scholarly journals Intranasal Vaccination Strategy to Control the COVID-19 Pandemic from a Veterinary Medicine Perspective

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1876
Author(s):  
Salleh Annas ◽  
Mohd Zamri-Saad
Keyword(s):  
Veterinary Medicine ◽  
Vaccination Coverage ◽  
Herd Immunity ◽  
Vaccination Strategy ◽  
Current Control ◽  
Control Measures ◽  
Vaccine Strategy ◽  
Infectious Bronchitis ◽  
Intranasal Vaccine ◽  
Potential Use

The world is currently facing an ongoing coronavirus disease 2019 (COVID-19) pandemic. The disease is a highly contagious respiratory disease which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current control measures used by many countries include social distancing, wearing face masks, frequent hand washing, self-isolation, and vaccination. The current commercially available vaccines are injectable vaccines, although a few intranasal vaccines are in trial stages. The reported side effects of COVID-19 vaccines, perceptions towards the safety of the vaccines, and frequent mutation of the virus may lead to poor herd immunity. In veterinary medicine, attaining herd immunity is one of the main considerations in disease control, and herd immunity depends on the use of efficacious vaccines and the vaccination coverage in a population. Hence, many aerosol or intranasal vaccines have been developed to control veterinary respiratory diseases such as Newcastle disease, rinderpest, infectious bronchitis, and haemorrhagic septicaemia. Different vaccine technologies could be employed to improve vaccination coverage, including the usage of an intranasal live recombinant vaccine or live mutant vaccine. This paper discusses the potential use of intranasal vaccination strategies against human COVID-19, based on a veterinary intranasal vaccine strategy.

scholarly journals Occurrence and molecular detection of avian coronavirus in selected live bird markets, northwestern, Nigeria

2021 ◽  
Vol 18 (4) ◽  
pp. 226-229
Author(s):  
I . Bitrus ◽  
I. Shittu ◽  
C.A. Meseko ◽  
T.M. Joannis
Keyword(s):  
Infectious Bronchitis Virus ◽  
Molecular Detection ◽  
Vaccination Strategy ◽  
Guinea Fowl ◽  
Avian Species ◽  
Control Measures ◽  
Infectious Bronchitis ◽  
Live Bird Markets ◽  
Local Chicken ◽  
Live Bird

Infectious bronchitis (IB) is one of the most common highly infectious viral respiratory diseases of poultry having wide geographical  distribution. Yet, little is known about the infection in the northwestern states of Nigeria. In this study, a total of 263 pooled cloacal and tracheal swab samples were collected from apparently healthy avian species (duck, dove, geese, guinea fowl, local chicken, ostrich, parrot, pigeon, peacock, and turkey). The samples were from nine live bird markets in three states (Kaduna, Kano and Jigawa) of northwestern,  Nigeria collected from September through November 2017. Total RNAs were extracted directly from the swab samples and screened for infectious bronchitis virus (IBV) using real-time reverse transcription-polymerase chain reaction. An overall prevalence of 38.0% (100/263)was recorded. IB was detected in 70 % (7/10) of the avian species with prevalence of 100 % in dove, local chicken 45.9 %, duck 42.3 %, geese 26.6 %, pigeon 23.5 %, turkey 20.0 % and guinea fowl 6.2 %. Conversely, no detection was made from ostrich, parrot, and peacock.  Widespread distribution of IBV was observed and evidence of subclinical infection in seven out of ten (70 %) of the avian species sampled. These avian species harbouring IBV may act as reservoirs with an influence on the ecology and epidemiology of the disease. Continuous surveillance and characterization of the different serotypes in avian species are recommended to inform the adoption of suitable  vaccination strategy and control measures for the disease in Nigeria. Keywords: Infectious bronchitis virus, Live bird markets (LBMs), Molecular detection, Nigeria, Poultry

scholarly journals Influence of heterogeneous age-group contact patterns on critical vaccination rates for herd immunity to SARS-CoV-2

2021 ◽  
Author(s):  
Joan Saldana ◽  
Caterina M Scoglio
Keyword(s):  
Vaccination Coverage ◽  
Herd Immunity ◽  
Age Groups ◽  
Social Contact ◽  
Vaccination Strategy ◽  
Primary Concern ◽  
Vaccination Rates ◽  
Contact Patterns ◽  
Group Contact ◽  
Age Structured

Currently, several western countries have more than half of their population fully vaccinated against COVID-19. At the same time, some of them are experiencing a fourth or even a fifth wave of cases, most of them concentrated in sectors of the populations whose vaccination coverage is lower than the average. So, the initial scenario of vaccine prioritization has given way to a new one where achieving herd immunity is the primary concern. Using an age-structured vaccination model with waning immunity, we show that, under a limited supply of vaccines, a vaccination strategy based on minimizing the basic reproduction number allows for the deployment of a number of vaccine doses lower than the one required for maximizing the vaccination coverage. Such minimization is achieved by giving greater protection to those age groups that, for a given social contact pattern, have smaller fractions of susceptible individuals at the endemic equilibrium without vaccination, that is, to those groups that are more vulnerable to infection.

scholarly journals COVID-19 Network Model to Evaluate Vaccine Strategies towards Herd Immunity

2020 ◽  
Author(s):  
Josephine N. A. Tetteh ◽  
Van Kinh Nguyen ◽  
Esteban A. Hernandez-Vargas
Keyword(s):  
Public Health ◽  
Network Model ◽  
Vaccine Efficacy ◽  
Herd Immunity ◽  
Vaccination Strategy ◽  
Critical Element ◽  
Computational Simulations ◽  
Vaccine Strategy ◽  
Health Crisis ◽  
Public Health Crisis

AbstractWith more than 60 million confirmed cases and more than 1.5 million deaths, SARS-CoV-2 has paralyzed our societies, leading to self isolation and quarantine for several months. A COVID-19 vaccine remains a critical element in the eventual solution to this public health crisis. Two vaccines are ready to be mass produced and eventually supplied to the population. Here, we develop an epidemiological network model able to represent COVID-19 pandemic dynamics of different countries such as in Italy. Stochastic computational simulations identify the necessary number of vaccines and vaccine efficacy thresholds capable of preventing an epidemic whilst adhering to lockdown guidelines. Assuming a vaccine efficacy of 100% in a mass vaccination program, at least 60% of a given population should be vaccinated to obtain herd immunity. Otherwise, new waves of COVID-19 would be reported. However, reaching 60% of the population will be an unprecedented mass immunisation campaign that will take several months and millions of dollars. If the vaccine efficacy reports lower levels of efficacy in practice, then the coverage of vaccination would be needed to be even higher. Simulations suggest that the “Ring of Vaccination” strategy, vaccinating susceptible contact and contact of contacts, would be a more tractable vaccine strategy to prevent the new waves of COVID-19 meanwhile a high percent of the population is vaccinated.

scholarly journals A prognostic dynamic model applicable to infectious diseases providing easily visualized guides: a case study of COVID-19 in the UK

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuxuan Zhang ◽  
Chen Gong ◽  
Dawei Li ◽  
Zhi-Wei Wang ◽  
Shengda D. Pu ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Disease Control ◽  
Control Strategies ◽  
Herd Immunity ◽  
Iterative Algorithms ◽  
Vaccination Strategy ◽  
Control Measures ◽  
Transmission Model ◽  
Government Interventions ◽  
The Uk

AbstractA reasonable prediction of infectious diseases’ transmission process under different disease control strategies is an important reference point for policy makers. Here we established a dynamic transmission model via Python and realized comprehensive regulation of disease control measures. We classified government interventions into three categories and introduced three parameters as descriptions for the key points in disease control, these being intraregional growth rate, interregional communication rate, and detection rate of infectors. Our simulation predicts the infection by COVID-19 in the UK would be out of control in 73 days without any interventions; at the same time, herd immunity acquisition will begin from the epicentre. After we introduced government interventions, a single intervention is effective in disease control but at huge expense, while combined interventions would be more efficient, among which, enhancing detection number is crucial in the control strategy for COVID-19. In addition, we calculated requirements for the most effective vaccination strategy based on infection numbers in a real situation. Our model was programmed with iterative algorithms, and visualized via cellular automata; it can be applied to similar epidemics in other regions if the basic parameters are inputted, and is able to synthetically mimic the effect of multiple factors in infectious disease control.

scholarly journals Phylogenetic Complexity of Morphologically Identified Anopheles squamosus in Southern Zambia

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 146
Author(s):  
Jordan Hoffman ◽  
Ilinca Ciubotariu ◽  
Limonty Simubali ◽  
Twig Mudenda ◽  
William Moss ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Catchment Area ◽  
Control Strategies ◽  
Light Trap ◽  
Current Control ◽  
Control Measures ◽  
Morphological Identification ◽  
The Past ◽  
Blood Meal Source ◽  
Residual Malaria Transmission

Despite dramatic reductions in malaria cases in the catchment area of Macha Hospital, Choma District, Southern Province in Zambia, prevalence has remained near 1–2% by RDT for the past several years. To investigate residual malaria transmission in the area, this study focuses on the relative abundance, foraging behavior, and phylogenetic relationships of Anopheles squamosus specimens. In 2011, higher than expected rates of anthropophily were observed among “zoophilic” An. squamosus, a species that had sporadically been found to contain Plasmodium falciparum sporozoites. The importance of An. squamosus in the region was reaffirmed in 2016 when P. falciparum sporozoites were detected in numerous An. squamosus specimens. This study analyzed Centers for Disease Control (CDC) light trap collections of adult mosquitoes from two collection schemes: one performed as part of a reactive-test-and-treat program and the second performed along a geographical transect. Morphological identification, molecular verification of anopheline species, and blood meal source were determined on individual samples. Data from these collections supported earlier studies demonstrating An. squamosus to be primarily exophagic and zoophilic, allowing them to evade current control measures. The phylogenetic relationships generated from the specimens in this study illustrate the existence of well supported clade structure among An. squamosus specimens, which further emphasizes the importance of molecular identification of vectors. The primarily exophagic behavior of An. squamosus in these collections also highlights that indoor vector control strategies will not be sufficient for elimination of malaria in southern Zambia.

scholarly journals Rotavirus Vaccination of Infants Delayed and Limited within the National Immunization Programme in the Netherlands: An Opportunity Lost

Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 144
Author(s):  
Florian Zeevat ◽  
Evgeni Dvortsin ◽  
Abrham Wondimu ◽  
Jan C. Wilschut ◽  
Cornelis Boersma ◽  
...  
Keyword(s):  
High Risk ◽  
The Netherlands ◽  
Herd Immunity ◽  
Vaccination Strategy ◽  
Quality Adjusted Life Year ◽  
High Risk Group ◽  
Universal Vaccination ◽  
Birth Cohorts ◽  
Rotavirus Vaccination ◽  
Immunization Programme

In this study, we estimated the benefits of rotavirus vaccination for infants had the rotavirus vaccine been introduced in the Netherlands as of its market authorization in 2006. An age-structured, deterministic cohort model was developed to simulate different birth cohorts over a period of 15 years from 2006 until 2021, comparing both universal and targeted high-risk group vaccination to no vaccination. Different scenarios for the duration of protection (5 or 7 years) and herd immunity (only for universal vaccination) were analyzed. All birth cohorts together included 2.6 million infants, of which 7.9% were high-risk individuals, and an additional 13.2 million children between 1–15 years born prior to the first cohort in 2006. The costs and health outcomes associated with rotavirus vaccination were calculated per model scenario and discounted at 4% and 1.5%, respectively. Our analysis reveals that, had rotavirus vaccination been implemented in 2006, it would have prevented 356,800 (51% decrease) and 32,200 (5% decrease) cases of rotavirus gastroenteritis after universal and targeted vaccination, respectively. Over the last 15 years, this would have led to significant avoided costs and quality-adjusted life year losses for either vaccination strategy with the most favorable outcomes for universal vaccination. Clearly, an opportunity has been lost.

scholarly journals Timing and Route of Contamination of Patient Rooms With Healthcare-Associated Pathogens

2020 ◽  
Vol 41 (S1) ◽  
pp. s412-s412
Author(s):  
Sarah Redmond ◽  
Jennifer Cadnum ◽  
Basya Pearlmutter ◽  
Natalia Pinto Herrera ◽  
Curtis Donskey
Keyword(s):  
Acute Care Hospital ◽  
Current Control ◽  
Pathogen Transmission ◽  
Control Measures ◽  
Effective Control ◽  
Portable Devices ◽  
Care Hospital ◽  
Spa Typing ◽  
Persistent Problem ◽  
Healthcare Associated

Background: Transmission of healthcare-associated pathogens such as Clostridioides difficile and methicillin-resistant Staphylococcus aureus (MRSA) is a persistent problem in healthcare facilities despite current control measures. A better understanding of the routes of pathogen transmission is needed to develop effective control measures. Methods: We conducted an observational cohort study in an acute-care hospital to identify the timing and route of transfer of pathogens to rooms of newly admitted patients with negative MRSA nares results and no known carriage of other healthcare-associated pathogens. Rooms were thoroughly cleaned and disinfected prior to patient admission. Interactions of patients with personnel and portable equipment were observed, and serial cultures for pathogens were collected from the skin of patients and from surfaces, including those observed to come in contact with personnel and equipment. For MRSA, spa typing was used to determine relatedness of patient and environmental isolates. Results: For the 17 patients enrolled, 1 or more environmental cultures became positive for MRSA in rooms of 10 patients (59%), for C. difficile in rooms of 2 patients (12%) and for vancomycin-resistant enterococci (VRE) in rooms of 2 patients (12%). The patients interacted with an average of 2.4 personnel and 0.6 portable devices per hour of observation. As shown in Figure 1, MRSA contamination of the floor occurred rapidly as personnel entered the room. In a subset of patients, MRSA was subsequently recovered from patients’ socks and bedding and ultimately from the high-touch surfaces in the room (tray table, call button, bedrail). For several patients, MRSA isolates recovered from the floor had the same spa type as isolates subsequently recovered from other sites (eg, socks, bedding, and/or high touch surfaces). The direct transfer of healthcare-associated pathogens from personnel or equipment to high-touch surfaces was not detected. Conclusions: Healthcare-associated pathogens rapidly accumulate on the floor of patient rooms and can be transferred to the socks and bedding of patients and to high-touch surfaces. Healthcare facility floors may be an underappreciated source of pathogen dissemination not addressed by current infection control measures.Funding: NoneDisclosures: None

scholarly journals The importance of supplementary immunisation activities to prevent measles outbreaks during the COVID-19 pandemic in Kenya

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
C. N. Mburu ◽  
◽  
J. Ojal ◽  
R. Chebet ◽  
D. Akech ◽  
...  
Keyword(s):  
Vaccination Coverage ◽  
Herd Immunity ◽  
African Region ◽  
Population Immunity ◽  
Measles Outbreak ◽  
Increased Risk ◽  
Measles Vaccination ◽  
Serological Data ◽  
Measles Outbreaks ◽  
Measles Vaccination Coverage

Abstract Background The COVID-19 pandemic has disrupted routine measles immunisation and supplementary immunisation activities (SIAs) in most countries including Kenya. We assessed the risk of measles outbreaks during the pandemic in Kenya as a case study for the African Region. Methods Combining measles serological data, local contact patterns, and vaccination coverage into a cohort model, we predicted the age-adjusted population immunity in Kenya and estimated the probability of outbreaks when contact-reducing COVID-19 interventions are lifted. We considered various scenarios for reduced measles vaccination coverage from April 2020. Results In February 2020, when a scheduled SIA was postponed, population immunity was close to the herd immunity threshold and the probability of a large outbreak was 34% (8–54). As the COVID-19 contact restrictions are nearly fully eased, from December 2020, the probability of a large measles outbreak will increase to 38% (19–54), 46% (30–59), and 54% (43–64) assuming a 15%, 50%, and 100% reduction in measles vaccination coverage. By December 2021, this risk increases further to 43% (25–56), 54% (43–63), and 67% (59–72) for the same coverage scenarios respectively. However, the increased risk of a measles outbreak following the lifting of all restrictions can be overcome by conducting a SIA with ≥ 95% coverage in under-fives. Conclusion While contact restrictions sufficient for SAR-CoV-2 control temporarily reduce measles transmissibility and the risk of an outbreak from a measles immunity gap, this risk rises rapidly once these restrictions are lifted. Implementing delayed SIAs will be critical for prevention of measles outbreaks given the roll-back of contact restrictions in Kenya.

scholarly journals Vaccination Coverage for Routine Vaccines and Herd Immunity Levels against Measles and Pertussis in the World in 2019

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 256
Author(s):  
Pedro Plans-Rubió
Keyword(s):  
Vaccination Coverage ◽  
Action Plan ◽  
Herd Immunity ◽  
World Health ◽  
Immunization Programs ◽  
National Immunization ◽  
The World ◽  
Measles Vaccination ◽  
The Mean ◽  
Health Organization

In 2012, the World Health Organization (WHO) established the Global Vaccine Action Plan with the objective to promote essential vaccinations in all countries and achieve at least 90% vaccination coverage for all routine vaccines by 2020. The study assessed the mean percentages of vaccination coverage in 2019 for 13 routine vaccines, vaccination coverage variation from 2015 to 2019, and herd immunity levels against measles and pertussis in 2019 in countries and regions of WHO. In 2019, the mean percentages of vaccination coverage were lower than 90% for 10 (78.9%) routine vaccines. The mean percentages of vaccination coverage also decreased from 2015 to 2019 for six (46.2%) routine vaccines. The prevalence of individuals with vaccine-induced measles immunity in the target measles vaccination population was 88.1%, and the prevalence of individuals with vaccine-induced pertussis immunity in the target pertussis vaccination population was 81.1%. Herd immunity against measles viruses with Ro = 18 was established in 63 (32.5%) countries but not established in any region. Herd immunity against pertussis agents was not established in any country and in any region of WHO. National immunization programs must be improved to achieve ≥90% vaccination coverage in all countries and regions. Likewise, it is necessary to achieve ≥95% vaccination coverage with two doses of measles vaccines and three doses of pertussis vaccines in all countries and regions.

scholarly journals Economic evaluation of options for measles vaccination strategy in a hypothetical Western European country

2003 ◽  
Vol 130 (2) ◽  
pp. 273-283 ◽  
Author(s):  
Ph. BEUTELS ◽  
N. J. GAY
Keyword(s):  
Health Care ◽  
European Country ◽  
Vaccination Coverage ◽  
Vaccination Strategy ◽  
Western European Country ◽  
High Coverage ◽  
The Past ◽  
Care Payer ◽  
Measles Vaccination ◽  
Western European

In this study an analysis was made of economic costs and medical effects (by cost-effectiveness and cost–benefit analysis) associated with measles vaccination in a hypothetical Western European country. We analysed ten vaccination options in terms of past and future vaccination coverage. We show that several of the proposed strategies for improving measles vaccination coverage are preferable to maintaining the existing policies, regardless of past coverage and the viewpoint of the analysis. For society, very high coverage (95%) two-dose vaccination is most optimal, irrespective of past vaccination coverage. The addition of a one-time campaign (to reduce susceptibility in (pre-)adolescent age groups) to such a high coverage two-dose vaccination programme is cost-saving to the health-care payer and to society when coverage in the past was low ([les ]70%). Even when coverage in the past was high (90%) for more than a decade, this ‘maximum strategy’ could be implemented at an acceptable cost to the health-care payer (incremental direct costs per discounted life-year gained <€30000), and at net savings to society.

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