Helen Petousis-Harris

Vaccine injection technique and reactogenicity--evidence for practice.

There are inconsistencies in recommendations and practice with regards to how best to administer vaccines. This review evaluates the literature on intramuscular vaccine administration technique in primarily paediatric populations and concludes from available evidence which aspects of vaccine administration are associated with reactogenicity. Variables with best evidence to support practice to reduce reactogenicity were: Site of injection--less reactogenicity has been noted when the buttock is used rather than the thigh; tissue (muscle or subcutaneous)--less reactions are noted when vaccine is administered intramuscularly rather than subcutaneously; length of needle--longer needles are associated with less reactogenicity. Angle of injection--a 90 degrees angle is associated with less reactogenicity than a reduced angle. Despite a need for more empirical studies, there appears to be several vaccine administration techniques relating to needle angle, length, site and depth of injection that result in fewer reactions and these could be considered for public health policy, in conjunction with immunogenicity.

Infant outcomes after exposure to Tdap vaccine in pregnancy: an observational study.

Objective Pertussis vaccination during pregnancy has recently been recommended in both the USA and UK to prevent pertussis infection in infants. While there are no apparent safety concerns about the administration of Tdap vaccine during pregnancy, there is only limited safety data available. We aimed to closely monitor infants exposed to Tdap during pregnancy to look for any adverse outcomes that may be attributable to the vaccine. Design This was a prospective observational study, collecting information to evaluate the safety of Tdap vaccine for infants exposed during pregnancy. Infants were followed for between 6 and 12 months after birth, with 84% completing 12 months of follow-up. Information was obtained from objective sources including routine health visits and vaccination records wherever possible, as well as frequent parental reports. Setting The Canterbury region of New Zealand. Patients A cohort of 403 infants whose mothers had received Tdap vaccine. Main outcome measures Gestational age at birth, growth parameters, congenital anomalies, immunisation status and timeliness of immunisation, development of pertussis infection. Results There were no significant differences in birth weight, gestational age at birth, congenital anomalies or infant growth as compared with baseline population data. Infants of mothers who had received the vaccine were more likely to receive their vaccinations on time during infancy. No cases of pertussis occurred in this cohort despite high rates of disease in the community. We have not found any adverse events attributable to vaccine exposure. Conclusions These data add to the growing pool of evidence that the administration of Tdap vaccine during pregnancy is an appropriate strategy for reducing the burden of pertussis in infants. Clinical trial registration Australia New Zealand Clinical Trials Registry ACTRN12613001045707.

Recruitment of practices in primary care research: the long and the short of it

OBJECTIVE To determine factors that facilitated or hindered recruitment of general practices into a large New Zealand primary care project that aimed to determine general practice characteristics of immunization coverage. METHODS The project had a multi-level recruitment strategy requiring recruitment of randomly selected practices before randomly selecting GPs, practice nurses and caregivers of children enrolled at those practices. Detailed quantitative and qualitative recruitment data were recorded on an access database. Post-recruitment, recruiters underwent semi-structured interviews. Analysis was mixed method, with triangulation of descriptive statistics of the number of calls and time course to recruitment and general inductive thematic analysis of qualitative data. RESULTS Identifying key decision makers and how individual practice processes work can save significant recruitment time. Factors identified as assisting practice recruitment included using a personal approach from doctor to doctor, getting buy-in from all practice staff, streamlining the research process to minimize disruption to the practice and flexibility to accommodate practices. CONCLUSIONS The task of recruiting should not be underestimated. Adequate time and resource need to be allocated from the onset. Long periods where practices have no added burdens such as audits, mass vaccination programmes or influenza season are unlikely, therefore there are always considerable challenges in recruiting practices for research. Remaining flexible to individual practice styles and influences and acknowledging the commitment of participants is important.

Factors associated with immunisation coverage and timeliness in New Zealand

BACKGROUND Immunisation coverage in New Zealand is lower than what is necessary to prevent large epidemics of pertussis. Primary care is where most immunisation delivery occurs. General practices vary in their structure and organisation, both in a general sense and specifically with respect to immunisation delivery. AIM To identify the structural and organisational characteristics of general practices associated with higher immunisation coverage and more timely immunisation delivery. DESIGN OF STUDY A random sample of practices during 2005 and 2006. SETTING General practices in the Auckland and Midland regions, with over-sampling of indigenous Maori governance practices. METHOD Practice immunisation coverage and timeliness were measured. Primary care practice characteristics relevant to immunisation delivery by the practice were described. Associations of these practice characteristics with higher practice immunisation coverage and more timely immunisation delivery were determined. RESULTS A total of 124 (61%) of 205 eligible practices were recruited. A median (25th to 75th centile) of 71% (57-77%) of registered children at each practice were fully immunised, and 56% (40-64%) had no immunisation delay. In multivariate analyses, both practice immunisation coverage (P<0.001) and timeliness (P<0.001) decreased with increased social deprivation. After adjustment for socioeconomic deprivation, region, and governance, immunisation coverage and timeliness were better at practices that enrolled children at a younger age (coverage: P = 0.002; timeliness P = 0.007), used one of the four available practice management systems (coverage: P<0.001; timeliness: P = 0.006), and had no staff shortages (coverage: P = 0.027; timeliness: P = 0.021). CONCLUSION Practice immunisation coverage and timeliness vary widely in New Zealand. General organisational and structural aspects of general practices are key determinants of general practice immunisation delivery.

Immunization in the print media - perspectives presented by the press.

New Zealand (NZ) has low immunization coverage for a Western country. Media coverage, including views and content expressed on editorial pages, can affect immunization uptake both positively and negatively. The objectives of this research were to analyze the content of written media in 2001 and 2003 throughout NZ in terms of vaccination and vaccine preventable diseases from a supporting, neutral, or opposing perspective; how vaccination and vaccine-preventable diseases are presented to their target audiences; and changes over time with possible influences on these changes. Print media clippings were analyzed from 400 national publications in 2001 and 2003 for references to immunization and vaccine-preventable diseases. Articles were coded as supportive, neutral, or opposing immunization. During two 12-month periods, 2,113 articles, including letters to the editor and opinion columns were analyzed: 1,228 from 2001; and 885 from 2003. Thirty-three percent (704) were classified as “supportive,” 17% (362) as “opposing,” and 51% (1,081) as “neutral.” Articles and perspectives in the media opposed to immunization were significantly more plentiful in 2001 than in 2003 (328/1,228; 27% vs. 34/885; 4% of all immunization media; χ2 = 189.46; p = <0.0001; df = 1). References to specific vaccines and disease were examined. During this study period there were high-profile infectious disease and vaccine issues that may have shaped the differences observed in the media clippings. This study indicates an overall positive trend toward reduction in alarmist anti-immunization messages in media. Strategies implemented by the Immunization Advisory Centre to counter misinformation may have contributed to reduction in anti-immunization messages.

Safety of Tdap vaccine in pregnant women: an observational study

Objectives Actively recruit and intensively follow pregnant women receiving a dose of acellular pertussis vaccine for 4 weeks after vaccination. Design and settings A prospective observational study conducted in 2 New Zealand regions. Participants Women in their 28th–38th week of pregnancy, recruited from primary care and antenatal clinics at the time of Tdap administration. Telephone interviews were conducted at 48 h and 4 weeks postvaccination. Main outcomes measures Outcomes were injection site reactions, systemic symptoms and serious adverse events (SAEs). Where available, data have been classified and reported according to Brighton Collaboration definitions. Results 793 women participated with 27.9% receiving trivalent inactivated influenza vaccine concomitantly. 79% of participants reported mild or moderate pain and 2.6% severe pain. Any swelling was reported by 7.6%, induration by 12.0% (collected from 1 site only, n=326), and erythema by 5.8% of participants. Fever was reported by 17 (2.1%) participants, 14 of these occurred within 24 h. Headache, dizziness, nausea, myalgia or arthralgia was reported by <4% of participants, respectively, and fatigue by 8.4%. During the study period, there were 115 adverse events in 113 participants, most of which were minor. At the end of the reporting period, 31 events were classified as serious (eg, obstetric bleeding, hypertension, infection, tachycardia, preterm labour, exacerbation of pre-existing condition and pre-eclampsia). All had variable onset time from vaccination. There were two perinatal deaths. Clinician assessment of all SAEs found none likely to be vaccine related. Conclusions Vaccination with Tdap in pregnant women was well tolerated with no SAE likely to be caused by the vaccine. Trial registration number ACTRN12613001045707.

Febrile events including convulsions following the administration of four brands of 2010 and 2011 inactivated seasonal influenza vaccine in NZ infants and children: The importance of routine active safety surveillance

OBJECTIVE To evaluate and compare rates of febrile events, including febrile convulsion, following immunisation with four brands of inactivated 2010 and 2011 influenza vaccine in NZ infants and children. DESIGN Retrospective telephone surveys of parents of infants and children who received at least one dose of the vaccines of interest. SETTING 184 NZ General Practices who received the vaccines of interest. PARTICIPANTS Recipients of 4088 doses of trivalent inactivated vaccines Fluvax(®), Vaxigrip(®), Influvac(®) and Fluarix(®) and/or monovalent Celvapan. Vaccinees were identified via the electronic Practice Management System and contacted consecutively. MAIN OUTCOME MEASURES Primary outcome was febrile convulsive seizure. Secondary outcomes were presence of fever plus other organ system specific symptoms. RESULTS The parental response rate was 99%. Of 4088 doses given, 865 were Fluvax(®), 2571 Vaxigrip(®), 204 Influvac(®), 438 Fluarix(®) and 10 Celvapan. Three febrile convulsions followed Fluvax(®), a rate of 35 per 10,000 doses. No convulsions occurred following any dose of the other vaccines. There were nine febrile events that included rigors, all following Fluvax(®). Fever occurred significantly more frequently following administration of Fluvax(®) compared with the other brands of vaccines (p<0.0001) and Fluvax recipients were more likely to seek medical attention. Influvac(®) also had higher rates of febrile reactions (OR 0.54, 0.36-0.81) than the other two brands Vaxigrip(®) (OR 0.21, 0.16-0.27) and Fluarix(®) (OR 0.10, 0.05-0.20). After multivariable analysis vaccine, European ethnicity and second dose of vaccine were significantly associated with reporting of fever within 24h of vaccination. CONCLUSIONS Influenza vaccines have different rates of reactogenicity in children which varies between ethnic groups. High rates of febrile convulsions and reactions in children receiving Fluvax(®) and to a lesser extent the higher fever rates in those receiving Influvac(®) compared with the other two brands of influenza vaccines in this study suggests that reactogenicity profiles need to be considered prior to national policy advice each season. The risk-benefit profile in children might not be equally favourable for all licensed paediatric influenza vaccines. More attention needs to be given to comparative research for all trivalent seasonal vaccines, and with all strain changes.

Determining immunisation coverage rates in primary health care practices: a simple goal but a complex task.

PURPOSE To explore the quality of data recording by practices and identify issues to be considered and addressed before such data can be used as a continuous measure of immunisation delivery. METHODS One hundred and twenty-four randomly selected general practices visited to measure immunisation coverage using the various practice management systems (PMS) in use. To capture all target children it was necessary to build two queries: one generated a list of all children aged between 6 weeks and 2 years who had been to the practice, regardless of enrollment status; the other asked dates and nature of all immunisations given. Each different PMS required a unique query to extract the necessary information. RESULTS Variability encountered included different types and versions of PMS and operating systems; variable degree of staff technical competence with their PMS; proportion of enrolled children ranging from nearly 0 to 100%; lack of consistency of the nature and location of data entry and coding; and unreliability of dates relating to some vaccination events. RECOMMENDATIONS To improve recording of immunisation coverage we recommend a standard early age of registration and enrollment; standard definitions of the denominator and of immunisation delay; greater uniformity of PMS; improved staff training; intrinsic data quality checks; integration of PMS with changes in the immunisation schedule; incentives and interval electronic checks to improve data quality.

MeNZB™ vaccine and epidemic control : When do you stop vaccinating?

New Zealand developed a strain-specific group B meningococcal vaccine to control an epidemic. Following a mass vaccination campaign of three doses to the population under 20 years of age, commencing in July 2004, the vaccine continued to be offered routinely as a four-dose schedule from 6 weeks of age. There is little international data on when to cease epidemic vaccination campaigns. The decision to stop using this vaccine needed to take into account a range of factors. These included epidemiology, vaccine effectiveness and duration of immunity, vaccine coverage, concomitant use with other vaccinations being added to the infant schedule, vaccine supply and cost-benefit criteria. This paper discusses these issues, along with the potential challenges for communication to both health professionals and the public.

Fever following administration of two inactivated influenza vaccines--a survey of parents of New Zealand infants and children 5 years of age and under.

UNLABELLED Due to a dramatic increase in reported febrile convulsions in Western Australia following a routine pediatric influenza vaccination programme we evaluated parental recall of fever in their child following 2010 trivalent influenza vaccine manufactured by either Sanofi Pasteur (Vaxigrip(®)) or CSL Biotherapies (Fluvax(®)) to determine if the rates of febrile events in infants and children 5 years and under following administration of either Vaxigrip(®) or Fluvax(®) were significantly different. METHOD A convenience sample of New Zealand General practices who had received stocks of the vaccines of interest consecutively contacted parents of infants and children under 5 years of age who received at least one dose of 2010 influenza vaccine. A brief questionnaire was administered with the main outcome parental recall of fever within 24 h of vaccination. RESULTS Response rate was 99%. There were 327 parents of children aged 6 months to 5 years attending one of 23 primary care practices who had received a dose of either the Vaxigrip(®) or Fluvax(®) vaccine between 4th March and 28th June 2010 surveyed. A total of 422 doses were given of which 267 were Vaxigrip(®), 133 were Fluvax(®) and 22 another vaccine. Fever occurred significantly more frequently within 24 h following administration of Fluvax(®) compared with Vaxigrip(®) RR 4.33 (2.44-7.70). When fevers were measured they were, on average, higher in the Fluvax(®) vaccines (38°C compared with 39°C). Additionally, recipients were more likely to seek medical advice for fever following Fluvax(®) RR 23.11 (2.96-180.12). CONCLUSIONS There is considerable variation in reactogenicity between two 2010 seasonal vaccines in infants and young children. Vaxigrip(®) is significantly less reactogenic when compared to Fluvax(®) in this population in which Fluvax(®) is associated with unacceptably high rates of febrile reactions. There has been insufficient safety evaluation of seasonal influenza vaccine safety in this population.