Annette K. Regan

Antenatal care provider's advice is the key determinant of influenza vaccination uptake in pregnant women

Although influenza vaccination is an important component of antenatal care and is recommended and funded by the Australian government, vaccination uptake has been low.

Using automated text messages to monitor adverse events following immunisation in general practice

Objective: To assess the performance of SmartVax, a prototypic active monitoring system for adverse events following immunisation (AEFI) using short message service (SMS) text messages and clinical data extracted from commercially available medical practice management software.

Influenza vaccine effectiveness estimates for Western Australia during a period of vaccine and virus strain stability, 2010 to 2012.

During 2010-2012 the strain composition of the influenza vaccine in the Southern Hemisphere did not change, but the circulating virus type/subtype did. We pooled data for these years from the Western Australian sentinel medical practice surveillance system for influenza to estimate vaccine effectiveness (VE) by influenza virus type and subtype. A case test-negative design was used with VE estimated as (1-odds ratio)×100%. There were 2182 patients included in the analysis across the 3 years studied. The predominant subtype was A/H1pdm09 in 2010 and 2011, and A/H3 in 2012. The overall adjusted VE estimate against all influenza for 2010-2012 was 51% (95% CI: 36, 63). Estimates were highest against A/H1pdm09 at 74% (95% CI: 47, 87), followed by 56% (95% CI: 33, 71) for influenza B and lowest against A/H3 at 39% (95% CI: 13, 57). When analyses were restricted to compare influenza-positive patients with patients who tested positive for a non-influenza virus, overall adjusted VE was 59% (95% CI: 39, 72). These results suggest moderate protection against influenza by vaccination in Western Australia over the period 2010-2012, and are consistent with findings from other settings.

The impact of pandemic A(H1N1)pdm09 influenza and vaccine-associated adverse events on parental attitudes and influenza vaccine uptake in young children.

INTRODUCTION Parental attitudes towards vaccination significantly influence vaccine uptake. The A(H1N1)pdm09 influenza pandemic was followed in 2010 by an unprecedented increase in febrile reactions in children receiving trivalent inactivated influenza vaccine manufactured by bioCSL. Uptake of TIV in children <5 years in Western Australia (WA) decreased in 2010 and has remained low. The impact of pandemic A(H1N1)pdm09 and adverse-events on parental attitudes towards vaccination is uncertain. MATERIALS AND METHODS A parental attitudes survey towards influenza illness and vaccination was conducted as part of the West Australian Influenza Vaccine Effectiveness study. Vaccination status was assessed by parental interview and confirmed by the national register and/or vaccine providers. Parental attitudes from vaccinated and unvaccinated children and attitudes in 2008-2009 and 2010-2012 were compared. Principal Component Analysis was conducted to determine core attitudes that influenced vaccine uptake. RESULTS Vaccination history and parental attitude surveys were available from 2576 children. Parents of fully vaccinated children less frequently stated that influenza was a mild disease, more frequently stated that influenza vaccine was safe and were less frequently worried about vaccine side effects. Uptake of influenza vaccine decreased significantly from 2010 onwards. From 2010, parents were less concerned about severe influenza, but more concerned about vaccine side effects and safety. Despite this significant shift in attitudes towards influenza vaccine, parental acceptance of vaccines on the national immunisation program did not change. Principal Component Analysis revealed that attitudes around vaccine safety and efficacy were the most important attitudes impacting on vaccine uptake. CONCLUSIONS Parental attitudes to influenza vaccine changed from 2010. Confidence in the WA preschool influenza vaccination program remains low yet appeared unchanged for other vaccines. Restoring public confidence in childhood influenza vaccination is needed before uptake can be improved.

Trends in seasonal influenza vaccine uptake during pregnancy in Western Australia: Implications for midwives

BACKGROUND Antenatal influenza vaccination is an important public health intervention for preventing serious illness in mothers and newborns, yet uptake remains low. AIM To evaluate trends in seasonal influenza vaccine coverage and identify determinants for vaccination among pregnant women in Western Australia. METHODS We conducted an annual telephone survey in a random sample of post-partum women who delivered a baby in Western Australia between 2012 and 2014. Women were asked whether influenza vaccination was recommended and/or received during their most recent pregnancy; women were also asked why or why they were not immunised. FINDINGS Between 2012 and 2014, influenza vaccine coverage increased from 22.9% to 41.4%. Women who reported receiving the majority of their antenatal care from a private obstetrician were significantly more likely to have influenza vaccination recommended to them than those receiving the majority of their care from a public antenatal hospital or general practitioner (p<0.001). In 2014, the most common reason women reported for accepting influenza vaccination was to protect the baby (92.8%) and the most common reason for being unimmunised was lack of a healthcare provider recommendation (48.5%). DISCUSSION Antenatal influenza vaccination uptake is increasing, but coverage remains below 50%. A recommendation from the principal care provider is an important predictor of maternal influenza vaccination. CONCLUSION Antenatal care providers, including midwives, have a key role in providing appropriate information and evidence-based recommendations to pregnant women to ensure they are making informed decisions. Consistent recommendations from antenatal care providers are critical to improving influenza vaccine coverage in pregnant women.

A prospective cohort study assessing the reactogenicity of pertussis and influenza vaccines administered during pregnancy

BACKGROUND Pertussis vaccination during pregnancy can prevent 91% of infant infections. In 2015, antenatal pertussis vaccination programs were introduced across Australia. METHODS To monitor the safety of this program, pregnant women who received trivalent influenza vaccine (TIV) and/or diphtheria-tetanus-acellular pertussis vaccine (dTpa) were surveyed by text message seven days post-vaccination about possible adverse events following immunization (AEFI). Univariate logistic regression models were used to calculate the odds of reporting an AEFI following dTpa compared to TIV. Similar analyses were used to compare AEFI reported by women who received a previous dose of dTpa in 2011/2012 as part of a state-wide cocooning program. RESULTS Of 5155 women, 4347 (84.3%) replied; 10.8% indicated they experienced an AEFI. There was no difference in the proportion of women who reported any reaction by vaccine; however, women who received dTpa were more likely to report a local reaction than women who received TIV (7.1% and 3.2%, respectively; OR: 2.29; 95% CI: 1.61-3.26). There was evidence suggesting local reactions were more common among women with a previous dose of dTpa (11.4%) compared to women with no previous dose (6.0%; OR: 2.00; 95% CI: 0.95-4.25); 11 (0.3%) women reported attending a hospital emergency department. Subsequent follow-up indicated symptoms resolved and mother and infant were healthy. There was no difference in the proportion of women attending hospital by vaccine (p > 0.05). DISCUSSION Data on systemic and local reactions following receipt of TIV and dTpa during pregnancy support the safety of antenatal vaccination.

Effect of Maternal Influenza Vaccination on Hospitalization for Respiratory Infections in Newborns: A Retrospective Cohort Study.

Background: Infants are at increased risk of hospitalization for influenza. Although vaccinating women during pregnancy has been shown to reduce the incidence of influenza infection among newborns, population-based data are limited. Methods: A population-based cohort of 31,028 mothers and singleton infants were included in the analysis. Hospitalizations with a principal diagnosis or additional diagnoses consistent with severe respiratory illness occurring during the 2012 and 2013 southern hemisphere influenza seasons were identified using a state-wide hospital discharge database. Newborns were defined as “maternally vaccinated” if the mother received influenza vaccine ≥14 days before delivery. Cox regression models were used to estimate adjusted hazard ratios for hospitalization. Results: A total of 3169 infants were maternally vaccinated and 27,859 were unvaccinated; 732 hospitalizations were identified, 528 (69%) of which were for bronchiolitis. There were 21.9 hospitalizations per 100,000 person days among maternally vaccinated infants and 30.2 hospitalizations per 100,000 person days among unvaccinated infants. Maternally vaccinated infants were 25% less likely to be hospitalized for an acute respiratory illness during influenza season compared with unvaccinated infants (adjusted hazard ratio: 0.75, 95% confidence interval: 0.56–0.99, P = 0.04). Vaccinations administered in the third trimester were associated with a 33% reduction in the risk of newborn hospitalization (adjusted hazard ratio: 0.67, 95% confidence interval: 0.47–0.95, P = 0.03). No such reduction was identified for vaccinations administered earlier in pregnancy. Conclusions: Maternal influenza vaccination was associated with a reduction in the incidence of hospital admission for acute respiratory illness among infants <6 months of age. These data suggest that vaccination during third trimester may provide optimal benefit to the newborn.

A prospective cohort study comparing the reactogenicity of trivalent influenza vaccine in pregnant and non-pregnant women

BackgroundInfluenza vaccination during pregnancy can prevent serious illness in expectant mothers and provide protection to newborns; however, historically uptake has been limited due to a number of factors, including safety concerns. Symptomatic complaints are common during pregnancy and may be mistakenly associated with reactions to trivalent influenza vaccine (TIV). To investigate this, we compared post-vaccination events self-reported by pregnant women to events reported by non-pregnant women receiving TIV.MethodsA prospective cohort of 1,086 pregnant women and 314 non-pregnant female healthcare workers (HCWs) who received TIV between March-May 2014 were followed-up seven days post-vaccination to assess local and systemic adverse events following immunisation (AEFIs). Women were surveyed by text message regarding perceived reactions to TIV. Those reporting an AEFI completed an interview by telephone or mobile phone to ascertain details. Logistic regression models adjusting for age and residence were used to compare reactions reported by pregnant women and non-pregnant HCWs.ResultsSimilar proportions of pregnant women and non-pregnant, female HCWs reported ≥1 reaction following vaccination with TIV (13.0% and 17.3%, respectively; OR = 1.2 [95% CI: 0.8-1.8]). Non-pregnant, female HCWs were more likely to report fever or headache compared to pregnant women (OR: 4.6 [95% CI 2.1-10.3] and OR: 2.2 [95% CI 1.0-4.6], respectively). No other significant differences in reported symptoms were observed. No serious vaccine-associated adverse events were reported, and less than 2% of each group sought medical advice for a reaction.ConclusionsWe found no evidence suggesting pregnant women are more likely to report adverse events following influenza vaccination when compared to non-pregnant female HCWs of similar age, and in some cases, pregnant women reported significantly fewer adverse events. These results further support the safety of TIV administered in pregnant women.

Using SMS technology to verify the safety of seasonal trivalent influenza vaccine for pregnant women in real time

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Post-marketing surveillance of adverse events following immunization with inactivated quadrivalent and trivalent influenza vaccine in health care providers in Western Australia.

In 2015, inactivated quadrivalent influenza vaccine (QIV) was first introduced into the Australian market. A routine vaccine safety surveillance system in Western Australia was used to conduct post-licensure surveillance of adverse events following immunization with inactivated QIV and trivalent influenza vaccines (TIV) in a sample of 1685 healthcare providers (HCPs). A similar percentage of HCPs who received QIV reported having any reaction seven days post-vaccination as HCPs who received TIV (13.6 vs. 12.8%, respectively; p=0.66). However, a slightly higher percentage of HCPs who received QIV reported pain or swelling at the injection site as compared to HCPs who received TIV (6.9% vs. 4.2%, respectively; p=0.02). No serious vaccine-associated adverse events were detected during follow-up of either vaccine. Acknowledging the study limitations, the results of this post-marketing surveillance support the safety of QIV, suggesting there is little difference in the reactogenicity of QIV as compared to TIV.