, and the unique risks of VPDs in travelers returning to a homeland to visit friends and relatives in a disaster-affected area.

A session on global initiatives to build or strengthen the capacity of national immunization technical advisory groups (e.g., Canada’s National Advisory Committee on Immunization or the US Advisory Committee on Immunization Practices) evidence-based decision-making methods highlighted some of the professional development tools and training that are available for policy makers and recommendation committee members. Representatives from the Supporting Independent Immunization and Vaccine Advisory Committees [101], which hosts a website with training materials for those making immunization recommendations, and the PanAmerican Health Organization ProVac initiative, reviewed the epidemiological, economic, financial and logistical factors that are considered when a country considers a new vaccine. A representative from the Ecuadorian Ministry of Public Health explained how these factors influenced decision-making with regard to rotavirus and pneumococcal vaccines in Ecuador. The needs of new immigrants and refugees were highlighted in a session focussing on childhood VPD in adults in whom, for example, the risk of varicella infection is higher than in Canadian-born individuals [4]. The Canadian Clinical Preventive Guidelines for Primary Health Care of Immigrants and Refugees were introduced as an evidence-based source for care of this population [5].

Vaccine safety

In the Dr John Waters Memorial Lecture, given by Scott Halperin on ‘Responding to the global anti-vaccination movement: ‘thinking globally, acting locally’, it was noted that vaccination is one of the greatest public health achievements of the 20th Century and most vaccines in use are cost saving or have favorable cost–effectiveness profiles. Halperin argued that there is actually no organized anti-vaccination ‘movement’, instead, anti-vaccinationism has been around since the use of cowpox for smallpox prevention in Edward Jenner’s era. In 1840, England’s Vaccination Act outlawed variolation, and in 1853 mandated vaccination against smallpox. Opposition including the Anti-vaccination League Against Compulsory Vaccination, led to incorporation of the conscientious objector clause into subsequent legislation. In North America in the late 1880s similar leagues sprang up but vaccine legislation was upheld in the courts. In the 1970s in the UK, anti-vaccination was focused on an association between encephalopathy and whole-cell pertussis vaccine, a concern that was subsequently laid to rest by large-scale studies. Similar concerns arose in the USA stimulated by publications such as Shot in the Dark[6] and led to the development of the vaccine injury compensation scheme. In the late 1990s, Andrew Wakefield attributed gastrointestinal illness and neurodevelopmental abnormalities to measles-containing vaccine; these findings have now been thoroughly discredited. The developing world is not immune to these events, as evidenced by Nigeria’s mistrust of polio vaccine because of unfounded concerns that they cause infertility. Three quarters of Canadians use the internet regularly as an information source, with more than half believing that this is a credible source. Search engines turn up anti-vaccination sites when using the term ‘vaccination’ whereas ‘immunization ‘ is associated with authoritative sites. Media coverage of these issues tends to give both sides equal air time. Halperin advised the public health community to ensure that their websites provide accessible information that is readable, navigable, up to date and geared to both the general public and and to practitioners. For parents needing more information and for primary care practitioners he recommended books such as Ron Gold’s Your Child’s Best Shot[7] and Paul Offit’s Vaccines: What You Should Know[8]. Public health should not speak from a script, but instead participate in discourse with academics, basic scientists, practitioners, and the public. The key is to respond quickly, address specific issues, but be aware of the opposition.

In a concurrent session on risk communication, speakers noted that it’s not enough to present information on vaccines to parents, but to also show empathy. Most parents need information on disease risks, vaccine benefits and side effects, but without detailed statistics, such as relative risks and percentages. One speaker outlined a strategy used successfully with parents reluctant to immunize their child because of anti-vaccination messages presented by a prominent media personality, in which the parent is asked: “If your child had a brain tumour, who would you like to operate on your child? That media personality or a pediatric neurosurgeon?” Typically the parent chooses the neurosurgeon because, “they’ve spent years of their lives studying how to do this”, and the point is made. Risk communication in aboriginal communities, such as Canadian First Nations, was presented in this concurrent session. The importance of building trustful relationships, presence in the community, providing information in a timely manner, nipping rumors in the bud, and use of visual tools was noted. Family physicians (General practitioners) have been repeatedly identified by the public in surveys as the preferred source of advice on clinical prevention. Advice must be tailored to the needs of the patient/family, rather than being generic. In one speaker’s view, the media and members of certain health professions including chiropractic, naturopathy and homeopathy were sometime unsupportive of immunization regardless of the weight of the scientific evidence.. The role of the professional regulatory bodies in accounting for the scientific integrity of their membership is unclear and issues can become politicized. A Washington State study found that parents who seek care from a naturopath or chiropractor are less likely to vaccinate their children.

Sustaining the immunization community

David Scheifele of the University of British Columbia (BC, Canada), in his distinguished lecture in Canadian immunization presentation, asked if the Canadian Vaccine Research enterprise can sustain the challenges of globalization. Scheifele observed that as the number of vaccine manufacturers has decreased with the purchase and consolidation of smaller companies, the number of clinical vaccine studies undertaken in Canada has diminished. He argued that the absence of core government funding for clinical trial centers in Canada, in contrast to the USA (where a network has been funded for two decades), threatens the sustainability of Canada’s ability to perform vaccine evaluation. He highlighted the success of the PCIRN network, a recently funded pandemic influenza project involving over 80 influenza investigators across Canada, in launching rapid clinical trials and vaccine safety and effectiveness research in the past 18 months, which demonstrates the resourcefulness, flexibility and potential of the Canadian vaccine research community.

The conference itself was employed as an opportunity to translate and disseminate knowledge by activities that mentor and educate students and practitioners about the importance of immunization and vaccinology through a poster contest, awards for scientific presentations and travel bursaries. The Canadian Immunization Poster Contest engages middle school children (Grade 5) and their teachers, by providing a teachers toolkit on immunization with math, art and other curricular material through the website of the Canadian Coalition for Immunization Awareness [102]. The students submit art posters based on an immunization theme, and the winning entries are published in a calendar and immunization promotional posters. The overall winner attends the conference with his/her parents/guardians to receive a prize; the 2010 winning entry can be found at the Canadian Immunization Poster Contest website [103]. Four university students were awarded travel bursaries to present their research related to VPD/immunization, and participate in a Canadian Association of Immunization Research and Evaluation research workshop [104]. In addition, a travel bursary program allows recipients with limited funding who intend to share the knowledge gained from their attendance with their organization or community. The poster and exhibit sessions permit presentation of practical aspects of program implementation and qualitative aspects of immunization practice, along with the traditional components such as vaccine efficacy, immunogenicity and effectiveness. Two ‘named lectures’ recognize those who have made outstanding career contributions to immunization. This year, Halperin and Scheifele were presented the ‘Dr. John Waters Memorial Lecture’ and the ‘Distinguished Canadian Lecture in Immunization’, respectively.

Abstracts from the conference were published in the Canadian Journal of Medical Microbiology and are available online at [105].

Financial & competing interests disclosure

Joanne M Langley serves as the chair of the National Advisory Committee on Immunization, which advises the Public Health Agency of Canada on vaccine use in Canadians from 2007–2011, and has received funding for research from the Canadian Institutes of Health Research, the Public Health Agency of Canada and the following vaccine manufacturers: GlaxoSmithKline, Dymaxion, Sanofi-Pasteur, Novartis and Wyeth. Monika Naus serves as the provincial-territorial co-chair of the Canadian Immunization Committee, which oversees a variety of supporting activities in immunization programs including the development of statements for provincial/territorial consideration in decision-making related to new vaccines in Canada. She is involved in such decision-making in BC, Canada. She has received funding for research from the BC Immunization Committee but declines funding from the vaccine industry. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.