Effectiveness of the CoronaVac® vaccine in a region of the Colombian Amazon, was herd immunity achieved?

Introduction Currently, more than 4.5 billion doses of SARS-CoV-2 vaccines have been applied worldwide. However, some developing countries are still a long way from achieving herd immunity through vaccination. In some territories, such as the Colombian Amazon, mass immunization strategies have been implemented with the CoronaVac® vaccine. Due to its proximity to Brazil, where one of the variants of interest of SARS-CoV-2 circulates. Objective To determine the effectiveness of the CoronaVac® vaccine in a population of the Colombian Amazon. Methods Between February 24, 2021, and August 10, 2021, a descriptive observational study was carried out in which a population of individuals over 18 years of age immunized with two doses of the CoronaVac® vaccine was evaluated. The study site was in the municipality of Mitú, Vaupés, in southeastern Colombia, a region located in the Amazon bordering Brazil. Results. 99% of the urban population of the Mitú municipality were vaccinated with CoronaVac®. To date, 5.7% of vaccinated individuals have become ill, and only 0.1% of these require hospitalization. One death was attributable to COVID-19 has been reported among vaccinated individuals, and the vaccine has shown 94.3% effectiveness against mild disease and 99.9% against severe infection. Conclusions The herd immunity achieved through mass vaccination in this population has made it possible to reduce the rate of complicated cases and mortality from COVID-19 in this region of the Colombian Amazon. Highlights CoronaVac® has shown 94.3% effectiveness against mild disease and 99.9% against severe infection in this indigenous population. CoronaVac® reduces the mortality rate from 2.2% in 2020 to 0.22% in 2021. The herd immunity was achieved through mass vaccination in this region of the Colombian Amazon.

Exit strategy of COVID-19 crisis and pathways of Vaccination

There is a strong coordinated effort by vaccination groups all over the world to put an end to the current crisis of COVID-19. The Mass vaccination first started in the UK on 8th December 2020 and soon afterward covered all of the globe. Now sufficient data are available to analyse and compare some results to explore many aftereffects of vaccination. Some influence variables on transmissions of the disease were discussed e.g., mass vaccination, lockdown and seasonality. To address seasonality, similarities between COVID-19 and seasonal Flu are discussed to gain useful insight. Like Flu, seasonality was shown to play a dominant role in transmissions of COVID-19 in the Eu-rope and US. In terms of mass vaccination, adverse reactions after vaccination received attention, as health and safety issues of the general public are of prime importance. Apart from direct side effects, the secondary effect of mass vaccination needs attention too. After the initiation of vaccination programme , almost all countries experienced a sudden surge of transmission and most countries had to impose strict lockdown measures. Many countries, those showed a low prevalence of the disease, suddenly showed a steep jump after the onset of mass vaccination. Some countries even followed a synchronized pattern between the rate of transmissions and the variation of vaccine doses; the pattern seemed distinct with the sudden steep rise/fall in vaccine doses (e.g., countries India, Indonesia among others). In that context, fast mutation of the virus and new variants after mass vaccination and possible mechanisms/consequences were discussed. Balanced discussion, critical and open analyses are desperately needed in the current crucial stage. Debating, questioning and criticism are always the foundation of good science and the main pillars to its progress. Following that objective, it is an effort to explore pragmatically, areas relating to the effectiveness of the COVID-19 vaccine and the exit strategy via the pathway of vaccination. Policymakers, academics, patients and common people will be greatly benefitted from such critical, transparent and balanced analyses.

Incidence and Risk Factors of Immediate Hypersensitivity Reactions and Immunisation Stress-related Responses with COVID-19 mRNA Vaccine

Background: With the implementation of mass vaccination campaigns against COVID 19, the safety of vaccine needs to be evaluated. Objective: We aimed to assess the incidence and risk factors for immediate hypersensitivity reactions (IHSR) and immunisation stress related responses (ISRR) with the Moderna COVID 19 vaccine. Methods: This nested case control study included recipients who received the Moderna vaccine at a mass vaccination centre, Japan. Recipients with IHSR and ISRR were designated as cases 1 and 2, respectively. Controls 1 and 2 were selected from recipients without IHSR or ISRR and matched (1:4) with cases 1 and cases 2, respectively. Conditional logistic regression analysis was used to identify risk factors associated with IHSR and ISRR. Results: Of the 614,151 vaccine recipients who received 1,201,688 vaccine doses, 306 recipients (cases 1) and 2,478 recipients (cases 2) showed 318 events of IHSR and 2,558 events of ISRR, respectively. The incidence rates per million doses were estimated as IHSR: 266 cases, ISRR: 2,129 cases, anaphylaxis: 2 cases, and vasovagal syncope: 72 cases. Risk factors associated with IHSR included female, asthma, atopic dermatitis, thyroid diseases, and history of allergy; for ISRR, they were younger age, female, asthma, thyroid diseases, mental disorders, and a history of allergy and vasovagal reflex. Conclusion: In the mass vaccination settings, the Moderna vaccine can be used safely owing to the low incidence rates of IHSR and anaphylaxis. However, providers should beware of the occurrence of ISRR. Risk factor identification may contribute to the stratification of high risk recipients for IHSR and ISRR.

Immunization Stress-Related Responses: Mitigating Patient Fears and Associated Side Effects Amidst a Global Vaccination Effort

The event of receiving a vaccine can lead to feelings of stress and anxiety for many patients and may present as adverse events. With coronavirus disease 2019 (COVID-19) mass vaccination efforts, adverse events following immunization, including immunization stress-related reactions (ISRR), have subsequently increased. Traditionally rare, but increasingly common, cluster events have also become a concern. Demonstrated in recent publications by Hause et al. concerning Janssen (Johnson & Johnson) COVID-19 vaccine clinics, these adverse events can lead to personal apprehension towards receiving vaccines, as well as public distrust towards the immunization process. To combat ISRRs, mass vaccination clinics across the United States must create administration protocols to mitigate these responses. Anticipation and swift management can play a substantial role in minimizing frequency and severity of these reactions and prevent future vaccine hesitancy.

Assessment of COVID-19 Fear in Five European Countries before Mass Vaccination and Key Predictors among Nurses and Nursing Students

Background: Levels of fear have increased since the COVID-19 pandemic outbreak. The absence of a safe and effective vaccine for mass-vaccination deteriorates this situation, which has a significant impact on mental health. This study aimed to assess the feelings of fear among nurses and nursing students in five European countries. Methods: A multicenter cross-sectional study was conducted in five European countries (Greece, Albania, Cyprus, Spain, and Kosovo) before the start of mass vaccination in Europe. Data collection was conducted in December 2020–January 2021 using an online questionnaire for nursing students and professional nurses. Fear of COVID-19 Scale (FCV-19S) was used for measuring levels of fear. IBM SPSS version 21.0 was used for statistical analysis. Results: The study population included 1135 nurses and 1920 nursing students from Kosovo (n = 1085), Spain (n = 663), Greece (n = 534), Albania (n = 529), and Cyprus (n = 244). According to multivariable analysis, females (OR = 2.53, 95% CI = 1.89–3.15), married (OR = 0.86, 95% CI = 0.24–1.48), nurses (OR = 0.87, 95% CI = 0.28–1.45) and those with a chronic disease (OR = 0.86, 95% CI = 0.11–1.62) were more fearful of COVID-19. Conclusions: It is important to decrease fear in the population of nurses who are at the frontlines of the pandemic. The provision of appropriate education and training activities for nurses and students to manage their stress levels is of high importance. Future studies should focus on levels of fear after the administration of several safe and effective vaccines worldwide.

Immune Maturation Effects on Viral Neutralization and Avidity of Hyperimmunized Equine Anti-SARS-CoV-2 Sera

Mass-vaccination against COVID-19 is still a distant goal for most low-to-middle income countries. The experience gained through decades producing polyclonal immunotherapeutics (such as antivenoms) in many of those countries is being redirected to develop similar products able to neutralize SARS-CoV-2 infection. In this study we analyzed the biological activity (viral neutralization or NtAb) and immunochemical properties of hyperimmune horses’ sera (HHS) obtained during initial immunization (I) and posterior re-immunization (R) cycles using the RBD domain of the SARS-CoV-2 spike protein as antigen. HHS at the end of the R cycle showed higher NtAb titers when compared to those after the I cycle (35,585 vs. 7000 mean NtAb, respectively). Moreover, this increase paralleled an increase in avidity (95.2% to 65.2% mean avidity units, respectively). The results presented herein are relevant for manufacturers of these therapeutic tools against COVID-19.