Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
240
result(s) for
"MacIntyre, C. Raina"
Sort by:
Modelling of COVID-19 vaccination strategies and herd immunity, in scenarios of limited and full vaccine supply in NSW, Australia
2022
Several vaccines for SARS-CoV-2 are expected to be available in Australia in 2021. Initial supply is limited and will require a judicious vaccination strategy until supply is unrestricted. If vaccines have efficacy as post-exposure prophylaxis (PEP) in contacts, this provides more policy options. We used a deterministic mathematical model of epidemic response with limited supply (age-targeted or ring vaccination) and mass vaccination for the State of New South Wales (NSW) in Australia. For targeted vaccination, the effectiveness of vaccinating health workers, young people and older adults was compared. For mass vaccination, we tested varying vaccine efficacy (VE) and distribution capacities. With a limited vaccine stockpile enough for 1 million people in NSW, if there is efficacy as PEP, the most efficient way to control COVID-19 will be ring vaccination, however at least 90% of contacts per case needs to be traced and vaccinated. Health worker vaccination is required for health system resilience. Age based strategies with restricted doses make minimal impact on the epidemic, but vaccinating older people prevents more deaths. Herd immunity can only be achieved with mass vaccination. With 90% VE against all infection, herd immunity can be achieved by vaccinating 66% of the population. A vaccine with less than 70% VE cannot achieve herd immunity and will result in ongoing risk of outbreaks. For mass vaccination, distributing at least 60,000 doses per day is required to achieve control. Slower rates of vaccination will result in the population living with COVID-19 longer, and higher cases and deaths.
Journal Article
Trust in government, intention to vaccinate and COVID-19 vaccine hesitancy: A comparative survey of five large cities in the United States, United Kingdom, and Australia
2022
There is widespread hesitancy towards COVID-19 vaccines in the United States, United Kingdom, and Australia.
To identify predictors of willingness to vaccinate against COVID-19 in five cities with varying COVID-19 incidence in the US, UK, and Australia.
Online, cross-sectional survey of adults from Dynata’s research panel in July-September 2020.
Adults aged 18 and over in Sydney, Melbourne, London, New York City, or Phoenix.
Willingness to receive a COVID-19 vaccine; reason for vaccine intention.
To identify predictors of intention to receive a COVID-19 vaccine, we used Poisson regression with robust error estimation to produce prevalence ratios.
The proportion willing to receive a COVID-19 vaccine was 70% in London, 71% NYC, 72% in Sydney, 76% in Phoenix, and 78% in Melbourne. Age was the only sociodemographic characteristic that predicted willingness to receive a COVID-19 vaccine in all five cities. In Sydney and Melbourne, participants with high confidence in their current government had greater willingness to receive the vaccine (PR = 1.24; 95% CI = 1.07–1.44 and PR = 1.38; 95% CI = 1.74–1.62), while participants with high confidence in their current government in NYC and Phoenix were less likely to be willing to receive the vaccine (PR = 0.78; 95% CI = 0.72–0.85 and PR = 0.85; 95% CI = 0.76–0.96).
Consumer panels can be subject to bias and may not be representative of the general population.
Success for COVID-19 vaccination programs requires high levels of vaccine acceptance. Our data suggests more than 25% of adults may not be willing to receive a COVID-19 vaccine, but many of them were not explicitly anti-vaccination and thus may become more willing to vaccinate over time. Among the three countries surveyed, there appears to be cultural differences, political influences, and differing experiences with COVID-19 that may affect willingness to receive a COVID-19 vaccine.
Journal Article
Physical distancing, face masks, and eye protection for prevention of COVID-19
by
Wang, Quanyi
,
MacIntyre, C Raina
in
Betacoronavirus
,
Comment
,
Coronavirus Infections - epidemiology
2020
For eye protection, data are even less certain. [...]the systematic review and meta-analysis by Derek Chu and colleagues in The Lancet3 is an important milestone in our understanding of the use of personal protective equipment (PPE) and physical distancing for COVID-19. [...]this finding can inform lifting of societal restrictions and safer ways of gathering in the community. Masks worn within households in Beijing, China, prevented secondary transmission of SARS-CoV-2 if worn before symptom onset of the index case.15 Finally, Chu and colleagues reiterate that no one intervention is completely protective and that combinations of physical distancing, face mask use, and other interventions are needed to mitigate the COVID-19 pandemic until we have an effective vaccine. [...]randomised controlled trial data are available, this study provides the best specific evidence for COVID-19 prevention.
Journal Article
Reemergence of Human Monkeypox and Declining Population Immunity in the Context of Urbanization, Nigeria, 2017–2020
by
Ajisegiri, Whenayon Simeon
,
MacIntyre, C. Raina
,
Chughtai, Abrar A.
in
Analysis
,
Animals
,
Child
2021
A monkeypox outbreak in Nigeria during 2017-2020 provides an illustrative case study for emerging zoonoses. We built a statistical model to simulate declining immunity from monkeypox at 2 levels: At the individual level, we used a constant rate of decline in immunity of 1.29% per year as smallpox vaccination rates fell. At the population level, the cohort of vaccinated residents decreased over time because of deaths and births. By 2016, only 10.1% of the total population in Nigeria was vaccinated against smallpox; the serologic immunity level was 25.7% among vaccinated persons and 2.6% in the overall population. The substantial resurgence of monkeypox in Nigeria in 2017 appears to have been driven by a combination of population growth, accumulation of unvaccinated cohorts, and decline in smallpox vaccine immunity. The expanding unvaccinated population means that entire households, not just children, are now more susceptible to monkeypox, increasing risk of human-to-human transmission.
Journal Article
Non-pharmaceutical interventions during the roll out of covid-19 vaccines
2021
Yi Zhang and colleagues call for continued use of non-pharmaceutical interventions to control covid-19 during and after vaccine roll outs
Journal Article
Effectiveness of Cloth Masks for Protection Against Severe Acute Respiratory Syndrome Coronavirus 2
by
Macintyre, C. Raina
,
Chughtai, Abrar A.
,
Seale, Holly
in
2019 novel coronavirus disease
,
Betacoronavirus
,
coronavirus disease
2020
Cloth masks have been used in healthcare and community settings to protect the wearer from respiratory infections. The use of cloth masks during the coronavirus disease (COVID-19) pandemic is under debate. The filtration effectiveness of cloth masks is generally lower than that of medical masks and respirators; however, cloth masks may provide some protection if well designed and used correctly. Multilayer cloth masks, designed to fit around the face and made of water-resistant fabric with a high number of threads and finer weave, may provide reasonable protection. Until a cloth mask design is proven to be equally effective as a medical or N95 mask, wearing cloth masks should not be mandated for healthcare workers. In community settings, however, cloth masks may be used to prevent community spread of infections by sick or asymptomatically infected persons, and the public should be educated about their correct use.
Journal Article
Predictors of herpes zoster vaccination among Australian adults aged 65 and over
by
MacIntyre, C. Raina
,
Ricks, Thomas
,
Trent, Mallory J.
in
Adult
,
Adults
,
Allergy and Immunology
2022
To estimate HZ vaccine coverage in Australia among older Australians and to identify potential barriers to vaccination.
Analysis of data from three cross-sectional surveys administered online between 2019 and 2020.
Adults aged 65 and over residing in Australia.
Self-reported herpes zoster vaccination.
Among the 744 adults aged 65 and over in this sample, 32% reported being vaccinated for HZ, including 23% of participants aged 65–74, 55% of participants aged 75–84, and 0% for participants aged 85 and above. Those who are vaccinated with other immunisations are more likely to have received HZ vaccine, including seasonal influenza (OR = 4.41, 95 % CI: 2.44–7.98) and pneumococcal vaccines (OR = 4.43, 95 % CI: 2.92 – 6.75). Participants with a history of certain conditions, such as stroke (OR = 2.26, 95 % CI: 1.13–4.49), were more likely to be vaccinated against HZ. Participants that reported smoking tobacco daily were less likely to be vaccinated against HZ (OR = 0.48, 95 % CI: 0.26–0.89). Participants were less likely to be vaccinated against HZ if they preferred to develop immunity ‘naturally’ (OR = 0.29, 95 % CI: 0.15 – 0.57) or expressed distrust of vaccines (OR = 0.34, 95 % CI: 0.13–0.91).
Further research is required to understand the barriers to HZ vaccine uptake. Increasing the funding eligibility for those who are at risk of complications from shingles, or lowering the age of eligibility, may increase vaccine coverage.
Journal Article
Reduction of secondary transmission of SARS-CoV-2 in households by face mask use, disinfection and social distancing: a cohort study in Beijing, China
2020
IntroductionTransmission of COVID-19 within families and close contacts accounts for the majority of epidemic growth. Community mask wearing, hand washing and social distancing are thought to be effective but there is little evidence to inform or support community members on COVID-19 risk reduction within families.MethodsA retrospective cohort study of 335 people in 124 families and with at least one laboratory confirmed COVID-19 case was conducted from 28 February to 27 March 2020, in Beijing, China. The outcome of interest was secondary transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within the family. Characteristics and practices of primary cases, of well family contacts and household hygiene practices were analysed as predictors of secondary transmission.ResultsThe secondary attack rate in families was 23.0% (77/335). Face mask use by the primary case and family contacts before the primary case developed symptoms was 79% effective in reducing transmission (OR=0.21, 95% CI 0.06 to 0.79). Daily use of chlorine or ethanol based disinfectant in households was 77% effective (OR=0.23, 95% CI 0.07 to 0.84). Wearing a mask after illness onset of the primary case was not significantly protective. The risk of household transmission was 18 times higher with frequent daily close contact with the primary case (OR=18.26, 95% CI 3.93 to 84.79), and four times higher if the primary case had diarrhoea (OR=4.10, 95% CI 1.08 to 15.60). Household crowding was not significant.ConclusionThe study confirms the highest risk of transmission prior to symptom onset, and provides the first evidence of the effectiveness of mask use, disinfection and social distancing in preventing COVID-19. We also found evidence of faecal transmission. This can inform guidelines for community prevention in settings of intense COVID-19 epidemics.
Journal Article
Navigating post-vaccine COVID-19 futures in the health and economic context
2021
Phase 3 trials show 63–95% efficacy against symptomatic infection, with the highest efficacy shown for mRNA vaccines.2–4 The ChAdOx1 nCoV-19 vaccine trial is the only one to date presenting data on prevention of asymptomatic infection, and efficacy is much lower for this endpoint.2 Economic losses are substantially less when high-efficacy vaccines are used, whereas lower-efficacy vaccines with short duration of protection will provide marginal benefits compared with no vaccination.1 The best-case vaccination scenario will result in substantial economic gains compared with no vaccination, but the worst-case scenario might not, depending on vaccine costs and the wider societal cost of ongoing lockdowns. Duration of vaccine-induced immunity is also an important factor that affects the economic value of vaccination, but vaccine-induced protection could be extended by boosters. [...]the most influential factor is the efficacy of the vaccines being used, and thus vaccine choices matter enormously for economic recovery. The study shows that if natural immunity is long lasting, the economic value of immunisation decreases.1 However, the mRNA vaccines result in higher neutralising antibody titres than in convalescent sera.5 Furthermore, in Manaus, Brazil, where 76% of the population had been infected by October, 2020—higher than the hypothesised herd immunity threshold—a large second wave has since occurred.6 In addition, variants of concern show evidence of vaccine escape.7 The South African Government paused the planned rollout of the ChAdOx1 nCoV-19 vaccine because the efficacy against the B1.351 variant was found to be 10·4%.8 All vaccines can be matched to emergent variants, but we are likely to face a situation of regular revision of vaccine antigens, which will add to future cost.
Journal Article
Contamination by respiratory viruses on outer surface of medical masks used by hospital healthcare workers
2019
Background
Medical masks are commonly used in health care settings to protect healthcare workers (HCWs) from respiratory and other infections. Airborne respiratory pathogens may settle on the surface of used masks layers, resulting in contamination. The main aim of this study was to study the presence of viruses on the surface of medical masks.
Methods
Two pilot studies in laboratory and clinical settings were carried out to determine the areas of masks likely to contain maximum viral particles. A laboratory study using a mannequin and fluorescent spray showed maximum particles concentrated on upper right, middle and left sections of the medical masks. These findings were confirmed through a small clinical study. The main study was then conducted in high-risk wards of three selected hospitals in Beijing China. Participants (
n
= 148) were asked to wear medical masks for a shift (6–8 h) or as long as they could tolerate. Used samples of medical masks were tested for presence of respiratory viruses in upper sections of the medical masks, in line with the pilot studies.
Results
Overall virus positivity rate was 10.1% (15/148). Commonly isolated viruses from masks samples were
adenovirus
(
n
= 7),
bocavirus
(
n
= 2),
respiratory syncytial virus
(n = 2) and
influenza virus
(n = 2). Virus positivity was significantly higher in masks samples worn for > 6 h (14.1%, 14/99 versus 1.2%, 1/49, OR 7.9, 95% CI 1.01–61.99) and in samples used by participants who examined > 25 patients per day (16.9%, 12/71 versus 3.9%, 3/77, OR 5.02, 95% CI 1.35–18.60). Most of the participants (83.8%, 124/148) reported at least one problem associated with mask use. Commonly reported problems were pressure on face (16.9%, 25/148), breathing difficulty (12.2%, 18/148), discomfort (9.5% 14/148), trouble communicating with the patient (7.4%, 11/148) and headache (6.1%, 9/148).
Conclusion
Respiratory pathogens on the outer surface of the used medical masks may result in self-contamination. The risk is higher with longer duration of mask use (> 6 h) and with higher rates of clinical contact. Protocols on duration of mask use should specify a maximum time of continuous use, and should consider guidance in high contact settings. Viruses were isolated from the upper sections of around 10% samples, but other sections of masks may also be contaminated. HCWs should be aware of these risks in order to protect themselves and people around them.
Journal Article