Introduction to Vaccine Efficacy

To investigate the usefulness of a serological assay to predict vaccine efficacy, we analyzed the levels of IgG, IgM, and IgA against the receptor binding domain (RBD) of SARS-CoV-2 in the sera from BNT162b2 vaccinated individuals in Japan.

During the last few months, several RBD (receptor-binding domain) variants have been reported to affect the vaccine efficacy considerably.

Vaccine efficacy (VE) was 74% (95% CI, 63-82) and 77% (95% CI, 67-84) in the low- and high-dose adjuvant groups, respectively.

RESULTS Overall vaccine efficacy against re-challenge was 53% (95% CI: 37-65%), and similar for P-Fx (52% [95% CI: 28-68%]) and NP-Fx (54% [95% CI: 29-70%]).

Quantitative determination of neutralizing antibodies against Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) is paramount in immunodiagnostics, vaccine efficacy testing, and immune response profiling among the vaccinated population.

Variable memory Immune memory against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) helps to determine protection against reinfection, disease risk, and vaccine efficacy.

12x104 PfSPZ-CVac given 28 days apart had 100% vaccine efficacy (VE) against controlled human malaria infection (CHMI) 10 weeks after the last immunization, while the same dose given as three injections five days apart had 63% VE.

Here we optimized regimens for chemoprophylaxis vaccination (CVac), for which aseptic, purified, cryopreserved, infectious Plasmodium falciparum sporozoites (PfSPZ) were inoculated under prophylactic cover with pyrimethamine (PYR) (Sanaria PfSPZ-CVac(PYR)) or chloroquine (CQ) (PfSPZ-CVac(CQ))-which kill liver-stage and blood-stage parasites, respectively-and we assessed vaccine efficacy against homologous (that is, the same strain as the vaccine) and heterologous (a different strain) controlled human malaria infection (CHMI) three months after immunization ( https://clinicaltrials.

Despite evidence of vaccine efficacy in both women, symptoms of coronavirus disease 2019 developed, and they tested positive for SARS-CoV-2 by polymerase-chain-reaction testing.

It is just over a year ago that what we now know as coronavirus disease 2019 (COVID-19) first emerged in Wuhan, China (1) In twelve short months every village, every city in every continent has been affected Hundreds of millions of people have been infected and recovered and over two million of people have tragically died from COVID-19 In reality, many more have lost loved ones Yet we may still be closer to the start of this pandemic than to the end We knew a year ago that this virus had all the characteristics capable of causing a devastating global pandemic An animal virus that had crossed the species barrier and could infect humans, for which humanity had no immunity We knew there was human-to-human transmission, we knew people were infectious when they were asymptomatic or pre-symptomatic, that it could cause a mild illness and also a very severe illness leading tragically to people dying (2) We knew the genomic sequences of the virus and we knew we had no diagnostic tests, no specific treatments, or vaccines We also knew this initially emerged in a very densely populated city with highly connected transport links Since we had all that information at the end of January 2020, the trajectory of the pandemic has in many ways been highly predictable At the dawn of the Lunar New Year, we now face a much less predictable year The recent emergence of more transmissible COVID-19 variants with higher case fatality poses a serious threat to efforts to control the pandemic (3-4) Those variants already identified render anti-viral treatments ineffective, evade immunity from natural infection and, with emerging evidence that some variants reduce efficacy of the first-generation vaccines It is inevitable that further variants will emerge that pose a more significant threat to vaccine efficacy Most first-generation vaccines and treatments target a single virus protein, the spike protein, and are very vulnerable to mutations and emergence of new strains Given that we are currently only finding variants where we have the capability to sequence, and not necessarily where they are occurring, this could already be the case It is not coincidence that the three new variants have been picked up in the last quarter of 2020, we can expect a more rapid evolution of the virus in 2021 and more new variants as it adapts to humans (biological adaptation) and is now under increasing immunological pressure from infection and vaccination (immunological adaptation).

The developed vaccines have been widely used to reduce the risk of potential pandemic; however, the ongoing antigenic drift makes influenza virus escape from host immune response and hampers vaccine efficacy.

These include antimycobacterial activity, modulation of the host immune response, and enhancement of BCG vaccine efficacy.

BACKGROUND In the CYD14 (NCT01373281) and CYD15 (NCT01374516) dengue vaccine efficacy trials, Month 13 neutralizing antibody (nAb) titers correlated inversely with risk of symptomatic, virologically confirmed dengue (VCD) between Month 13 (one month post-final-dose) and Month 25.

In this exploratory study (CYD59, NCT02827162), we evaluated potential associations of host human leukocyte antigen (HLA) alleles with dengue antibody responses, CYD-TDV vaccine efficacy, and virologically-confirmed dengue (VCD) cases.

Discussion This study will evaluate single-dose HPV vaccine efficacy in Africa and has the potential to guide public health policy and increase HPV vaccine coverage.

Evidence on COVID-19 vaccine efficacy/effectiveness (VE) in preventing asymptomatic SARS-CoV-2 infections is needed to guide public health recommendations for vaccinated people.

7 (also called VUI202012/01), contains eight Spike mutations with potential to impact antibody therapy, vaccine efficacy and risk of reinfection.

V1 or 20I), contains eight Spike mutations with potential to impact antibody therapy, vaccine efficacy and risk of reinfection.

No evidence of vaccine efficacy in preventing chronic HCV infection was observed as there was no statistically significant difference in the number of participants developing chronic HCV infection between groups.

No evidence of vaccine efficacy in preventing chronic HCV infection was observed as there was no statistically significant difference in the number of participants developing chronic HCV infection between groups.

This magnitude, termed the critical immunization threshold (q), can be obtained from the classical SIR model equilibrium equation, equaling (1-1/R_0)/{epsilon}, where R_0 is the basic reproduction number and {epsilon} is the vaccine efficacy.

Depending on the parameter values related to contagion and vaccine efficacy, a less responsible behavior post-vaccination can increase the basic reproduction number of the disease as compared to the case with no vaccine.

However, in the wake of the emergence of viral variants, able to evade vaccine induced neutralizing antibodies, real world vaccine efficacy has begun to show differences across the mRNA platforms, suggesting that subtle variation in immune responses induced by the BNT162b2 and mRNA1273 vaccines may provide differential protection.

Moreover, the immune responses induced by vaginal delivery may be influenced by the menstrual cycle, microbiota, or pH and could affect vaccine efficacy.

Although interim results from several large placebo-controlled phase 3 trials demonstrated high vaccine efficacy (VE) against symptomatic COVID-19, it is unknown how effective the vaccines are in preventing people from becoming asymptomatically in- fected and potentially spreading the virus unwittingly.

Although interim results from several large, placebo-controlled, phase 3 trials demonstrated high vaccine efficacy (VE) against symptomatic coronavirus disease 2019 (COVID-19), it is unknown how effective the vaccines are in preventing people from becoming asymptomatically infected and potentially spreading the virus unwittingly.

During a median follow-up period of 43 days (IQR 36–48), nine cases of PCR-confirmed symptomatic COVID-19 were reported in the vaccine group (31·7 cases [14·6–59·3] per 1000 person-years) and 32 cases were reported in the placebo group (192·3 cases [135·7–261·1] per 1000 person-years) 14 days or more after the second dose, yielding a vaccine efficacy of 83·5% (95% CI 65·4–92·1; p<0·0001).

1) per 1000 person-years) 14 days or more after the second dose, yielding a vaccine efficacy of 83.

Results This review will present and discuss some coronavirus disease 19 (COVID-19) related aspects including: the pathophysiology, epidemiology, mutant variants vaccine candidates, vaccine efficacy, and management strategies.

Background: In the Coronavirus Efficacy (COVE) trial, estimated mRNA-1273 vaccine efficacy against coronavirus disease-19 (COVID-19) was 94%.

Methods In this ongoing, double-blind, randomized, placebo-controlled, phase 3 clinical trial, we investigated the safety, vaccine efficacy, and immunogenicity of two doses of AZD1222 as compared with placebo in preventing the onset of symptomatic and severe coronavirus disease 2019 (Covid-19) 15 days or more after the second dose in adults, including older adults, in the United States, Chile, and Peru.

Understanding and Communicating about COVID-19 Vaccine Efficacy, Effectiveness, and Equity.

Although specific COVID-19-related studies are needed, data from investigations with other types of infectious agents, such as influenza, support the potential role of physical activity in augmenting COVID-19 vaccine efficacy (secondary prevention level).

Despite intensive research, there is no vaccine available; therefore, new approaches are needed to further improve vaccine efficacy.

Above all, we have a duty to perform high quality science to investigate mechanisms underlying immune responses to infectious diseases, with the aim not only to understand the disease better, but also to identify new avenues to improve vaccine efficacy and minimizing side effects.

1) highlighting a high vaccine efficacy against B.

However, the high vaccine efficacy reported by ongoing phase 3 placebo-controlled clinical trials is based on a median follow-up time of only about two months and thus does not pertain to long-term efficacy.

Awareness of the identified COVID-19 risk factors and successful surveillance strategies are key to protecting HCWs against SARS-CoV-2, especially in settings with limited vaccination capacities or reduced vaccine efficacy.

Importance Antibiotic-induced gut microbiome disruption has been linked to reduced vaccine efficacy.

To investigate the usefulness of a serological assay to predict vaccine efficacy, we analyzed the levels of IgG, IgM, and IgA against the receptor binding domain (RBD) of SARS-CoV-2 in the sera from BNT162b2 vaccinated individuals in Japan.

However, the paucity of studies, the absence of tools to predict vaccine efficacy, and the lack of studies investigating the efficacy of newer vaccines in presence of frailty, strongly limit the formulation of more personalized immunization strategies for older adults.

Accordingly, it is necessary to establish an efficient and accurate methodology to evaluate vaccine efficacy in vivo.

[1] We performed a literature review with the objective to evaluate vaccine efficacy, safety and technology of the COVID-19 vaccines that have reached phase III of clinical development.

Previous systematic reviews concluded uncertain evidence on influenza vaccine efficacy for preventing cardiovascular events in the general population or in populations with pre-existing CVD.

Furthermore, the simulation results suggest that dose fractionation policies take positive effects in lowering the \begin{document}$ \mathscr{R}_0 $\end{document} , decreasing the final size and reducing the infection attack rate only when the fractional-dose influenza vaccine efficacy is high enough rather than just similar to standard-dose.

RESULTS Overall vaccine efficacy against re-challenge was 53% (95% CI: 37-65%), and similar for P-Fx (52% [95% CI: 28-68%]) and NP-Fx (54% [95% CI: 29-70%]).

A leading tetravalent vaccine (Dengvaxia) stimulated NAbs to the 4 DENV serotypes, yet overall vaccine efficacy was low in children who were DENV seronegative at baseline before vaccination.

Adding other influenza surface proteins, such as neuraminidase and M2e, to current quadrivalent influenza vaccines would likely enhance vaccine efficacy.

SnoopLigase conjugation has been applied for enhancing enzyme resilience and for antigen oligomerization to enhance vaccine efficacy.

Current influenza vaccines are updated yearly to include strains predicted to circulate in the upcoming influenza season, however this can lead to a mismatch which reduces vaccine efficacy.

Clinically, immunosenescence refers to the gradual deterioration of immune system that increases exposure to infections, and reduces vaccine efficacy.

Global concerns have been raised for its potential to affect vaccine efficacy.

Moreover, SexHs-specific differences might affect vaccine efficacy and response to treatment.

Vaccination of individuals with rheumatologic diseases on immunomodulators represents an additional challenge because data suggest that certain immunomodulators may impact vaccine efficacy.

7%) adults in the United States according to centers for disease control and prevention (CDC), we propose that they can negatively impact vaccine efficacy.

Serologic testing for SARS-CoV-2 antibodies can be used to confirm diagnosis, estimate seroprevalence, screen convalescent plasma donors, and assess vaccine efficacy.

Randomized vaccine trials are used to assess vaccine efficacy (VE) and to characterize the durability of vaccine‐induced protection.

Unfortunately, vaccination in transplant recipients is challenging due to suboptimal vaccine efficacy which is significantly lower than in the general population (1).

Optimised immunisation in this patient population is challenging because of limited data from vaccine trials, suboptimal vaccine efficacy and safety concerns.

The study investigated the effects of social media exposure/interpersonal discussion on intention of COVID-19 vaccination and tested whether perceived effectiveness of COVID-19 vaccines (perceived vaccine efficacy, perceived duration of protection, and perceived effectiveness in preventing resurgences) mediated such associations.

This experiment assessed how the frame of promotional vaccine messages elicited psychological reactance differently for African American parents according to their level of perceived vaccine efficacy.

Background Haematological malignancies and their treatments are likely to affect SARS-CoV-2 vaccine efficacy.

The empirically-observed dependence of SARS-CoV-2 vaccine efficacy on antibody concentration has a rational explanation in the statistics of binding of antibody to spike proteins on the virus surface: namely that the probability of protection is the probability of antibody binding to more than a critical number of the spike proteins protruding from the virus.

Vaccination aims at reaching sterilizing immunity, however assessing vaccine efficacy is still challenging and underscores the need for a better understanding of immune protective responses.

This study was undertaken with an objective to correlate sample‐to‐cut‐off (S/Co) ratio of CLIA antibody tests with inhibition activity, which may then serve as a valuable guide for labelling plasma as COVID convalescent plasma (CCP) for therapy and assessing vaccine efficacy.

This proves that a single dose of a COVID-19 mRNA vaccine after ChAdOx1 nCoV-19 prime vaccination is sufficient to achieve high neutralizing antibody levels predicting immune protection from SARS-CoV-2 infection, and may even increase vaccine efficacy offering an alternative in a setting of vaccine shortage.

Adjuvants are the helper substances that increase vaccine efficacy by enhancing the potency and longevity of specific immune responses to antigens.

This gene signature was enriched in the partially effective RV144 human trial that administered the ALVAC/protein vaccine, and we find that the signature associates with both decreased risk of HIV-1 acquisition and increased vaccine efficacy.

Envisage with the prevailing pandemics and increasing demands for cancer vaccines, bio-mimic particles were developed to imitate the natural traits of the pathogens, which conferred the optimal strategies to stimulate the immune engagement and let to the increased vaccine efficacy.

Continued follow-up of participants in COVID-19 vaccine trials after vaccination of the placebo group permits determination of vaccine durability and allows the incorporation of a booster trial if waning vaccine efficacy is observed, while ensuring the ethical treatment of participants.

With known waning vaccine efficacy, continued surveillance is needed to ensure these early reductions in incidence are sustained.

Although RCTs are the superior method for evaluating vaccine efficacy, the feasibility of conducting RCTs to monitor COVID-19 vaccine effectiveness during mass vaccine campaigns will likely be low.

Accurate assessment of SARS-CoV-2 immunity in the population is critical to evaluating vaccine efficacy and devising public health policies.

Sensitivity analyses included first dose vaccine efficacy of 50%, 60%, 70%, 80%, and 90% after day 12 post-vaccination; vaccination rate of 0.

Sensitivity analyses include first-dose vaccine efficacy of 70%, 80% and 90% after day 12 post-vaccination; vaccination rate of 0.

Several CHIKV animal models exist; however, not all provide suitable endpoints for measuring vaccine efficacy.

Such antibodies would be valuable for measuring vaccine efficacy, diagnosing exposure, and developing effective biotherapeutics.

Comparatively, however, the development of new adjuvants capable of enhancing vaccine efficacy has been lagging.

The covalent tethering of TLR agonists to antigenic proteins offers a unique approach to co-deliver both constituents to the same cell-enhancing vaccine efficacy while minimizing reactogenicity.

Clinical trials for the recombinant zoster vaccine (RZV) demonstrated vaccine efficacy of over 90% in preventing herpes zoster.

In conclusion, data from the current studies demonstrated vaccine efficacy in 60-day-old calves against BVDV-1b and BVDV-2 infection.

This paper discusses how limitations to vaccine accessibility, issues associated with vaccine side effects, concerns regarding vaccine efficacy, along with the persistent prevalence of vaccine hesitancy among the public, including health care professionals, might impact the potential of COVID-19 vaccines to curb the pandemic.

While, viral evolution, concerns regarding vaccine efficacy and side effects, and cost of vaccine ranked as top vaccination barriers.

Conclusion: The current strains analyzed belonged to the G1P[8] rotavirus A genotypes, indicating high coverage of current rotavirus vaccines and affirming the importance of continuous characterization of circulating rotavirus strains and monitoring vaccine efficacy.

As serological testing becomes more commonplace, it is important to establish widespread and repeatable processes for monitoring vaccine efficacy.

After discussing risks and benefits, particularly of potential lowered vaccine efficacy, the patient was prescribed topical steroids and a prednisone taper.

Observing the vast amount of published media images of persons receiving their vaccines, the authors noted in many cases the injection technique involved skin bunching, raising concerns of inadequate deltoid muscle penetration and consequent lowered vaccine efficacy.

Further development of controlled human infection models for rotavirus, especially in prospective studies with larger sample sizes, may be a promising tool to assess rotavirus vaccine efficacy and CoPs.

However, rotavirus vaccine efficacy (VE) appears to wane over the first 2 years since vaccination, particularly in developing countries.

The inclusion of older adult populations in the vaccine trials help to understand how health status and frailty can influence vaccine efficacy, safety, immunogenicity, and reactogenicity in older adults [3].

Age at vaccination, the delivery route, and vaccination protocol can influence vaccine efficacy.

In this study, to enhance DNA vaccine efficacy against Aeromonas infections, a fused DNA fragment (1504 bp) of the OmpAI gene from Aeromonas veronii (A.

Here, we show that by targeting influenza antigens directly to antigen presenting cells (APC), DNA vaccine efficacy equals that of conventional technologies.

Background and aims Two SARS-CoV-2 mRNA vaccines were approved to prevent COVID-19 infection, with reported vaccine efficacy of 95%.

Although protective concentrations of vaccine-induced antibodies are still not formally defined, we evaluated the sustainability of neutralising antibodies in vaccine trial participants 2-12 years after vaccination and the correlation with reported vaccine efficacy.

2 Tuberculin skin test (TST) is applied widely to assess BCG vaccine efficacy and screen latent TB infection.

These include antimycobacterial activity, modulation of the host immune response, and enhancement of BCG vaccine efficacy.

Immune complexes (ICs) made of antibody-bound antigens exhibit immunomodulatory activities exploitable in a vaccination strategy to optimize vaccine efficacy.

Current vaccine formulations are the same for both adults and children, but tailoring these formulations to age category could optimize vaccine efficacy.