Why are some outbreaks worse than others? COVID-19 outbreak management strategies from a PHU perspective.

BACKGROUND: From a Public Health Unit (PHU) perspective, this review aimed to examine factors associated with adverse outbreak outcomes, to identify evidence based focal strategies of managing COVID-19 outbreaks in aged care settings. METHODS: A retrospective review of PHU documentation examined all 55 COVID-19 outbreaks in Wide Bay RACFs across the first 3 COVID-19 waves in Queensland, through thematic and statistical analysis. ​. RESULTS: Thematic analysis using the framework approach identified 5 themes associated with outcomes of COVID-19 outbreaks in RACFs. These were analysed for statistical significance against outbreak outcomes including duration, attack rate and case fatality rate. There was a significant relationship between memory support unit (MSU) involvement and adverse outbreak outcomes. Attack rate was significantly associated with communication frequency, symptom monitoring and case detection approach, staff shortages and cohorting. Staff shortages were also significantly associated with a prolonged outbreak duration. There was no statistically significant relationship between outbreak outcomes and resource availability or infection control strategy. ​. CONCLUSIONS: This emphasises the importance of frequent communication between PHUs and RACFs during active outbreaks, as well as the need for regular symptom monitoring and prompt case detection, to minimise viral transmission. Staff shortages and cohorting are also crucial factors to be addressed during outbreak management. IMPLICATIONS FOR PUBLIC HEALTH: This review adds to the evidence basis of COVID-19 outbreak management strategies to improve PHU advice to RACFs, to mitigate viral transmission and ultimately reduce the burden of disease associated with COVID-19 and other communicable diseases.

Effect of infection control education program on childcare educator knowledge and confidence.

ISSUE ADDRESSED: Childcare educator knowledge gaps in infection control practices and outbreak management. This can contribute to the well-reported issue of transmission of infectious diseases in childcare centres and the associated health and economic costs. METHODS: A health promotion program in the form of an educational slideshow presentation with interactive question/answer component was developed and offered to all childcare centre staff in the Wide Bay region, Queensland. RESULTS: Childcare educators who participated in the education sessions reported a significant increase in their knowledge and confidence in outbreak management on pre- and post-intervention self-assessment. CONCLUSIONS: Simple educational programs can significantly improve the self-assessed knowledge and confidence of childcare educators in managing infectious diseases. SO WHAT?: Improving knowledge and confidence of childcare centre staff in managing basic infectious diseases can help reduce the health and economic impacts of these infections. Simple educational health promotion programs could be introduced as part of an orientation program for new staff, or refreshers for existing staff.

The role of human papillomavirus in head and neck squamous cell carcinoma: A case control study on a southern Chinese population.

HPV plays a role in the development of a portion of head and neck squamous cell carcinoma (HNSCC), but only limited information on its role in southern Chinese population is available. A multicenter case-control study was conducted. HPV type, viral integration, E6/7 mRNA expression status, and TP53 mutation were determined. A total of 228 HNSCC were recruited including 137 (60.1%) oral SCC, 34 (14.9%) oropharyngeal SCC, 31 (13.6%) laryngeal SCC, 21 (9.2%) hypopharyngeal SCC, and 5 (2.2%) lip and paranasal sinus SCC. High-risk HPV infection was found in 7.5% (17/228) of HNSCC, but only a small proportion of samples had evidence of viral integration (5.3%, 12/228) or E6/7 mRNA expression (4.4%, 10/228). HPV infection with oncogenic phenotype (integration and E6/7 mRNA expression) was significantly more common in oropharyngeal SCC than controls (9/34, 26.5% vs. 0/42, 0.0%, P < 0.001). Smoking showed a significant association with HNSCC, oropharyngeal SCC, and laryngeal SCC. TP53 mutation was associated with HNSCC (P < 0.001). Older age, TP53 mutation, and HPV16 infection with oncogenic phenotypes were independently associated factors for HNSCC with odds ratios of 1.03 (1.02-1.05), 3.38 (1.71-6.66), and 9.19 (1.13-74.68), respectively. High-risk HPV infection of head and neck mucosa is not uncommon in the Hong Kong population. This study found that 26-30% of oropharyngeal carcinoma was associated with HPV infection, mostly HPV16, and that smoking which predisposes to TP53 mutations was another important risk factor.

Effect of facemasks on empathy and relational continuity: a randomised controlled trial in primary care.

BACKGROUND: There is limited evidence to support the use of facemasks in preventing infection for primary care professionals. Negative effects on communication has been suggested when the physician wears a facemask. As communication skills and doctor patient relationship are essential to primary care consultations, the effects of doctor's facemask wearing were explored. METHOD: A randomised controlled study was conducted in primary care to explore the effects of doctors wearing facemasks on patients' perception of doctors' empathy, patient enablement and patient satisfaction. Primary care doctors were randomized to mask wearing and non mask wearing clinical consultations in public primary care clinics in Hong Kong. Patients' views were gathered using the Consultation and Relational Empathy (CARE) Measure, Patient Enablement Instrument (PEI) and an overall satisfaction rating scale. The effects of face mask wearing were investigated using multilevel (hierarchical) modelling. RESULTS: 1,030 patients were randomised to doctor-mask wearing consultations (n = 514) and non mask wearing consultations (n = 516). A significant and negative effect was found in the patients' perception of the doctors' empathy (CARE score reduction -0.98, p-value = 0.04). In the more established doctor-patient relationship, the effect of doctors' mask wearing was more pronounced (CARE score reduction -5.67, p-value = 0.03). CONCLUSION: This study demonstrates that when doctors wearing a facemask during consultations, this has a significant negative impact on the patient's perceived empathy and diminish the positive effects of relational continuity. Consideration should be taken in planning appropriate use of facemasks in infectious disease policy for primary care and other healthcare professionals at a national, local or practice level. CLINICAL TRIAL REGISTRATION: This trial was registered on Chinese Clinical Trial Register (ChiCTR). Registration no.: ChiCTR-TTRCC-12002519. URL: http://www.chictr.org/en/proj/show.aspx?proj=3486. Due to administrative error, registration of trial did not take place until after the trial started on 1st August 2011 and registration number was released on 21st September 2012.

Evolving epidemiology of Q fever in Wide Bay.

Abstract: Q fever is a notifiable disease in Australia due to its public health significance. Recent data in the Wide Bay region (Queensland, Australia) suggests a rising number and changing geographical distribution of Q fever cases. This study aims to evaluate these changes through analysis of data from Queensland Health's Notifiable Conditions System (NoCS) over a ten-year period. A comparison was made between the recent five-year period (2018-2022) and the preceding five-year period (2013-2017) with reference to incidence rates, location of cases and likely exposures. Incidence rates of Q fever showed an upward trend over time, particularly in urban areas. This highlights the need for increased clinical suspicion, improved awareness among the community and healthcare providers, and potentially broadening of vaccination recommendations in the future.

Willingness to accept H1N1 pandemic influenza vaccine: a cross-sectional study of Hong Kong community nurses.

BACKGROUND: The 2009 pandemic of influenza A (H1N1) infection has alerted many governments to make preparedness plan to control the spread of influenza A (H1N1) infection. Vaccination for influenza is one of the most important primary preventative measures to reduce the disease burden. Our study aims to assess the willingness of nurses who work for the community nursing service (CNS) in Hong Kong on their acceptance of influenza A (H1N1) influenza vaccination. METHODS: 401 questionnaires were posted from June 24, 2009 to June 30, 2009 to community nurses with 67% response rate. Results of the 267 respondents on their willingness to accept influenza A (H1N1) vaccine were analyzed. RESULTS: Twenty-seven percent of respondents were willing to accept influenza vaccination if vaccines were available. Having been vaccinated for seasonable influenza in the previous 12 months were significantly independently associated with their willingness to accept influenza A (H1N1) vaccination (OR = 4.03; 95% CI: 2.03-7.98). CONCLUSIONS: Similar to previous findings conducted in hospital healthcare workers and nurses, we confirmed that the willingness of community nurses to accept influenza A (H1N1) vaccination is low. Future studies that evaluate interventions to address nurses' specific concerns or interventions that aim to raise the awareness among nurses on the importance of influenza A (H1N1) vaccination to protect vulnerable patient populations is needed.

Epidemiologic risk profile of infection with different groups of human papillomaviruses.

This study identified the age-specific prevalence and epidemiologic risk profile for infection with different groups and species of human papillomaviruses (HPV). Structured interview and HPV testing were conducted for 2,604 Chinese women self-referred for cervical screening. Independent risk factors for infection were identified by multiple logistic regressions. Overall, a major peak of HPV infection was observed at women aged 26-30 years, and a minor peak at 46-55 years. This pattern was observed for high-risk, low-risk, and alpha-5/7/9 HPVs; but alpha-3/6 HPVs showed peaks of similar magnitudes in young and older women. Independent risk factors for HPV infection (all types combined) included younger age (OR [95% CI] for >55 vs. < or =30 years = 0.22 [0.09-0.55]; 31-45 vs. < or = 30 years = 0.57 [0.33-0.99]), having > or =4 lifetime sexual partners (2.28 [1.06-4.88]), and smoking (2.24 [1.22-4.10]). Young age and smoking were the most consistent independent risk factors observed across different HPV groups. The risk profile for high-risk HPV was similar to alpha-5/7/9. Single-type infection was associated with having more sexual partners, higher education level and oral contraception; whereas multiple-type infection was associated with smoking. In conclusion, a U-shaped age-specific prevalence curve was observed for HPV infection overall, but with a different pattern for different HPV species. Different HPV groups showed variations in their risk profiles. These data are useful for formulating preventative strategy for HPV-related diseases. Catch-up vaccination program in Hong Kong should cover a wider age group as the first peak of infection occurred relatively late.

Stephania tetrandra prevents and regresses liver fibrosis induced by carbon tetrachloride in rats.

BACKGROUND AND AIM: There is currently no safe and effective treatment for liver fibrosis. We have previously shown that Stephania tetrandra (ST) and Salvia miltiorrhiza (SM) suppress cell proliferation and enhance apoptosis of hepatic stellate cell (HSC) in vitro. In this study, we aimed to investigate the anti-fibrotic effect of these two herbs in vivo. METHODS: Liver fibrosis was induced by carbon tetrachloride (CCl(4)) injection in rats for 5 weeks. SM, ST or SM + ST was gavaged on day 1 of CCl(4) administration to study the preventive effects of herbs on hepatic fibrosis. In a separate study designed to assess possible fibrosis regression, rats were randomly allocated to be treated with SM, ST or SM + ST when fibrosis was established. Liver injury and collagen content were assessed. HSC activation and apoptosis were determined. RESULTS: As compared with the CCL(4)-only rats, serum ALT was significantly lower in CCl(4)-treated rats that received either SM (P < 0.01) or ST (P < 0.01). Administration of ST significantly prevented (P < 0.01) or reversed the hepatic fibrosis (P < 0.01) induced by CCL(4). Moreover, rats treated with ST had reduced protein expression of alpha-SMA both in prevention (P < 0.05) and in regression (P < 0.01) experiments. The double-color staining of alpha-SMA and TUNEL showed that ST increased HSC apoptosis. However, co-treatment of SM + ST did not increase the antifibrotic effect of ST. CONCLUSIONS: Stephania tetrandra safely and effectively prevents and reverses hepatic fibrosis through activating HSC apoptosis in rats.

Can Human Papillomavirus DNA Self-sampling be an Acceptable and Reliable Option for Cervical Cancer Screening in Female Sex Workers?

BACKGROUND: The causal relation between human papillomavirus (HPV) and cervical cancer has enabled HPV self-sampling to be envisaged as a possible screening method. OBJECTIVES: The aim of this study is to explore the acceptability and reliability of HPV DNA self-sampling as an alternative option for cervical screening among female sex workers. METHODS: Sixty-eight participants carried out self-sampling for HPV testing, gave a clinician-obtained sample for HPV testing, and a Papanicolaou test. After the samplings, the participants were questioned on the acceptability of the tests. RESULTS: Most participants (65.6%) preferred to adopt HPV DNA self-sampling in the future; in particular, those without previous experience of Papanicolaou tests marginally significantly preferred self-sampling (86.7%, P = .055). The overall crude agreement in HPV detection rates between clinician and HPV DNA self-sampling was 85.3% (58/68), with a κ of 0.69 (95% confidence interval, 0.51-0.87). The sensitivity and specificity of self-collected samples were 66.7% and 66.1%, respectively, and the positive and negative predicted values were 24.0% and 92.5%, respectively. The prevalence of HPV was slightly higher in self-collected samples (39.7%, 27/68) than in clinician-collected samples (36.8%, 25/68). The participants expressed positive attitudes toward self-sampling but were less confident in their skills of self-sampling compared with clinicians (70.6% versus 91.2%). CONCLUSIONS: The findings showed that self-sampling could be incorporated into current cervical cancer screening approaches. IMPLICATIONS FOR PRACTICE: Self-sampling could potentially increase compliance to cervical cancer screening and thus reduce the morbidity and mortality from cervical cancer. Further research and education on self-sampling will be required for women of diverse backgrounds.

Evaluation of the Impact of Human Papillomavirus DNA Self-sampling on the Uptake of Cervical Cancer Screening.

BACKGROUND: The rate of uptake of the Papanicolaou (Pap) smear is generally low. Its causal relationship with human papillomavirus (HPV) DNA allows HPV DNA self-sampling to be used as an alternative screening tool for cervical cancer. OBJECTIVES: This study explored the acceptability of HPV DNA self-sampling and its impact on the rate of compliance with cervical cancer screening. METHODS: A crossover randomized clinical trial was conducted in community-based clinics. Participants were allocated to 1 of the following 2 arms: arm 1: self-sampling before a Pap smear; and arm 2: a Pap smear before self-sampling. After completing the 2 screening methods, participants in each arm took part in face-to-face interviews using standardized, structured questionnaire. RESULTS: The participants accepted both self-sampling (7.7/10) and a Pap smear (7.8/10) for cervical cancer screening. However, participants without previous experience of Pap smears or who had more than 2 sexual partners preferred self-sampling (P < .05). The participants expressed overall positive feelings toward self-sampling, and there was good agreement in HPV detection between the 2 screening methods (κ = 0.65). We estimate that the introduction of HPV DNA self-sampling could increase the future rate of uptake of cervical cancer screening by 6.5% and would entail lower costs. CONCLUSION: Human papillomavirus DNA self-sampling could be an alternative screening method to increase the coverage of cervical cancer screening. IMPLICATIONS FOR PRACTICE: Human papillomavirus DNA self-sampling could overcome the barriers raised by Pap smears and enhance the coverage of cervical cancer screening. Promotional publicity and education are essential.

Socioeconomic disparity in breast cancer detection in Hong Kong--a high income city: retrospective epidemiological study using the Breast Cancer Registry.

BACKGROUND: It is not known whether socioeconomic disparities affect the detection of breast cancer in Asian countries where the incidence of breast cancer is a rising trend. In this study, we explore the socioeconomic profiles of women and the stage of the disease at the time of diagnosis in breast cancer patients aged 40 or over in Hong Kong. METHOD: During the period 2008 to 2011, 5393 breast cancer patients registered with the Hong Kong Breast Cancer Registry. Participants and their clinicians were asked to complete standardised questionnaires including patient socio-demographics, health history and risk factors, the course of the disease, post-treatment physical discomfort and psychosocial impact, follow-up recurrence and survival status. RESULTS: Monthly household incomes, educational levels and the practice of regular screening are independently associated with the stage of the disease at diagnosis. Higher socioeconomic status and a higher educational level were associated with an earlier stage of the disease at the time of diagnosis. Yearly clinical examinations, ultrasound and mammographic screening every 2 to 3 years were significantly associated with the earlier detection of breast cancer. CONCLUSION: There were socioeconomic disparities among Hong Kong women who were found to have breast cancer. Population-based screening policies, including raising awareness among women at risk, should be implemented.

Meta-analysis on prevalence and attribution of human papillomavirus types 52 and 58 in cervical neoplasia worldwide.

OBJECTIVE: To estimate the prevalence and attribution of two non-vaccine-covered HPV types (HPV52 and HPV58) across the world. METHODS: Meta-analysis on studies reported in English and Chinese between 1994 and 2012. RESULTS: The pooled prevalence and attribution rates of HPV52 and HPV58 in invasive cervical cancers were significantly higher in Eastern Asia compared to other regions (HPV52 prevalence: 5.7% vs. 1.8-3.6%, P<0.001; HPV52 attribution: 3.7% vs. 0.2-2.0%; HPV58 prevalence: 9.8% vs. 1.1-2.5%, P<0.001; HPV58 attribution: 6.4% vs. 0.7-2.2%, P<0.001). Oceania has an insufficient number of studies to ascertain the prevalence of HPV52. Within Eastern Asia, the attribution of HPV58 to invasive cervical cancer was 1.8-fold higher than that of HPV52. Similarly, HPV52 and HPV58 shared a higher prevalence and attribution among cervical intraepithelial neoplasia in Eastern Asia. In contrast to the classical high-risk type, HPV16, the prevalence and attribution of HPV52 and HPV58 decreased with increasing lesion severity. Thus, HPV52 and HPV58 behave as an "intermediate-risk" type. CONCLUSION: The attribution of HPV52 and HPV58 to cervical intraepithelial neoplasia and invasive cancer in Eastern Asia were respectively 2.5-2.8 and 3.7-4.9 folds higher than elsewhere. Changes in the attributed disease fraction can serve as a surrogate marker for cross-protection or type replacement following widespread use of HPV16/18-based vaccines. This unique epidemiology should be considered when designing HPV screening assays and vaccines for Eastern Asia.

Risk factors and natural history of breast cancer in younger Chinese women.

AIM: To investigate the age differences in the risk factors, clinicopathological characteristics and patterns of treatment of female breast cancer patients. METHODS: Seven thousand one hundred and fifty-two women with primary breast cancer from the Hong Kong Breast Cancer Registry were recruited after receiving patients' consent, they were asked to complete standardized questionnaires which captured their sociodemographic characteristics and risk factors associated with breast cancer development. Among them, clinicopathological data and patterns of treatment were further collected from medical records of 5523 patients with invasive breast cancers. Patients were divided into two groups according to the age at diagnosis: younger (< 40 years old) vs older patients (≥ 40 years old) for subsequent analyses. RESULTS: Analysis on the sociodemographic characteristics and exposure to risk factors were performed on 7152 women with primary breast cancer and the results revealed that younger patients were more likely to have unhealthy lifestyles; these include a lack of exercise (85.4% vs 73.2%, P < 0.001), having high stress in life (46.1% vs 35.5%, P < 0.001), having dairy/meat-rich diets (20.2% vs 12.9%, P < 0.001), having alcohol drinking habit (7.7% vs 5.2%, P = 0.002). Younger patients were also more likely to have hormone-related risk factors including nulliparity (43.3% vs 17.8%, P < 0.001) and an early age at menarche (20.7% vs 13.2%, P < 0.001). Analyses on clinicopathological characteristics and patterns of treatment were performed on 5523 women diagnosed with invasive breast cancer. The invasive tumours in younger patients showed more aggressive pathological features such as having a higher percentage of grade 3 histology (45.7% vs 36.5%, P < 0.001), having a higher proportion of tumours with lymphovascular invasion (39.6% vs 33.2%, P = 0.003), and having multifocal disease (15.7% vs 10.3%, P < 0.001); they received different patterns of treatment than their older counterparts. CONCLUSION: Younger patients in Hong Kong are more likely to encounter risk factors associated with breast cancer development and have more aggressive tumours than their older counterparts.

Knowledge, attitude, practice and barriers on vaccination against human papillomavirus infection: a cross-sectional study among primary care physicians in Hong Kong.

This study explored the knowledge, attitude, practice and barriers to prescribe human papillomavirus (HPV) vaccines among private primary care physicians in Hong Kong. A self-administered questionnaire survey was conducted by sending letters to doctors who had joined a vaccination program for school girls. From 720 surveys sent, 444 (61.7%) completed questionnaires were returned and analyzed. For knowledge, few responded to questions accurately on the prevalence of cervical HPV (27.9%) and genital wart infection (13.1%) among sexually active young women in Hong Kong, and only 44.4% correctly answered the percentage of cervical cancers caused by HPV. For attitude, most agreed that HPV vaccination should be fully paid by the Government (68.3%) as an important public health strategy. Vaccination against HPV was perceived as more important than those for genital herpes (52.2%) and Chlamydia (50.1%) for adolescent health, and the majority selected adolescents aged 12-14 years as the ideal group for vaccination. Gardasil(®) (30.9%) and Cervarix(®) (28.0%) were almost equally preferred. For practice, the factors influencing the choice of vaccine included strength of vaccine protection (61.1%), long-lasting immunity (56.8%) and good antibody response (55.6%). The most significant barriers to prescribe HPV vaccines consisted of parental refusal due to safety concerns (48.2%), and their practice of advising vaccination was mostly affected by local Governmental recommendations (78.7%). A substantial proportion of physicians had recommended HPV vaccines for their female clients/patients aged 18-26 years for protection of cervical cancer (83.8%) or both cervical cancer and genital warts (85.5%). The knowledge on HPV infection was low among physicians in Hong Kong. Prescription of HPV vaccine was hindered by the perceived parental concerns and was mostly relied on Governmental recommendations. Educational initiatives should be targeted towards both physicians and parents, and the Government should consider full subsidy to enhance vaccine uptake rate.

Seasonal influenza vaccination predicts pandemic H1N1 vaccination uptake among healthcare workers in three countries.

The aim of this study was to identify the common barriers and facilitators for acceptance of pandemic influenza vaccination across different countries. This study utilized a standardized, anonymous, self-completed questionnaire-based survey recording the demographics and professional practice, previous experience and perceived risk and severity of influenza, infection control practices, information of H1N1 vaccination, acceptance of the H1N1 vaccination and reasons of their choices and opinions on mandatory vaccination. Hospital-based doctors, nurses and allied healthcare workers in Hong Kong (HK), Singapore (SG) and Leicester, United Kingdom (UK) were recruited. A total of 6318 (HK: 5743, SG: 300, UK: 275) questionnaires were distributed, with response rates of 27.1% (HK), 94.7% (SG) and 94.5% (UK). The uptake rates for monovalent 2009 pandemic H1N1 vaccine were 13.5% (HK), 36.2% (SG) and 41.3% (UK). The single common factor associated with vaccine acceptance across all sites was having seasonal influenza vaccination in 2009. In UK and HK, overestimation of side effect reduced vaccination acceptance; and fear of side effect was a significant barrier in all sites. In HK, healthcare workers with more patient contact were more reluctant to accept vaccination. Drivers for vaccination in UK and HK were concern about catching the infection and following advice from health authority. Only a small proportion of respondents agreed with mandatory pandemic influenza vaccination (HK: 25% and UK: 42%), except in Singapore where 75.3% were in agreement. Few respondents (<5%) chose scientific publications as their primary source of information, but this group was more likely to receive vaccination. The acceptance of pandemic vaccine among healthcare workers was poor (13-41% of respondents). Breaking barriers to accept seasonal influenza vaccination should be part of the influenza pandemic preparedness plan. Mandatory vaccination even during pandemic is likely to arouse substantial discontent.

Willingness of Hong Kong healthcare workers to accept pre-pandemic influenza vaccination at different WHO alert levels: two questionnaire surveys.

OBJECTIVE: To assess the acceptability of pre-pandemic influenza vaccination among healthcare workers in public hospitals in Hong Kong and the effect of escalation in the World Health Organization's alert level for an influenza pandemic. DESIGN: Repeated cross sectional studies using self administered, anonymous questionnaires SETTING: Surveys at 31 hospital departments of internal medicine, paediatrics, and emergency medicine under the Hong Kong Hospital Authority from January to March 2009 and in May 2009 PARTICIPANTS: 2255 healthcare workers completed the questionnaires in the two studies. They were doctors, nurses, or allied health professionals working in the public hospital system. MAIN OUTCOME MEASURES: Stated willingness to accept pre-pandemic influenza vaccination (influenza A subtypes H5N1 or H1N1) and its associating factors. RESULTS: The overall willingness to accept pre-pandemic H5N1 vaccine was only 28.4% in the first survey, conducted at WHO influenza pandemic alert phase 3. No significant changes in the level of willingness to accept pre-pandemic H5N1 vaccine were observed despite the escalation to alert phase 5. The willingness to accept pre-pandemic H1N1 vaccine was 47.9% among healthcare workers when the WHO alert level was at phase 5. The most common reasons for an intention to accept were "wish to be protected" and "following health authority's advice." The major barriers identified were fear of side effects and doubts about efficacy. More than half of the respondents thought nurses should be the first priority group to receive the vaccines. The strongest positive associating factors were history of seasonal influenza vaccination and perceived risk of contracting the infection. CONCLUSIONS: The willingness to accept pre-pandemic influenza vaccination was low, and no significant effect was observed with the change in WHO alert level. Further studies are required to elucidate the root cause of the low intention to accept pre-pandemic vaccination.