Durability of antibodies post vaccination with two doses of inactivated BBIBP-CorV vaccine.

BACKGROUND: Breakthrough infections post-COVID-19 vaccination occur with the emerging variants of the SARS-CoV virus which might be either due to the newer variants escaping immune response or the waning of antibodies over time. However, there is lack of long-term follow-up evidence on the waning of immune response following inactivated COVID-19 vaccine. METHODS: A retrospective, observational study was conducted on serum samples of individuals who had received two doses of BBIBP-CorV vaccine. Individual's antibody responses were evaluated based on IgG anti-S and neutralizing antibodies measurements. Antibody samples were categorized into four groups, defined by the time interval from the individual's receipt of the BBIBP-CorV vaccine: <30 days, 30-90 days, 91-180 days and >180 days. RESULTS: A total of 6668 serum samples from inactivated BBIBP-CorV vaccine recipients were analyzed for IgG anti-S and neutralizing antibodies. 571 (8.6%) samples were tested during the first 29 days interval post vaccination, 3642 (54.6%) were tested during 30-90 days interval, 2173 (32.6%) samples were tested during 91 to 180 days interval and 282(4.2%) were tested at >180 days interval post vaccination. We found that more than 50% of the individuals had antibody titers below the average cut-off range at the 91-180 days interval post vaccination. Older age (>60 years), male gender, chronic kidney disease, hypertension, immunodeficiencies and increased interval post vaccination emerged as independent risk factors associated with lower immune response. CONCLUSION: Inactivated BBIBP-CorV vaccine recipients, based on age, gender and associated comorbid conditions might need booster doses at an earlier interval than the currently followed six months interval.

Effectiveness of BBIBP-CorV vaccine against severe outcomes of COVID-19 in Abu Dhabi, United Arab Emirates.

The effectiveness of the inactivated BBIBP-CorV vaccine against severe COVID-19 outcomes (hospitalization, critical care admission and death due to COVID-19) and its long-term effectiveness have not been well characterized among the general population. We conducted a retrospective cohort study using electronic health records of 3,147,869 adults, of which 1,099,886 vaccinated individuals were matched, in a 1:1 ratio to 1,099,886 unvaccinated persons. A Cox-proportional hazard model with time varying coefficients was used to assess the vaccine effectiveness adjusting for age, sex, comorbidity, ethnicity, and the calendar month of entry into the study. Our analysis showed that the effectiveness was 79.6% (95% CI, 77.7 to 81.3) against hospitalization, 86% (95% CI, 82.2 to 89.0) against critical care admission, and 84.1% (95% CI, 70.8 to 91.3) against death due to COVID-19. The effectiveness against these severe outcomes declined over time indicating the need for booster doses to increase protection against severe COVID-19 outcomes.

Vaccine Side Effects Following COVID-19 Vaccination Among the Residents of the UAE-An Observational Study.

COVID-19 vaccines have proven to be very safe in the clinical trials, however, there is less evidence comparing the safety of these vaccines in real-world settings. Therefore, we aim to investigate the nature and severity of the adverse effects reported and the differences based on the type of vaccine received. A survey was conducted among 1,878 adult (≥18 years) COVID-19 vaccine recipients through online survey platforms and telephonic interviews during March to September 2021. The factors potentially associated with the reported side effects like age, gender, ethnicity, comorbidities, and previous COVID-19 infection were analyzed based on the type of vaccine received. Differences in adverse events and the severity were compared between inactivated and mRNA vaccine recipients. The major adverse effects reported by the COVID-19 vaccine recipients were pain at the site of injection, fatigue and drowsiness, and headache followed by joint/muscle pain. The adverse effects were more common among recipients of mRNA Pfizer-BioNTech vaccine than among recipients of inactive Sinopharm vaccine with the odds ratio of 1.39 (95% CI 1.14-1.68). The average number of adverse effects reported between individuals who had received Sinopharm and Pfizer-BioNTech vaccines was 1.61 ± 2.08 and 2.20 ± 2.58, respectively, and the difference was statistically significant (p <0.001). Severe adverse effects after COVID-19 vaccinations were rare and 95% of the adverse effects reported after either an inactivated or mRNA vaccine were mild requiring no or home-based treatment. The study found that individuals less than 55 years of age, female gender, with history of one or more comorbid conditions, who had received mRNA Pfizer- BioNTech vaccine, and with history of COVID-19 infections are at higher odds of developing an adverse effect post COVID-19 vaccination compared to the others.

The incidence of COVID-19 infection following emergency use authorization of BBIBP-CORV inactivated vaccine in frontline workers in the United Arab Emirates.

Based on the findings from the Phase III clinical trials of inactivated SARS COV-2 Vaccine, (BBIBP-CORV) emergency use authorization (EUA) was granted for the vaccine to frontline workers in the UAE. A prospective cohort study was conducted among frontline workers to estimate the incidence rate and risk of symptomatic COVID-19 infection 14 days after the second dose of inoculation with BBIBP-CORV inactivated vaccine. Those who received two doses of the BBIBP-CORV vaccine in the period from 14th of September 2020 (first dose) to 21st of December 2020 (second dose) were followed up for COVID-19 infections. 11,322 individuals who received the two-dose BBIBP-CORV vaccine were included and were followed up post the second dose plus fourteen days. The incidence rate of symptomatic infection was 0.08 per 1000-person days (95% CI 0.07, 0.10). The estimated absolute risk of developing symptomatic infection was 0.97% (95% CI 0.77%, 1.17%). The confirmed seroconversion rate was 92.8%. There were no serious adverse events reported and no individuals suffered from severe disease. Our findings show that vaccinated individuals are likely to remain protected against symptomatic infection or becoming PCR positive for SARS COV 2 following the second dose of the vaccination.

Immune response of booster doses of BBIBP-CORV vaccines against the variants of concern of SARS-CoV-2.

BACKGROUND: Booster doses for COVID-19 vaccinations are currently recommended and approved in many countries. However, we need more evidence on the immune response of individuals to booster doses of inactivated vaccines and the neutralizing effect against the variants of concerns of SARS-CoV-2. OBJECTIVE: To compare the fold reduction in antibody titers against the variants of concerns of SARS-CoV-2 between the primary doses and booster dose vaccine cohorts of inactivated BBIBP-CorV vaccine. STUDY DESIGN: In this observational study Plaque Reduction Neutralization Test (PRNT) assay was done on pooled serum samples of the recipients of primary two doses of inactivated BBIBP-CorV and on the pooled serum samples of recipients of a booster dose of inactive BBIBP-CorV. The neutralizing antibody titers against the wild (Wuhan) strain and the variants of concern (alpha, beta and delta) were compared. RESULTS: The serum sample pool from the booster cohort had high neutralizing antibody titers against the SARS-CoV-2 variants compared to the pooled serum samples of the recipients of primary two doses of inactivated BBIBP-CorV and the difference was statistically significant. The observed fold reduction in antibody titers from the serum pool of recipients of two doses of BBIBP-CorV vaccine were 3.7-fold, 14.6-fold and 10.4-fold compared to 1.8 -fold, 6.5-fold and 3.8-fold reduction against the alpha, beta and delta lineages respectively in the serum pool of recipient of a booster dose (three doses of BBIBP-CorV). CONCLUSION: Booster doses of inactive BBIBP-CORV offered better protection against the variants of concern of SARS-CoV-2.

COVID-19 Crisis Management: Lessons From the United Arab Emirates Leaders.

This study analyses the UAE leadership's approach in response to the COVID-19 crisis through the Organization for Economic Co-operation and Development's Strategic Crisis Management Framework. This framework analyzes the crisis management in three phases: the preparedness, the response to mitigate damage and the feedback mechanism after the crisis. The analysis showed that the key components of the UAE's crisis management included efficient and able governance, integrated utilization of public-private partnerships and a global workforce of excellence. As a result, the UAE now ranks among the top 10 countries worldwide for its leadership and proactive approach during the COVID-19 pandemic, according to Global Response to Infectious Diseases Index. The SWOT analysis on the response toward COVID-19 crisis management helped in critically analyzing and understanding the UAE's unified and systematic response to the pandemic, which provides developing and developed countries alike a new high standard for leadership and effective public health management.

Serological Assays for Assessing Postvaccination SARS-CoV-2 Antibody Response.

Serological assays for measuring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies have crucial applications in the control and surveillance of the current COVID-19 pandemic. A large number of such assays have been developed and are now commercially available. However, there are limited studies evaluating the performance of these tests. We evaluated the performances of the following six commercially available serological assays for detecting SARS-CoV-2 antibodies: (i) Genscript cPass surrogate virus neutralization test (Genscript cPass), (ii) Diasorin-SARS-CoV-2 S1/S2 IgG detection (Diasorin-S1/S2 IgG), (iii) Alinity SARS-CoV-2 IgG II (Alinity IgG II), (iv) Diasorin-SARS-CoV-2 TrimericS IgG (Diasorin-TrimericS IgG), (v) Roche Elecsys anti-SARS-CoV-2-cobas (Roche Elecsys), and (vi) AESKU enzyme linked immunosorbent assay (AESKULISA). The results of these tests were compared against the gold standard plaque reduction neutralization test (PRNT). Roche Elecsys had the highest sensitivity, and the Genscript cPass had the highest specificity. Diasorin-TrimericS IgG had the best overall performance with the highest agreement with the PRNT results. Parallel testing of Genscript cPass with Diasorin-TrimericS IgG and Diasorin-S1/S2 IgG had the optimum performance. Based on the receiver operating characteristic (ROC) curve, lowering the cutoff from 30% to 20% in the Genscript cPass significantly increased the sensitivity and the overall agreement with the PRNT results. Commercially available serological assays are good alternatives to the standard PRNT. However, further studies on larger sample numbers are required for optimization of the assay cutoff values and for evaluation of cost effectiveness. IMPORTANCE Commercial serological assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are now widely available. This study adds new knowledge regarding the optimization of these assays for evaluating postvaccination antibodies status. It highlights the positive and negative aspects of each assay in terms of sensitivity, specificity, and positive and negative predictive values, compared to the gold standard neutralization test. When using serological assays to assess postvaccine immune status, a balance of all parameters needs to be considered and not simply the high specificity. This balance is particularly relevant in the current situation where countries are aiming to mass vaccinate their populations and bring this pandemic under control. Assays with good sensitivity will have a lower percentage of false negatives and thus provide confidence for vaccination. Understanding the strengths and limitations of commercially available serological assays is important, not only for better application of these tests but also to understand the immune response and the duration of protection postvaccination.

Understanding perception and acceptance of Sinopharm vaccine and vaccination against COVID-19 in the UAE.

BACKGROUND: In the current COVID-19 pandemic, the world has reached an important milestone where vaccinations are discovered and are proven to be effective against SARS-COV-2 infections. Though vaccines against COVID-19 are now available, around the globe there is some hesitancy in getting the vaccine. This hesitancy to get vaccinated against COVID-19 is a complex phenomenon with various factors playing a role. This study aims at understanding the perception and expectations of the people about COVID-19 vaccine and the factors influencing the vaccine acceptance. This information is crucial to challenge vaccine hesitancy and to win the combat against the COVID-19 Pandemic through voluntary vaccine efforts. METHODS: A cross-sectional survey among the residents of the UAE to understand the expectations and perception on vaccination against COVID-19. The survey was conducted online, and the survey design included participant samples to be representative of UAE's demographics. The results of the survey were analysed with various demographical variables of interest. RESULTS: The survey showed that people were more likely to get vaccinated when vaccines are (i) endorsed by trusted government health authorities, (ii) recommended by physicians and family doctors, and (iii) the merits are effectively communicated through government websites and trusted news channels. Availability of vaccines at multiple sites and providing vaccines free of charges are likely to improve the rate of vaccination. The perceptions, expectations and the motivational factors needed for people to get vaccinated differed with age, gender, marital status, income level, and employment status. CONCLUSION: To attain herd immunity against COVID-19, a large proportion of the population needs to be vaccinated and to achieve this the vaccination campaigns should target on specific expectations and motivational factors pertaining to each target group to successfully overcome the challenge of vaccine hesitancy.

Evaluation of six different rapid methods for nucleic acid detection of SARS-COV-2 virus.

In the current coronavirus disease 2019 (COVID-19) pandemic there is a mass screening of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) happening around the world due to the extensive spread of the infections. There is a high demand for rapid diagnostic tests to expedite the identification of cases and to facilitate early isolation and control spread. Hence this study evaluates six different rapid nucleic acid detection assays that are commercially available for SARS-CoV-2 virus detection. Nasopharyngeal samples were collected from 4981 participants and were tested for the SARS-CoV-2 virus by the gold standard real-time reverse-transcription polymerase chain reaction (RT-PCR) method and with one of these six rapid methods of detection. Evaluation of the rapid nucleic acid detection assays was done by comparing the results of these rapid methods with the gold standard RT-qPCR results for SARS-COV-2 detection. AQ-TOP had the highest sensitivity (98%) and a strong kappa value of 0.943 followed by Genechecker and Abbot ID NOW. The POCKIT (ii RT-PCR) assay had the highest test accuracy of 99.29% followed by Genechecker and Cobas Liat. Atila iAMP showed the highest percentage of invalid reports (35.5%) followed by AQ-TOP with 6% and POCKIT with 3.7% of invalid reports. Genechecker system, Abbott ID NOW, and Cobas Liat were found to have the best performance and agreement when compared with the standard RT-PCR for COVID-19 detection. With further research, these rapid tests have the potential to be employed in large-scale screening of COVID-19.

Evaluation of RNA Extraction-Free Method for Detection of SARS-CoV-2 in Salivary Samples for Mass Screening for COVID-19.

In this COVID-19 pandemic, there is a dire need for cost-effective and less time-consuming alternatives for SARS-CoV-2 testing. The RNA extraction-free method for detecting SARS-CoV-2 in saliva is a promising option. This study found that it has high sensitivity (85.34%), specificity (95.04%), and was comparable to the gold standard nasopharyngeal swab (NPS) sample tests. The method showed good agreement between salivary and NPS samples, with a kappa coefficient of 0.797. However, there are variations in the sensitivity and specificity based on the RT-PCR kit used. The Thermo Fisher Applied Biosystems showed high sensitivity, positive predictive value (PPV), and negative predictive value (NPV) but also showed a higher percentage of invalid reports. On the other hand, the BGI kit showed high specificity, better agreement (kappa coefficient) between the results of saliva and NPS samples, and higher correlation between the Ct values of saliva and NPS samples. Thus, the RNA extraction-free method for salivary sample serves as an effective alternative screening method for COVID-19.

Evaluation of pooling of samples for testing SARS-CoV- 2 for mass screening of COVID-19.

BACKGROUND: The current pandemic of the SARS-CoV-2 virus, widely known as COVID-19, has affected millions of people around the world. The World Health Organization (WHO) has recommended vigorous testing to differentiate SARS-CoV-2 from other respiratory infections to aid in guiding appropriate care and management. Situations like this have demanded robust testing strategies and pooled testing of samples for SARS-CoV-2 virus has provided the solution to mass screening of people for COVID-19. A pooled testing strategy can be very effective in testing when resources are limited, yet it comes with its own limitations. These benefits and limitations need critical consideration when it comes to testing highly infectious diseases like COVID-19. METHODS: This study evaluated the pooled testing of nasopharyngeal swabs for SARS-COV-2 by comparing the sensitivity of individual sample testing with 4-and 8-pool sample testing. Median cycle threshold (Ct) values were compared, and the precision of pooled testing was assessed through an inter- and intra-assay of pooled samples. Coefficient of variance was calculated for inter- and intra-assay variability. RESULTS: The sensitivity becomes considerably lower when the samples are pooled. There is a high percentage of false negative reports with larger sample pool size and when the patient viral load is low or weak positive samples. High variability was seen in the intra- and inter-assay, especially among weak positive samples and when more number of samples are pooled together. CONCLUSION: As COVID - 19 infection numbers and need for testing remain high, we must meticulously evaluate the testing strategy for each country depending on its testing capacity, infrastructure, economic strength, and need to determine the optimal balance on the cost-effective strategy of resource saving and risk/ cost of missing positive patients.