scholarly journals Optimized delay of the second COVID-19 vaccine dose reduces ICU admissions

2021 ◽  
Vol 118 (35) ◽  
pp. e2104640118
Author(s):  
Paulo J. S. Silva ◽  
Claudia Sagastizábal ◽  
Luís Gustavo Nonato ◽  
Claudio José Struchiner ◽  
Tiago Pereira
Keyword(s):  
Vaccine Dose ◽  
Vaccine Production ◽  
Partial Protection ◽  
Degree Of Protection ◽  
Optimal Delay ◽  
Delay Duration ◽  
Optimal Duration ◽  
Production And Distribution ◽  
Number Of Individuals ◽  
Dose Delay

Slower than anticipated, COVID-19 vaccine production and distribution have impaired efforts to curtail the current pandemic. The standard administration schedule for most COVID-19 vaccines currently approved is two doses administered 3 to 4 wk apart. To increase the number of individuals with partial protection, some governments are considering delaying the second vaccine dose. However, the delay duration must take into account crucial factors, such as the degree of protection conferred by a single dose, the anticipated vaccine supply pipeline, and the potential emergence of more virulent COVID-19 variants. To help guide decision-making, we propose here an optimization model based on extended susceptible, exposed, infectious, and removed (SEIR) dynamics that determines the optimal delay duration between the first and second COVID-19 vaccine doses. The model assumes lenient social distancing and uses intensive care unit (ICU) admission as a key metric while selecting the optimal duration between doses vs. the standard 4-wk delay. While epistemic uncertainties apply to the interpretation of simulation outputs, we found that the delay is dependent on the vaccine mechanism of action and first-dose efficacy. For infection-blocking vaccines with first-dose efficacy ≥50%, the model predicts that the second dose can be delayed by ≥8 wk (half of the maximal delay), whereas for symptom-alleviating vaccines, the same delay is recommended only if the first-dose efficacy is ≥70%. Our model predicts that a 12-wk second-dose delay of an infection-blocking vaccine with a first-dose efficacy ≥70% could reduce ICU admissions by 400 people per million over 200 d.

scholarly journals “Conquering COVID: How Global Vaccine Inequality Risks Prolonging the Pandemic”

2021 ◽  
Author(s):  
Richard L Oehler ◽  
Vivian R Vega
Keyword(s):  
Modern Science ◽  
Developed Countries ◽  
The United States ◽  
Developing Nations ◽  
Vaccine Production ◽  
The World ◽  
Production And Distribution ◽  
Health Related ◽  
Developed Nations ◽  
Vaccine Availability

Abstract The development of effective vaccines during the SARS-CoV-2 pandemic has been credited as a towering achievement in modern science. Since the end of 2020, the vaccine rollout has offered the promise of vanquishing the pandemic in the United States and other developed countries. Even as the U.S. and other wealthier nations encounter both setbacks and successes in their COVID-19 eradication efforts, developing countries around the world are likely to face far less fortunate fates. With much of the world’s vaccine production and distribution capacity reserved by wealthier nations, impoverished countries stand to face devastating financial, social, and health-related impacts. The consequences of this disparity will resonate deeply into the collective fabric of these countries, ensuring that the economic and geopolitical imbalance between developed and developing nations will widen even more substantially. Wealthier countries must do more to eliminate the inequality that exists in widespread SARS-CoV-2 vaccine availability in less-developed nations. Like HIV, TB, Malaria, and other global epidemics, COVID-19 cannot be forgotten just because the pandemic is eventually contained from the shores of wealthier nations. For as long as the pandemic rages in any corner of the globe, the world will never be truly rid of COVID-19. And all nations, rich or poor, will suffer the consequences.

scholarly journals Ultra-low dose immunization and multi-component vaccination strategies enhance protection against malaria in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Katharine A. Collins ◽  
Florian Brod ◽  
Rebecca Snaith ◽  
Marta Ulaszewska ◽  
Rhea J. Longley ◽  
...  
Keyword(s):  
Viral Vectors ◽  
Low Dose ◽  
Protective Efficacy ◽  
Vaccine Dose ◽  
Effective Vaccine ◽  
Phase 3 ◽  
Partial Protection ◽  
Potential Efficacy ◽  
Transgenic Parasites ◽  
Dose Vaccine

AbstractAn effective vaccine would be a valuable tool for malaria control and elimination; however, the leading malaria vaccine in development, RTS,S/AS01, provided only partial protection in a Phase 3 trial. R21 is a next-generation RTS,S-like vaccine. We have previously shown in mice that R21 administered in Matrix-M is highly immunogenic, able to elicit complete protection against sporozoite challenge, and can be successfully administered with TRAP based viral-vectors resulting in enhanced protection. In this study, we developed a novel, GMP-compatible purification process for R21, and evaluated the immunogenicity and protective efficacy of ultra-low doses of both R21 and RTS,S when formulated in AS01. We demonstrated that both vaccines are highly immunogenic and also elicit comparable high levels of protection against transgenic parasites in BALB/c mice. By lowering the vaccine dose there was a trend for increased immunogenicity and sterile protection, with the highest dose vaccine groups achieving the lowest efficacy (50% sterile protection). We also evaluated the ability to combine RTS,S/AS01 with TRAP based viral-vectors and observed concurrent induction of immune responses to both antigens with minimal interference when mixing the vaccines prior to administration. These studies suggest that R21 or RTS,S could be combined with viral-vectors for a multi-component vaccination approach and indicate that low dose vaccination should be fully explored in humans to maximize potential efficacy.

scholarly journals Tracking COVID-19 vaccine hesitancy and logistical challenges: A machine learning approach

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252332
Author(s):  
Shantanu Dutta ◽  
Ashok Kumar ◽  
Moumita Dutta ◽  
Caolan Walsh
Keyword(s):  
Machine Learning ◽  
Language Processing ◽  
Vaccine Hesitancy ◽  
Vaccine Production ◽  
Machine Learning Approach ◽  
Production And Distribution ◽  
The Usa ◽  
Physical Effects ◽  
Processing Techniques ◽  
Health Administrators

In this study, we use an effective word embedding model (word2vec) to systematically track ’vaccine hesitancy’ and ’logistical challenges’ associated with the Covid-19 vaccines, in the USA. To that effect, we use news articles from reputed media sources and create dictionaries to estimate different aspects of vaccine hesitancy and logistical challenges. Using machine learning and natural language processing techniques, we have developed (i) three sub-dictionaries that indicate vaccine hesitancy, and (ii) another dictionary for logistical challenges associated with vaccine production and distribution. Vaccine hesitancy dictionaries capture three aspects: (a) general vaccine related concerns, mistrusts, skepticisms, and hesitancy, (b) discussions on symptoms and side-effects, and (c) discussions on vaccine related physical effects. The dictionary on logistical challenges includes the words and phrases related to the production, storage, and distribution of vaccines. Our results show that over time, as vaccine developers complete different phase trials and get approval for their respective vaccines, the number of vaccine related news articles increases sharply. Accordingly, we also see a sharp increase in vaccine hesitancy related topics in news articles. However, in January 2021, there has been a decrease in the vaccine hesitancy score, which will give some relief to the health administrators and regulators. Our findings further show that as we get closer to the breakthrough of effective Covid-19 vaccines, new logistical challenges continue to rise, even in recent months.

scholarly journals Experimental substantiation of the use of a small dose of the vaccine to prevent the specific brucellosis of cattle

2020 ◽  
Vol 27 ◽  
pp. 00136
Author(s):  
Aleksei Alekseevich Novitsky ◽  
Valentina Ivanovna Pleshakova ◽  
Nadezhda Alekseevna Lescheva ◽  
Vasilii Sergeevich Vlasenko
Keyword(s):  
Immune Response ◽  
Small Dose ◽  
Vaccine Dose ◽  
Urgent Problem ◽  
Vaccine Production ◽  
Adult Cattle ◽  
Post Vaccination ◽  
Full Dose ◽  
Small Doses ◽  
Experimental Substantiation

The expansion of zones with the cattle without anti-brucellosis immunity in healthy areas increases the risk of cattle infection from neighboring infected regions and states. There is an urgent problem of developing the anti-brucellosis immunity in the adult cattle. The initial full-dose vaccination with the vaccine from strain B. abortus 82 is fraught with post-vaccination abortion. The study is aimed at the exploration of the immune response and immunity in cows vaccinated against brucellosis according to different schemes with small doses of vaccines from B. abortus strains 19 and 82. The results of the experiment showed that the small-dose revaccination with a vaccine from strain 82 is the most promising, because without any harm to the formed immunity, the problem associated with the reactogenicity and agglutinogenicity of the vaccine can be solved. In addition, a ten-time reduction in the vaccine dose can reduce vaccine production volumes and decrease financial expenses of the farmers.

scholarly journals Vaccine and Monoclonal Antibody That Enhance Mouse Resistance to Candidiasis

2011 ◽  
Vol 18 (10) ◽  
pp. 1656-1667 ◽  
Author(s):  
Hong Xin ◽  
Jim E. Cutler
Keyword(s):  
Monoclonal Antibody ◽  
Immune Serum ◽  
Terminal Portion ◽  
Partial Protection ◽  
Content Type ◽  
Degree Of Protection ◽  
Mhc Ii ◽  
Histocompatibility Complex ◽  
Class Ii Mhc ◽  
High Degree

ABSTRACTPreviously we showed that antibodies specific for the glycan β-1,2-mannotriose [β-(Man)3] on the cell surface ofCandida albicansprotect mice against disseminated candidiasis (H. Xin, S. Dziadek, D. R. Bundle, and J. E. Cutler, Proc. Natl. Acad. Sci. U. S. A. 105:13526–13531, 2008). Furthermore, six 14-mer peptides that are within the N-terminal portion ofC. albicanswall proteins were conjugated to the glycan in an attempt to create immunogenic glycopeptide conjugates. By a dendritic cell (DC)-based immunization approach, all were immunogenic and three of the six conjugates induced a high degree of protection in mice. Interestingly, whereas all six peptides induced antibody responses when used alone to pulse DCs for subsequent immunizations, three peptides induced protection, and one in particular, peptide Fba (derived fromfructose-bisphosphatealdolase), induced robust protective responses and is the focus of the current work. Fba peptide is not restricted by the major histocompatibility complex class II (MHC-II), as it induced anti-Fba antibodies in mice of different H-2 haplotypes and in rabbits. Furthermore, the peptide induced protection against disease caused by differentC. albicansstrains. Partial protection was achieved when alum was used in place of DCs for Fba immunizations. The passive transfer of immune sera from Fba-vaccinated mice, but not immune serum preabsorbed with fungal cells, conferred protection in naïve mice. This result, along with our finding that a monoclonal antibody specific for the peptide, E2-9 (IgM), protected mice against candidiasis, provide strong evidence that antibodies contribute to protection. Our work demonstrates the utility of cell wall peptides alone or as glycopeptides in vaccines designed for the induction of immunity against candidiasis and monoclonal antibodies as a rapid immunoprotective approach against the disease.

scholarly journals Induction of Immune Response and Protective Immunity by a Local Isolated Varicella Virus in Animal Model: A Future Candidates for Vaccine Production

2019 ◽  
Author(s):  
Fatemeh Esna-Ashari ◽  
Farzaneh Sabahi ◽  
Mehrdad Ravanshad ◽  
Ashraf Mohammadi
Keyword(s):  
Cell Culture ◽  
Immune Response ◽  
Guinea Pig ◽  
Varicella Zoster Virus ◽  
Vaccine Dose ◽  
Culture Fluid ◽  
Fibroblast Cell ◽  
Vaccine Production ◽  
Varicella Zoster ◽  
Humoral Immune

Preparation of the indigenous varicella zoster vaccine could significantly reduce the disease burden of varicella zoster virus especially in immunosuppressed children. To achieve this goal, the varicella zoster virus was isolated from an 8 years boy infected with chicken pox. The virus was cultivated in sensitive cell line and determined varicella zoster. The adaptation and attenuation of virus was carried out after several passages in MRC-5 cell culture, Primary Guinea pig embryo fibroblast cell culture and again switching in MRC-5 cell culture. The challenged of vaccine dose was found 3LogCCID50. Following two doses of immunization in guinea pigs via inoculated cell culture-fluid attenuated- local isolated VZV at zero and 14 day, the humoral immune response, varicella-zoster virus (VZV) IgG and IgM were determined using enzyme-linked Immunosorbent and seroneutralization assays at 7, 14, 21, 30, 60, 90.120 days after receiving of the first and second dose of vaccine. The results of immunization showed good 93% seroconversion in guinea pig which compared with vOKa vaccine was not significant (p<0.05). The prepared attenuate varicella zoster virus promising a candidate Virus for our future plan to vaccine production.

Influence of thromboxane inhibition on the severity of myocardial ischemia in cats

1980 ◽  
Vol 58 (3) ◽  
pp. 294-300 ◽  
Author(s):  
Edward F. Smith III ◽  
Allan M. Lefer ◽  
J. Bryan Smith
Keyword(s):  
Myocardial Ischemia ◽  
Nitrogen Content ◽  
Creatine Phosphokinase ◽  
Amino Nitrogen ◽  
Myocardial Tissue ◽  
Significant Protection ◽  
Partial Protection ◽  
Content Assessment ◽  
Degree Of Protection ◽  
Acute Mi

The effects of thromboxane (Tx) inhibition or arachidonic acid (AA) infusion were studied in anesthetized cats during acute myocardial ischemia (MI). AA (7.2 mg kg−1 h−1) or imidazole (25 mg kg−1 h−1) infusions were initiated 30 min after occlusion of the left anterior descending coronary artery. Assessment of the degree of protection of the ischemic myocardium was made by measurement of S-T segment elevation, plasma and myocardial creatine phosphokinase (CPK) activities, and myocardial amino-nitrogen content. Assessment of Tx inhibition was performed by radioimmunoassay. Administration of imidazole inhibited the sevenfold increase in plasma thromboxane B2 (TxB2) levels occurring in MI (p < 0.001 at 2–5 h), markedly decreased S-T segment elevations at 2–5 h (p < 0.025), significantly prevented the elevation in plasma CPK (p < 0.05, at 4 and 5 h), and significantly reduced the loss in myocardial CPK activity and myocardial amino-nitrogen content. AA infusion also reduced the increase in TxB2 post-MI, significantly decreased (p < 0.025) S-T segment elevations at 2 5 h, caused a decrease in plasma CPK levels (p < 0.05 at 5 h), but did not prevent loss of myocardial CPK or amino-nitrogen. In summary, the administration of imidazole resulted in significant protection of the myocardium in all indices of ischemic damage measured, while AA infusion resulted in only a partial protection. The mechanism of the imidazole protection of ischemic myocardial tissue appears to be via inhibition of Tx synthesis although we cannot exclude a hemodynamic or cytoprotective mechanism. These results suggest that specific inhibition of Tx formation is beneficial during acute MI.

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