Immunogenicity, safety and reactogenicity of a heterogeneous booster following the CoronaVac inactivated SARS-CoV-2 vaccine in patients with SLE: a case series

Since the COVID-19 pandemic, CoronaVac, an inactivated SARS-CoV-2 vaccine, has been widely deployed in several countries for emergency use. However, the immunogenicity of the inactivated vaccine was relatively lower when compared to other vaccine types and was even more attenuated in autoimmune patients with rheumatic disease. A third-dose SARS-CoV-2 vaccination in immunosuppressed population is recommended in order to improve immune response. However, the data were limited to those initially received mRNA or viral vector SARS-CoV-2 vaccine. Thus, we aimed to describe the safety, reactogenicity and immunogenicity of patients with systemic lupus erythematosus (SLE) who received a heterogenous booster SARS-CoV-2 vaccine following the initial CoronaVac inactivated vaccine series. Our findings support that the third booster dose of mRNA or viral vector vaccine following the inactivated vaccine is well tolerated and elicited a substantial humoral and cellular immune response in inactive patients with SLE having maintenance immunosuppressive therapy without interruption of immunosuppressive medications.

Severity of Disease and Outcomes in Vaccinated and Non Vaccinated Covid patients in District Muzaffarabad AJK

Aim: Covid infection after first and second dose of vaccination was assessed in comparison to unvaccinated SARS-CoV-2 infection patients. Methodology: Patients were divided into two groups: those who had not got any immunizations and those who had received vaccines that were prescribed. Individuals who have taken second dose of either the mRNA vaccine or the viral vector vaccine and have a positive COVID-19 within 14 days of receiving their second dose are deemed fully immunised. Results: Among 180 patients, the males were 75% and 25% was females. In our study, 16.7% (30/180) patients still suffered from COVID-19 despite of the fact that they were vaccinated, but the ratio of immune patients was greater i.e. 83.3% (150/180).The severity of the symptoms in vaccinated patients was much lesser and in some cases almost nil. 144/180 (80%) patients did not suffer from any severe symptoms after vaccination. 33/180 (18.3%) patients showed moderate symptoms while 3/180 (1.7%) showed severe symptoms. In the analysis of severity of symptoms of non vaccinated patients, 70% (126/180) showed severe symptoms, 25% (45/180) showed moderate and 5% (9/180) patients showed low symptoms. Conclusion: People without vaccination have more severe symptoms whereas COVID patients with vaccination had a reduced mortality rate and milder symptoms. Keywords: SARS-COV-2, vaccination, without vaccination

Vaccinia Virus: From Crude Smallpox Vaccines to Elaborate Viral Vector Vaccine Design

Various vaccinia virus (VACV) strains were applied during the smallpox vaccination campaign to eradicate the variola virus worldwide. After the eradication of smallpox, VACV gained popularity as a viral vector thanks to increasing innovations in genetic engineering and vaccine technology. Some VACV strains have been extensively used to develop vaccine candidates against various diseases. Modified vaccinia virus Ankara (MVA) is a VACV vaccine strain that offers several advantages for the development of recombinant vaccine candidates. In addition to various host-restriction genes, MVA lacks several immunomodulatory genes of which some have proven to be quite efficient in skewing the immune response in an unfavorable way to control infection in the host. Studies to manipulate these genes aim to optimize the immunogenicity and safety of MVA-based viral vector vaccine candidates. Here we summarize the history and further work with VACV as a vaccine and present in detail the genetic manipulations within the MVA genome to improve its immunogenicity and safety as a viral vector vaccine.

Immunogenicity and adverse events of priming with inactivated whole SARS-CoV-2 vaccine (CoronaVac) followed by boosting the ChAdOx1 nCoV-19 vaccine

Background: Responding to SARS-CoV-2 Delta variants escaped the vaccine-induced immunity and waning immunity from the inactivated whole virus vaccine, Thailand recently proposed a heterologous inactivated whole virus vaccine (CoronaVac) viral vector vaccine (ChAdOx1 nCoV-19) prime-boost vaccine regimen(I/V). This study aims to evaluate the immunogenicity and adverse events of this regimen by comparison with homologous CoronaVac, ChAdOx1 nCoV-19, and convalescent serum. Method: Immunogenicity was evaluated by the level of IgG antibodies against the receptor-binding domain of the SARS-CoV-2 spike protein (S1 subunit) (anti-S RBD). At 2 weeks following the second dosage, a selection of random samples was tested for plaque reduction neutralisation (PRNT) and Pseudotype-Based Microneutralization test (PVNT) against SARS-CoV-2 variants of concern (VOCs). The safety profile of heterologous CoronaVac-ChAdOx1 nCoV-19 prime-boost vaccine regimen was described by interviewing at the 1-month visit. Result: Between April to August 2021,426 participants were included in the study, with 155 obtaining CoronaVac-ChAdOx1 nCoV-19(I/V),32 obtaining homologous CoronaVac(I/I),47 obtaining homologous ChAdOx1 nCoV-19(V/V),169 with history covid-19 infection. Geometric mean titers (GMTs) of anti-S RBD level in the I/V group compare 2wks and 4 wks ( 873.9 vs 639,p=0.00114).At 4 wks, GMTs of anti-S RBD level in I/V group was 639, 95% CI 63-726,and natural infection group 177.3, 95% CI 42-221, and V/V group 211.1, 95% CI 77-152 ,and I/I group 108.2 ,95% CI 77-152 ; all p<0.001).At 2 wks, The GMTs of 50%PRNT of 19 sampling from the I/V group is 434.5, 95% CI 326-579, against wild type and 80.4, 95% CI 56-115, against alpha and 67.4, 95% CI 48-95, against delta and 19.8, 95% CI 14-30, against beta; all p<0.001. At 2 wks, The GMTs of 50%PVNT of 15 sampling from the I/V group is 597.8, 95% CI 368-970, against wild type and 163.9, 95% CI 89-301, against alpha and 157.7, 95% CI 66-378, against delta. The AEs in the I/V schedule were well tolerated and generally unremarkable. Conclusion: The I/V vaccination is a mixed regimen that induced higher immunogenicity and shall be considered for responding to Delta Variants when only inactivated whole virus vaccine and viral vector vaccine was available.

One-shot immunization with Sputnik Light (the first component of Sputnik V vaccine) is effective against SARS-CoV-2 Delta variant: efficacy data on the use of the vaccine in civil circulation in Moscow

Objectives Vaccination remains the most effective response to the COVID-19 pandemic. Most vaccines use two-dose regimens. In turn, single-dose vaccines also have high potential, since, on the one hand, they simplify the vaccination program, make it more accessible and convenient for more people around the world, and on the other hand, they are better suited for subsequent revaccination. However, there is not enough data on the effectiveness of single-dose vaccine variants against new genetic lines to assess their current potential. It is not clear how much a single dose of immunization protects against the globally dominant delta variant. In this work, we investigated the effectiveness of a single dose vaccine (Sputnik Light, the first component of Sputnik V vaccine) against the Delta variant in Moscow. Methods To assess the effectiveness of one dose of viral vector vaccine based on rAd26 against the delta variant in Moscow, we used data from the Moscow registries of vaccination against COVID-19 and the incidence of COVID-19. The availability of data on the number of seropositive residents of Moscow made it possible to consider the size of the immune layer formed because of a previous COVID-19 disease or vaccination. To calculate the effectiveness, the proportion of COVID-19 cases among those vaccinated with a single dose and the proportion of cases among those who were not vaccinated in July 2021. Results Our data indicate that throughout July 2021, the dominant variant of the coronavirus at the level of 99.5% in Moscow was the SARS-CoV-2 delta variant and its subsidiary lines. Considering the immune layer of 46% allowed us to calculate the effectiveness of a one-shot vaccine against the delta variant in Moscow during the first three months after vaccination at the level of 69.85% (95% confidence interval [CI], 64.08 to 74.70). In the 18-29-year-old group, the overall vaccine efficacy against the delta variant was 88.61%, in the 18-59 group - 75.28%. Sputnik Light demonstrates higher efficacy against Delta variant than many two-shot vaccines. Conclusion The results indicate a high efficacy of a single immunization first component of Sputnik V vaccine against delta variant among young and middle-aged people (86.2% and 75.28%, respectively), at least during the first 3 months after receiving the one-shot vaccine.

Combined Hormonal Contraception and the Adenoviral Vector Covid-19 Vaccines

There are at least 4 different types of covid-19 vaccines that are available worldwide. The most widely used ones are the mRNA genetic vaccine and the viral vector vaccine. In the midst of the COVID-19 pandemic and after the administration of millions of those vaccines globally over few months, several national health authorities across Europe decided to pause the administration of the chimpanzee adenovirus-vectored vaccine1 (ChAdOx1nCoV-19, AZD1222; Oxford/AstraZeneca) after sporadic reports of severe cases of thrombocytopenia, bleeding, or thrombosis in those who received this vaccine. This complication has been identified as Vaccine-Induced Immune Thrombotic Thrombocytopenia (VITT) that affects mostly woman under the age of 55 years at a rate of 1:100,000 vaccine doses. Combined hormonal contraceptives (CHC) are known to carry the risk of thrombosis in certain high-risk population. Accordingly, women taking those contraceptives raised their concern of getting such vaccine. This review will attempt to explain the different mechanisms of thrombosis which abolish any link between the VITT complication and the use of CHC. Reassuring statements from authoritative agencies are also included.

Negative results of humoral immunity after anti-SARS-CoV-2 vaccination in patient with advanced ovarian cancer treated with maintenance immunotherapy and targeted therapy: a clinical case and а literature review

Gam-COVID-Vac (Sputnik V, Gamaleya Research Institute of Epidemiology and Microbiology of Ministry of Health of Russian Federation) is an adenovirus viral vector vaccine for COVID-19 which became the very first vaccine against SARS-CoV-2 registered in Russia and worldwide. The vaccine efficacy and safety in cancer patients is unknown. We present a clinical case of the absence of post-vaccination immunity after the use of Gam-COVID-Vac in a patient with advanced ovarian cancer treated with maintenance targeted and immunotherapy and discuss it in the light of the available evidence base on the effectiveness of other anti-SARS CoV-2 vaccines in cancer patients.

Developmental Landscape of Potential Vaccine Candidates Based on Viral Vector for Prophylaxis of COVID-19

Severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, arose at the end of 2019 as a zoonotic virus, which is the causative agent of the novel coronavirus outbreak COVID-19. Without any clear indications of abatement, the disease has become a major healthcare threat across the globe, owing to prolonged incubation period, high prevalence, and absence of existing drugs or vaccines. Development of COVID-19 vaccine is being considered as the most efficient strategy to curtail the ongoing pandemic. Following publication of genetic sequence of SARS-CoV-2, globally extensive research and development work has been in progress to develop a vaccine against the disease. The use of genetic engineering, recombinant technologies, and other computational tools has led to the expansion of several promising vaccine candidates. The range of technology platforms being evaluated, including virus-like particles, peptides, nucleic acid (DNA and RNA), recombinant proteins, inactivated virus, live attenuated viruses, and viral vectors (replicating and non-replicating) approaches, are striking features of the vaccine development strategies. Viral vectors, the next-generation vaccine platforms, provide a convenient method for delivering vaccine antigens into the host cell to induce antigenic proteins which can be tailored to arouse an assortment of immune responses, as evident from the success of smallpox vaccine and Ervebo vaccine against Ebola virus. As per the World Health Organization, till January 22, 2021, 14 viral vector vaccine candidates are under clinical development including 10 nonreplicating and four replicating types. Moreover, another 39 candidates based on viral vector platform are under preclinical evaluation. This review will outline the current developmental landscape and discuss issues that remain critical to the success or failure of viral vector vaccine candidates against COVID-19.

Ad26.COV2.S viral vector vaccine’s safety and immunogenicity: A review of literature

COVID-19 is a respiratory infectious disease that spreads through droplets. This disease has brought immense changes that impacted all countries around the world and the healthcare system in many ways. Developing an effective vaccine has been a high priority and clinical trials are continuously conducted to improve their efficacy. There are two current competing forms of the vaccine: the first is mRNA vaccines, where they act as a carrier for immunological information encoding for the antigen (spike proteins) and induce an immune response without interacting with the genome. Although they have an effectiveness of 95%, they do require two doses to be fully effective. On the other hand, viral vector-based vaccines use a vector to deliver the genetic code for the antigen and, like a normal infection, uses the body cell’s machinery to produce more antigen, triggering an immune response. Many clinical trials are being done to improve and evaluate its efficacy as this vaccine provides substantial potential advantages, one of which includes requiring only one dosage to be vaccinated to reach greater effectiveness in inducing antibody and CD4 T cells production. In consideration of the WHO SAGE Roadmap for vaccine prioritization, the aim of this study is to provide a review of the current literature and clinical trials being conducted on the viral vector vaccine Ad26.COV2.S’s safety and immunogenicity. In addition, it assesses potential future directions, implications and the substantial benefits towards the health care system and at-high-risk populations.