Safety and Immunogenicity Outcomes of an Inactivated Viral Vaccine against SARS-CoV-2 (Covaxin)

Introduction: Bharat Biotech International Ltd in partnership with National Institute of Virology (NIV), has developed an indigenous whole virion inactivated Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) viral vaccine BBV-152 (Covaxin), formulated with Toll Like Receptors 7/8 agonist Imidazoquinoline (IMDG) molecule adsorbed to alum (Algel). Variety of factors other than environmental ones can affect vaccines efficiency outside the strict setting of clinical trials, like how the vaccine is stored or transported, and even how patients are vaccinated. In addition, the intrinsic capacity of the recipient to respond to a vaccine which is determined by sex, genetic factors, age, psychological stress, nutrition and other diseases are also likely to have an impact. Aim(s): To determine the safety, reactogenicity and immunogenicity of the inactivated whole virus vaccine (Covaxin) amongst hospital-based population groups. Material(s) and Method(s): The prospective analytical study was conducted in the Department of Microbiology, Sawai Man Singh Medical College, Jaipur, Rajasthan, India, from January 2021 to March 2021.The study primarily included Healthcare Workers (HCWs) employed at SMS Medical college and attached hospitals. In-vitro quantitative IgG antibodies against SARS-CoV-2 spike Receptor Binding Domain (RBD) were measured using Chemiluminescence Immunoassay (CLIA) based Advia centaur SARS-CoV-2 IgG, manufactured by Siemens Pvt Ltd, Munich, Germany, as per manufacture's instructions. Result(s): Out of total 223 individuals, 61.88 % (138/223) showed neutralising antibody titre of >1 index value by CLIA, rest 38.12% (85/223) were non reactive i.e., titre <1 index value, after four weeks of receiving first dose of Covaxin. After 2 to 4 weeks of receiving second dose 84.30% (188/223) showed neutralising antibody titre of >1 index value by CLIA, rest 15.70% (35/223) were non reactive i.e., titre <1 index value. After receiving first dose, 100% (223/223) of the participants developed localised pain and bodyache 33.63% (75/223). None of the participants showed any anaphylactic reaction or any emergency condition just after vaccination. Conclusion(s): Covaxin is a well-tolerated vaccine, and induces good humoral response against SARS-CoV-2 with a significant rise in the neutralising antibody titres. Copyright © 2022 Journal of Clinical and Diagnostic Research. All rights reserved.

Neutralizing IgG antibody seroprevalence, efficacy and safety post covishield vaccination: A follow up study

COVID-19, a pandemic caused by severe acute respiratory syndrome (SARS) corona virus-2 has been a worldwide challenge for the entire mankind. However, a safe and efficacious vaccine would be clinically valuable to reduce the risks of COVID-19. In this study, we aimed to assess the seroprevalence of the Neutralizing IgG Antibodies six months after completion of both the doses of Covishield Vaccination (ChAdox1 nCoV-19) and compare it with the IgG titres one month after the first dose and one month after the second dose of the vaccine respectively. The efficacy, safety and comorbidities related to the vaccine were also assessed at different time intervals. The levels of IgG antibodies were estimated in 72 subjects from the Teerthanker Mahaveer Medical College & Research Centre (who turned up after six months of the complete regimen of Covishield Vaccination) using the Enzyme-Linked Immunosorbent Assay (ELISA) Technique. A highly significant increase (p= 0.00) in the neutralizing Antibodies titre was seen in fully vaccinated individuals post six months when compared to the titres of post one month of 1st & 2nddoses. It can therefore be concluded that (ChAdox1 nCoV-19) Covishield Vaccination if administered in full regimen has both acceptable efficacies as well as safety profile. Hence, a complete vaccine regimen may prove as an effective strategy against COVID-19 and consequent minimization of long-term morbid effects. © 2022 International Journal of Health Sciences.

At Least Three Doses of Leading Vaccines Essential for Neutralisation of SARS-CoV-2 Omicron Variant.

Plasma samples taken at different time points from donors who received either AstraZeneca (Vaxzevria) or Pfizer (Comirnaty) or Moderna (Spikevax) coronavirus disease-19 (COVID-19) vaccine were assessed in virus neutralization assays against Delta and Omicron variants of concern and a reference isolate (VIC31). With the Pfizer vaccine there was 6-8-fold reduction in 50% neutralizing antibody titres (NT50) against Delta and VIC31 at 6 months compared to 2 weeks after the second dose; followed by 25-fold increase at 2 weeks after the third dose. Neutralisation of Omicron was only consistently observed 2 weeks after the third dose, with most samples having titres below the limit of detection at earlier timepoints. Moderna results were similar to Pfizer at 2 weeks after the second dose, while the titres for AstraZeneca samples derived from older donors were 7-fold lower against VIC31 and below the limit of detection against Delta and Omicron. Age and gender were not found to significantly impact our results. These findings indicate that vaccine matching may be needed, and that at least a third dose of these vaccines is necessary to generate sufficient neutralising antibodies against emerging variants of concern, especially Omicron, amidst the challenges of ensuring vaccine equity worldwide.

Norovirus outbreak amid COVID-19 in the United Kingdom; priorities for achieving control.

Norovirus, an enteric virus primarily responsible for gastroenteritis outbreaks worldwide, is currently causing outbreaks around the United Kingdom during the COVID-19 pandemic. With an already exhausted health care system, the significant burden norovirus can have on the National Health Service, including economic and social burdens, is immense and cannot be tolerated. Primary challenges and priorities to be focused on due to the increase in norovirus outbreaks include a further depletion of health care services, increase cases in schools, nurseries, and care facilities, underreporting of the cases, and no effective vaccine being available. Therefore, it is essential to increase awareness about norovirus and its transmission in public, take necessary precautions, and increase reporting of cases. This article discusses the impact norovirus has during the COVID-19 pandemic, and the challenges, and recommendations to achieve control before it reaches epidemic levels.

Earlier In Vitro Viral Production With SARS-CoV-2 Alpha Than With Beta, Gamma, B, or A.27 Variants.

Since its emergence in China at the end of 2019, SARS-CoV-2 has rapidly spread across the world to become a global public health emergency. Since then, the pandemic has evolved with the large worldwide emergence of new variants, such as the Alpha (B.1.1.7 variant), Beta (B.1.351 variant), and Gamma (P.1 variant), and some other under investigation such as the A.27 in France. Many studies are focusing on antibody neutralisation changes according to the spike mutations, but to date, little is known regarding their respective replication capacities. In this work, we demonstrate that the Alpha variant provides an earlier replication in vitro, on Vero E6 and A549 cells, than Beta, Gamma, A.27, and historical lineages. This earlier replication was associated with higher infectious titres in cell-culture supernatants, in line with the higher viral loads observed among Alpha-infected patients. Interestingly, Beta and Gamma variants presented similar kinetic and viral load than the other non-Alpha-tested variants.