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Author(s):  
Cezar Morar ◽  
Alexandru Tiba ◽  
Tamara Jovanovic ◽  
Aleksandar Valjarević ◽  
Matthias Ripp ◽  
...  

The persistence of the SARS-CoV-2 virus imposed vaccination passports for traveling in most countries. We investigated psychological factors that predict the intention to vaccinate for travel. In a cross-sectional study, we examined how demographic variables, vaccination status, perceived risk of infection and severity of disease contracted at travel destination, safety and effectiveness of vaccines against contracting COVID-19 during travel, and conspiracy beliefs are related to intention to vaccinate for travel. Further analyses involved differences between vaccinated and unvaccinated individuals in a Romanian sample regarding conspiracy beliefs, attitudes about vaccines, and self-efficacy of controlling COVID-19 infection. Results showed that the intention to vaccinate for travel reasons is best predicted by vaccination status and perceptions of safety and efficacy of vaccines against COVID-19. Thus, vaccinated individuals believing that vaccines are safe and effective most probably will take another vaccine booster if it will allow them to travel. Positive relationships of the intention to vaccinate for travel reasons were found with age, vaccination status, conspiracy beliefs, perceptions of safety and effectiveness of vaccines, intention to travel, and a more cautious approach to travel. No significant relationships were found between perceptions of risk for self or for transmitting the disease to others, severity of disease, and the intention to vaccinate for travel. We also found significant differences between vaccinated and unvaccinated participants, as unvaccinated participants showed higher levels of conspiracy beliefs and less trust in the safety and efficacy of vaccines. We conclude that campaigns focused on promoting information on the safety and efficacy of vaccines is the most important direction for promoting vaccination in young travelers.


2022 ◽  
Author(s):  
Andrea T. Nguyen ◽  
Christopher Szeto ◽  
Demetra S.M. Chatzileontiadou ◽  
Zhen Wei Marcus Tong ◽  
Michael J. Dewar-Oldis ◽  
...  

The >30 mutated residues in the Omicron spike protein have led to its rapid classification as a new SARS-CoV-2 variant of concern. As a result, Omicron may escape from the immune system, decreasing the protection provided by COVID-19 vaccines. Preliminary data shows a weaker neutralizing antibody response to Omicron compared to the ancestral SARS-CoV-2 virus, which can be increased after a booster vaccine. Here, we report that CD8+ T cells can recognize Omicron variant epitopes presented by HLA-A*02:01 in both COVID-19 recovered and vaccinated individuals, even 6 months after infection or vaccination. Additionally, the T cell response was stronger for Omicron variant epitopes after the vaccine booster. Altogether, T cells can recognize Omicron variants, especially in vaccinated individuals after the vaccine booster.


2022 ◽  
Vol 9 ◽  
Author(s):  
Rui Li ◽  
Yan Li ◽  
Zhuoru Zou ◽  
Yiming Liu ◽  
Xinghui Li ◽  
...  

Background: Multiple SARS-CoV-2 variants are still rampant across the United States (US). We aimed to evaluate the impact of vaccination scale-up and potential reduction in the vaccination effectiveness on the COVID-19 epidemic and social restoration in the US.Methods: We extended a published compartmental model and calibrated the model to the latest US COVID-19 data. We estimated the vaccine effectiveness against the variant and evaluated the impact of a potential reduction in vaccine effectiveness on the epidemics. We explored the epidemic trends under different levels of social restoration.Results: We estimated the overall existing vaccine effectiveness against the variant as 88.5% (95% CI: 87.4–89.5%) with the vaccination coverage of 70% by the end of August, 2021. With this vaccine effectiveness and coverage, there would be 498,972 (109,998–885,947) cumulative infections and 15,443 (3,828–27,057) deaths nationwide over the next 12 months, of which 95.0% infections and 93.3% deaths were caused by the variant. Complete social restoration at 60, 65, 70% vaccination coverage would increase cumulative infections to 1.6 (0.2–2.9) million 0.7 (0.1–1.2) million, and 511,159 (110,578–911,740), respectively. At same time it would increase cumulative deaths to 39,040 (5,509–72,570), 19,562 (3,873–35,250), 15,739 (3,841–27,638), respectively. However, if the vaccine effectiveness were reduced to 75%, 50% or 25% due to new SARS-CoV-2 variants, there would be 667,075 (130,682–1,203,468), 1.7 (0.2–3.2) million, 19.0 (5.3–32.7) million new infections and 19,249 (4,281–34,217), 42,265 (5,081–79,448), 426,860 (117,229–736,490) cumulative deaths to occur over the next 12 months. Further, social restoration at a lower vaccination coverage would lead to even greater secondary outbreaks.Conclusion: Current COVID-19 vaccines remain effective against the SARS-CoV-2 variant, and 70% vaccination coverage would be sufficient to restore social activities to a pre-pandemic level. Further reduction in vaccine effectiveness against SARS-CoV-2 variants would result in a potential surge of the epidemic. Multiple measures, including public health interventions, vaccination scale-up and development of a new vaccine booster, should be integrated to counter the new challenges of new SARS-CoV-2 variants.


2022 ◽  
Author(s):  
Camilla Mattiuzzi ◽  
Giuseppe Lippi

Abstract Background: We provide here an analysis of effectiveness of primary coronavirus disease 2019 (COVID-19) vaccination and COVID-19 vaccine booster doses in preventing severe acute respiratory syndrome coronavirus 2 (COVID-19) infection.Methods: We retrieved information on COVID-19 vaccination and newly diagnosed cases of SARS-CoV-2 infection from the weekly official report of the Italian National Institute of Health (Istituto Superiore di Sanità, ISS; Last available update, January 1, 2022).Results: At the time of our analysis, 39.9 million people completed a primary COVID-19 vaccination cycle, of whom 13.6 million (34.0%) <5 months from the last dose, whilst 5.7 million had also received COVID-19 vaccine booster doses. The risk of SARS-CoV-2 infection was 71% (OR, 0.29; 95%CI, 0.29-0.29) and 86% (OR, 0.14; 95%CI, 0.14-0.14) lower in people who received primary vaccination <5 months and booster doses <5 months compared to the unvaccinated population, but was also half (OR, 0.49; 95%CI, 0.48-0.49) in those who received booster doses <5 months compared to those who completed the primary vaccination <5 months.Conclusions: These results attest that COVID-19 vaccines not only reduce the risk of developing severe illness in patients with SARS-CoV-2 infection, but shall also be considered reliable and effective means to limit virus circulation within the general population.


Vaccines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 68
Author(s):  
Mateusz Babicki ◽  
Agnieszka Mastalerz-Migas

Introduction: COVID-19 vaccination has now become the most effective way to combat the pandemic, but there is a gradual decline in the protection that it offers over time. Therefore, the Food and Drug Administration (FDA) and EMA now recommend the use of the so-called booster dose, especially in at-risk groups. The purpose of the study was to assess the attitudes of Poles towards the recommendation to receive a booster dose of the COVID-19 vaccine and to evaluate the main reasons for refusing or delaying the decision. Material and methods: The study was based on a proprietary questionnaire distributed via the Internet. There were 1598 respondents, 54 of which did not consent to participate in the survey and/or did not complete the vaccination against SARS-CoV-2. As a result, 1528 surveys were included in the final analysis. The vast majority of the respondents, namely 1275 (83.4%), were female, and 772 (50.5%) were residents of cities with a population of over 250,000. Results: Out of all respondents, 38 (2.5%) had already received the COVID-19 vaccine booster dose and 1031 (67.4%) would like to receive it as soon as possible. Forty-five (2.9%) respondents reported that they were completely unwilling to take the booster dose. The occurrence of adverse events after primary vaccination were reported by 79.9% of the survey participants. The most common reasons why the respondents refused to be vaccinated are lack of confidence in the effectiveness of the booster dose and the occurrence of adverse events in them or their loved ones. Age, gender, residence, or relationship status were not shown to affect attitudes towards the expansion of the basic vaccination schedule. Conclusions: One in three respondents plans to delay or refrain from taking the COVID-19 vaccine booster dose. The main reason for refusal to be vaccinated is the belief that the previous vaccination provides sufficient protection.


2022 ◽  
Author(s):  
Monica Taminato ◽  
Ana Paula Cunha Chaves ◽  
Richarlisson Borges de Morais ◽  
Luiz Vinícius Leão Moreira ◽  
Danielle Dias Conte ◽  
...  

Background Health Care workers (HCW) are an important group affected by this pandemic and COVID-19 has presented substantial challenges for health professionals and health systems in many countries. The Brazilian vaccination plan implemented in October, so that third dose for HCW. However, the persistence of CoronaVac vaccine-induced immunity is unknown, and immunogenicity according to age cohorts may differ among individuals. Objective Evaluate the post vaccination immune humoral response and the relationship between post-vaccination seropositivity rates and demographic data among Healthcare Workers over 6 months after CoronaVac immunization. Methods A cross section study including Healthcare professionals vaccinated with CoronaVac for 6 months or more. The study was carried with the analysis of post-vaccination serological test to assess the levels of humoral response after vaccination. Results 329 participants were included. Among them, 76% were female. Overall, 18.5% were positive quantitative titles (IQR 42.87-125.5) and the negative group was 80%, quantitative titles (IQR 5.50-13.92). Conclusion It was possible to identify a group with positive quantitative titles in serological test for IgG antibody against the SARS-CoV-2. Further investigation is required to determine the durability of post-vaccination antibodies and how serological tests can be determine the ideal timing of vaccine booster doses.


2021 ◽  
Author(s):  
Glenda E Gray ◽  
Shirley COLLIE ◽  
Nigel Garrett ◽  
Ameena Goga ◽  
Jared Champion ◽  
...  

Following the results of the ENSEMBLE 2 study, which demonstrated improved vaccine efficacy of a two-dose regimen of Ad26.COV.2 vaccine given 2 months apart, we expanded the Sisonke study which had provided single dose Ad26.COV.2 vaccine to almost 500 000 health care workers (HCW) in South Africa to include a booster dose of the Ad26.COV.2. Sisonke 2 enrolled 227 310 HCW from the 8 November to the 17 December 2021. Enrolment commenced before the onset of the Omicron driven fourth wave in South Africa affording us an opportunity to evaluate early VE in preventing hospital admissions of a homologous boost of the Ad26.COV.2 vaccine given 6-9 months after the initial vaccination in HCW. We estimated vaccine effectiveness (VE) of the Ad26.COV2.S vaccine booster in 69 092 HCW as compared to unvaccinated individuals enrolled in the same managed care organization using a test negative design. We compared VE against COVID19 admission for omicron during the period 15 November to 20 December 2021. After adjusting for confounders, we observed that VE for hospitalisation increased over time since booster dose, from 63% (95%CI 31-81%); to 84% (95% CI 67-92%) and then 85% (95% CI: 54-95%), 0-13 days, 14-27 days, and 1-2 months post-boost. We provide the first evidence of the effectiveness of a homologous Ad26.COV.2 vaccine boost given 6-9 months after the initial single vaccination series during a period of omicron variant circulation. This data is important given the increased reliance on the Ad26.COV.2 vaccine in Africa.


2021 ◽  
Author(s):  
Giuseppe Lippi ◽  
Camilla Mattiuzzi ◽  
Brandon M. Henry

Abstract Background: We carried out a literature search for summarizing currently published evidence on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (B.1.1.529) variant neutralizing properties of serum or plasma collected from recipients of coronavirus disease 2019 (COVID-19) vaccines.Methods: An electronic search was conducted in Medline and Scopus, using the keywords “vaccine” AND “Omicron” OR “B.1.1.529” AND “SARS-CoV-2” AND “neutralization” OR “antibodies”, with no language or date limits (i.e., up to December 27, 2021). Studies with complete information on neutralization properties of COVID-19 vaccines against the Omicron variant, with or without the adjunctive effects of booster vaccine doses, were included.Results: Our final analysis included 10 published studies. In all, decreased neutralisation of SARS-CoV-2 Omicron B.1.1.529 variant was evidenced in post-vaccination samples, ranging between -4.3 folds to absence of neutralization compared to an ancestral SARS-CoV-2 strain. In all studies the COVID-19 vaccine booster dose was effective to elicit sustained enhancement of SARS-CoV-2 Omicron B.1.1.529 neutralisation, with such increase being comprised between 10-42 folds compared to the pre-booster period.Conclusion: Vaccine boosters seem strongly advisable for limiting the risk of SARS-CoV-2 Omicron (B.1.1.529) breakthrough infections.


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