Impact of the Sinopharm’s BBIBP-CorV vaccine in preventing hospital admissions and death in infected vaccinees: Results from a retrospective study in the emirate of Abu Dhabi, United Arab Emirates (UAE)

Efficacy and limitations of SARS-CoV-2 vaccines - A systematic review

The emergence of the SARS-CoV-2 virus worldwide led to the call for the development of effective and safe vaccines to contain the spread and effects of COVID-19. Using information from 40 publications, including clinical trials and observational studies from 2019 to 2024, this review assesses the effectiveness, safety, and limitations of four major vaccines: Sinopharm (BBIBP-CorV), Moderna (mRNA-1273), Pfizer-BioNTech (BNT162b2), and CoronaVac. Pfizer-BioNTech and Moderna's mRNA vaccines proved to be more effective than others; Moderna's vaccines showed an efficacy of 94.1 % against symptomatic infection, while Pfizer-BioNTech's vaccines showed an efficacy of up to 95 %, against severe diseases and hospitalization. These vaccinations, which included protection against Omicron and Delta variants, offered notable protection against serious illness, hospitalization, and mortality. Severe adverse events were rare while most adverse events were mild to moderate, such as headaches, fatigue, and localized reactions. In contrast, inactivated virus vaccines such as Sinopharm and CoronaVac with efficacies ranging from 50 to 79 % against symptomatic infection showed lower levels of effectiveness. In Phase 3 trial, Sinopharm showed 72.8 % efficacy, whereas CoronaVac demonstrated roughly 67 % efficacy in population against hospitalization and severe disease. Booster doses were required for adequate immunological response, especially against novel strains, as these vaccinations proved to be less effective in older populations. They showed considerable safety profiles, with mild side effects, but their low immunogenicity is concerning. This review emphasizes the importance of continuously evaluating vaccines in response to the evolving virus, essential for improving international immunization programs.

Effect of Inactivated Vaccines Against SARS-CoV-2 on Immunogenicity Outcome

OBJECTIVES

The purpose of this study was to measure and examine the levels of IgG, IgM, and Spike antibody induced by inactivated vaccines, including CoronaVac and BBIBP-CorV.

METHODS

Two groups of healthy adults over 18 years old (50 participants per group), who had previously received 1 dose of either BBIBP-CorV or CoronaVac and receiving either a homologous booster of BBIBP-CorV or a heterologous booster of CoronaVac. Serum IgG, IgM, and Spike antibody levels against SARS-COV-2 were measured using magnetic particle chemiluminescence immunoassay and the ELISA method.

RESULTS

The results showed that both spike antibody and IgG/IgM antibodies elicited by a CoronaVac booster following 1 dose of BBIBP-CorV were significantly higher than those elicited by either a homologous BBIBP-CorV booster or a heterologous BBIBP-CorV booster. The Spike antibody against SARS-COV-2 induced by the heterologous CoronaVac booster reached 200.3, which is substantially greater than that induced by the homologous BBIBP-CorV booster (127.5 pg/mL). Conversely, the Spike antibody against SARS-COV-2 induced by the heterologous BBIBP-CorV booster reached 53.93 pg/mL, which is substantially greater than that induced by the homologous CoronaVac booster (9.60 pg/mL).

CONCLUSIONS

In summary, CoronaVac is immunogenic as a booster dose following 1 dose of BBIBP-CorV and is immunogenically superior to both the homologous booster and the heterologous BBIBP-CorV booster.

Vitamin D as an Adjuvant Immune Enhancer to SARS-Cov-2 Vaccine

The SARS-CoV-2 vaccine is an important keystone in fighting against the virus. The vaccination alone could not prevent all SARS-CoV-2 viral infections or even its spread, especially after the emergence of newly mutant strains. The immune response to the SARS-CoV-2 vaccines varies greatly from one person to another. Age, along with adequate micronutrients, especially vitamin D, are major factors influencing immunity. We aimed to analyze SARS-CoV-2 vaccine neutralization potency and the total IgG antibodies along with 25-hydroxy-cholecalciferol concentrations in a cohort of healthy Egyptian vaccinated adults. 196 individuals were included; 145 females and 51 males, with an age range between 22 and 59 years old, from the first time of vaccination and over 16 weeks long. Three blood samples were taken from each individual at three time points; before the 1st dose of vaccination, before the 2nd dose of vaccination, and after 8 weeks of complete vaccination. The samples were analyzed using a chemiluminescent immunoassay to measure vitamin D level and titer of neutralizing and IgG antibodies. A lower level of neutralizing antibodies was detected in deficient and insufficient vitamin D-vaccinated individuals. However, a sufficient titer was detected in individuals with normal vitamin D. Vitamin D deficiency is associated with a suppressed immune response against SARS-CoV-2 despite vaccination. Thus, we made inquiries about using vitamin D as an adjuvant to SARS-CoV-2 vaccination, and its relation with the production of anti-SARS-CoV-2 antibodies.

Effectiveness of vaccination (Sinopharm) among Covid-19 positive patients in a tertiary care hospital

The SARS-CoV-2, has caused a pandemic of acute respiratory disease, 'coronavirus disease 2019' (Covid-19), posed a major threat to health and the international economy during past few years. It is believed that vaccine can stop the rapid spread of the disease. The aim of this study was to evaluate the effect of the Sinopharm vaccine in terms of mortality and severity of the disease among Covid-19 positive patients. This observational cross-sectional study was done at the Department of Medicine and Department of Pathology Shaikh Khalifa Bin Zayed Al-Nahyan/CMH Teaching Hospital (Poonch Medical College), Rawalakot AJK Pakistan from July 2021 to September 2021. Total 350 individuals with greater than or equal to 18 years of age, who were tested positive for Covid-19, were included. Patients who had received two doses of the vaccine at least 28 days apart were considered as vaccinated. The Sinopharm vaccination status was checked among patients. The severity of Covid-19 was categorized as mild, moderate and severe. A log rank regression test was applied to determine significant difference in disease severity and survival rate. The patients age range was 25-60 years (the patients mean age was 55 years). The majority of participants, 69.1% (n=242), were vaccinated by Sinopharm, and 30.9% (n=108) were non-vaccinated. Most patients had mild disease 80% (n=280) followed by moderate disease 9.7% (n=34), and severe disease 6.6% (n=23), and stratification analysis had significant (p ≤ 0.05) association between vaccinated individuals and disease severity. The overall mortality rate was 3.7%. The mortality rate was 8% (n=9) in none vaccinated individuals, whereas 1.65% (n=4) in vaccinated individuals. The Sinopharm vaccine after both doses was found effective in reducing mortality and disease severity by 98.3% and 94.4%. The study concluded that Sinopharm vaccine after two doses at least 28 days apart given to patients, after two weeks of vaccination is highly effective in reducing the mortality, disease severity and hospital admission in Covid-19 positive patients.

A real-world study of BBIBP-CorV vaccine effectiveness in a Sri Lanka rural province

Objective

Real-world studies assessing the effectiveness of the BBIBP-CorV vaccine in low and middle-income countries are limited. We evaluated the BBIBP-CorV vaccine's effectiveness in reducing COVID-19 symptomatic disease, hospitalisation, severe disease, and mortality during the third wave of the pandemic in Sri Lanka.

Methods

We conducted a test-negative case-control study in North Central Province from May 2021 to February 2022. Evidence of vaccination was obtained from the national registry. The PCR-positive patients were cases, while negative individuals were controls. Adjusted vaccine effectiveness (aVE) was computed for fully, partially, and non-vaccinated groups in reducing symptomatic disease, hospitalisation, severe disease, and mortality.

Results

Our study involved 3305 cases and 3418 controls. The overall aVE for preventing PCR-positive infection in fully vaccinated was 30·8 % (95 % CI:17·9-41·6). In fully vaccinated over 60 years, the overall aVE was 72·3 % (95 % CI: 49·7-84·8). Full vaccination with BBIBP-CorV is effective in reducing hospitalisation, severe COVID-19 disease, and death, with aVE rates of 70·3 % (95 % CI: 57·9-79·0), 88·9 % (95 % CI: 81·8-93·2), and 92·3 % (95 % CI: 84·8-96·1) respectively.

Conclusion

Individuals who have received two doses of the BBIBP-CorV vaccine are protected against hospitalisation, severe COVID-19 disease, and death. Duration of protection against hospitalisation, severe COVID-19, and fatal COVID-19 sustained at least 121 days, with no sign of waning during that time.

COVID-19 in the Arab countries: Three-year study

Background

Twenty-two Arab countries share a common language, history, and culture. Nevertheless, governmental policies, healthcare systems, and resources differ from one Arab country to another. We have been following Coronavirus (COVID-19) from the beginning in each Arab country. In the present study, we aimed to assess the prevalence of COVID-19 in the Arab world and to compare these findings with other significantly affected countries.

Methods

Websites of the World Health Organization, World COVID-vaccinations tracker, Worldometer, and Ministries of Health were used to extract COVID-19 data in all Arab countries between the period January 2020 to December 2022.

Results

All Arab countries had 14,218,042 total confirmed COVID-19 cases, 13,384,924 total recovered cases and 173,544 total related deaths. The trend demonstrated that the third quarter of 2021 recorded the highest death toll and the first quarter of 2022 recorded the highest number of confirmed and recovered cases. Compared to the top 15 affected countries, the Arab world ranked last as it had the lowest overall incidence per million population (PMP) of 31,609. The data on total deaths PMP showed that India had the lowest number of deaths with only 377 cases followed by the Arab world with 386 cases.

Conclusions

Although the number of confirmed, death, and recovered cases of COVID-19 have greatly reduced in the last quarter of 2022 in most Arab countries, many Arab countries still need to re-campaign about COVID-19 vaccines and raise awareness programs about boosters. COVID-19 has had a relatively smaller impact on Arab countries than on other countries that have been significantly affected.

Effectiveness of ChAdOx1 nCoV-19 and BBIBP-CorV vaccines against COVID-19-associated hospitalisation and death in the Seychelles infected adult population

BACKGROUND

The Seychelles COVID-19 vaccination campaign was initiated using two different vaccines during the first wave of the pandemic in 2021. This observational study estimated vaccine effectiveness against severe outcomes (hospitalisation and/or death) from individuals infected with COVID-19 in the Seychelles adult population during Beta and Delta variant transmission.

METHODS

This nationwide retrospective cohort study included all Seychellois residents aged ≥ 18 years who tested positive by RT-PCR or rapid antigen test for COVID-19 between January 25, 2021, and June 30, 2021. We measured the relative risk (RR) of laboratory-confirmed SARS-CoV-2 hospitalisation and/or death among individuals partially or fully vaccinated with ChAdOx1 nCoV-19 (SII Covishield) or BBIBP-CorV (Sinopharm) vaccines compared to unvaccinated individuals using modified Poisson regression. Controlling for age, gender and calendar month, vaccine effectiveness was estimated as 1-RR ≥14 days after the first dose and ≥7 days after the second dose for each available vaccine versus an unvaccinated control group.

RESULTS

A total of 12,326 COVID-19 infections were reported in adult Seychellois residents between January 25, 2021, and June 30, 2021. Of these, 1,287 individuals received one dose of either BBIBP-CorV (Sinopharm) or ChAdOx1-nCoV-19 (SII Covishield) vaccine, and 5,225 individuals received two doses. Estimated adjusted effectiveness of two doses of either Sinopharm or SII Covishield was high, at 70% (95% CI 58%-78%) and 71% (95% CI 62%-78%) respectively. Sinopharm maintained high levels of protection against severe outcomes in partially vaccinated individuals at 61% (95% CI 36%-76%), while the effectiveness of one dose of SII Covishield was low at 29% (95% CI 1%-49%).

CONCLUSIONS

This observational study demonstrated high levels of protection of two doses of two vaccine types against severe outcomes of COVID-19 during the first wave of the pandemic driven by Beta (B.1.351) and Delta (B.1.617.2) variant predominance. One dose of ChAdOx1-nCoV-19 (Covishield SII) was found to be inadequate in protecting the general adult population against hospitalisation and/or death from COVID-19.

Immunogenicity and efficacy of VLA2001 vaccine against SARS-CoV-2 infection in male cynomolgus macaques

BACKGROUND

The fight against COVID-19 requires mass vaccination strategies, and vaccines inducing durable cross-protective responses are still needed. Inactivated vaccines have proven lasting efficacy against many pathogens and good safety records. They contain multiple protein antigens that may improve response breadth and can be easily adapted every year to maintain preparedness for future seasonally emerging variants.

METHODS

The vaccine dose was determined using ELISA and pseudoviral particle-based neutralization assay in the mice. The immunogenicity was assessed in the non-human primates with multiplex ELISA, neutralization assays, ELISpot and intracellular staining. The efficacy was demonstrated by viral quantification in fluids using RT-qPCR and respiratory tissue lesions evaluation.

RESULTS

Here we report the immunogenicity and efficacy of VLA2001 in animal models. VLA2001 formulated with alum and the TLR9 agonist CpG 1018™ adjuvant generate a Th1-biased immune response and serum neutralizing antibodies in female BALB/c mice. In male cynomolgus macaques, two injections of VLA2001 are sufficient to induce specific and polyfunctional CD4+ T cell responses, predominantly Th1-biased, and high levels of antibodies neutralizing SARS-CoV-2 infection in cell culture. These antibodies also inhibit the binding of the Spike protein to human ACE2 receptor of several variants of concern most resistant to neutralization. After exposure to a high dose of homologous SARS-CoV-2, vaccinated groups exhibit significant levels of protection from viral replication in the upper and lower respiratory tracts and from lung tissue inflammation.

CONCLUSIONS

We demonstrate that the VLA2001 adjuvanted vaccine is immunogenic both in mouse and NHP models and prevent cynomolgus macaques from the viruses responsible of COVID-19.

Safety and immunogenicity of the NVX-CoV2373 vaccine as a booster in adults previously vaccinated with the BBIBP-CorV vaccine

This phase 3 observer-blind, randomized, controlled study was conducted in adults ≥18 years of age to assess the safety and immunogenicity of NVX-CoV2373 as a heterologous booster compared to BBIBP-CorV when utilized as a homologous booster. Approximately 1000 participants were randomly assigned in a 1:1 ratio to receive a single dose of NVX-CoV2373 or BBIBP-CorV after prior vaccination with 2 or 3 doses of BBIBP-CorV. Solicited adverse events (AEs) were collected for 7 days after vaccination. Unsolicited AEs were collected for 28 days following the booster dose and serious adverse and adverse events of special interest (AESI) were collected throughout the study. Anti-spike IgG and neutralizing antibodies against SARS-CoV-2 were measured at baseline, day 14, day 28, and day 180. The study achieved its primary non-inferiority endpoint and also demonstrated statistically higher neutralization responses when NVX-CoV2373 was utilized as a heterologous booster compared with BBIBP-CorV as a homologous booster. Both vaccines had an acceptably low reactogenicity profile, and no new safety concerns were found. Heterologous boosting with NVX-CoV2373 was a highly immunogenic and safe vaccine regimen in those previously vaccinated with BBIBP-CorV.

Real-world effectiveness of the inactivated COVID-19 vaccines against variant of concerns: meta-analysis

BACKGROUND

COVID-19 has killed over 6 million people worldwide, making it the worst global health disaster since the 1918 influenza pandemic. Experts have worked to establish the source, track and analyse the disease, and produce treatment and preventative guidelines. Inactivated vaccines have little evidence of efficacy compared to mRNA and adenoviral vector vaccines; however, three doses of both mRNA and inactivated vaccines appear to provide significant and lasting protection against severe disease and mortality. This study examines inactivated vaccine effectiveness data by disease status, age, gender, primary immunisation, booster doses, and SARS-CoV2 virus types.

METHODS

We conducted a quantitative epidemiological meta-analysis study to assess the vaccine effectiveness of inactivated COVID-19 vaccines. Data extraction was performed on the selected studies, and data analysis was conducted using a random-effects model to determine consolidated assessments of vaccine effectiveness. Subgroup analyses were conducted for gender, age, disease level, and vaccine status, and sensitivity analyses were conducted to assess the robustness of the results.

RESULTS

The overall effect size of inactivated COVID-19 vaccinations was statistically significant (p-value<0.05), suggesting that complete vaccination should be the primary method of vaccination. Partial vaccination was associated with lower levels of vaccine effectiveness (70.18 95% CI 57.33-83.02) than complete vaccination (79.52 95% CI 67.88-91.71)) and booster vaccination (84.22 95% CI 74.34-94.10), suggesting that it is essential to finish the recommended vaccine series and receive booster doses. Fig.-3: Partially vaccinated individuals showed a vaccine effect size of 70.18 (95% CI 57.33-83.02), indicating that the vaccine was moderately effective in preventing COVID-19 among this group. Fully vaccinated individuals showed a vaccine effect size of 79.52 (95% CI 67.88-91.71), indicating a higher level of vaccine effectiveness. Finally, booster-vaccinated individuals showed a vaccine effect size of 84.22 (95% CI 74.34-94.10), indicating the highest level of vaccine effectiveness.

CONCLUSION

Inactivated COVID-19 vaccines are highly effective in preventing COVID-19, and complete vaccination and booster vaccination are associated with higher levels of vaccine effectiveness compared to partial vaccination. These findings highlight the importance of completing the recommended vaccine series and receiving booster doses to provide greater protection against COVID-19.

SARS-CoV-2 vaccines in China could reduce COVID-19-related respiratory syndromes and deaths: A retrospective cohort study

Background

Information is limited regarding the effectiveness of the inactivated vaccine for COVID-19 approved in China in preventing infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) when administered in real-world conditions.

Methods

We retrospectively surveyed 1352 patients with a positive SARS-CoV-2 nucleic acid test treated at a major tertiary medical center in Foshan city (Guangdong, China) between November 2022 and February 2023. The exposure group was patients who had previously received the COVID-19 vaccine, which included patients who had received different doses of the vaccine and different vaccine types. The primary outcome of this study was the effectiveness of the vaccine in preventing severe disease and death among SARS-CoV-2-infected patients.

Results

We found a mortality rate of 12.1 % associated with COVID-19. The results showed that an increase in the number of vaccine doses was associated with a reduction in in-hospital mortality. When compared to unvaccinated patients, vaccinated patients had an 8.5 % lower mortality rate. There was also a statistically significant reduction in the risk of death among vaccinated patients compared to unvaccinated patients (OR = 0.521 [95 % CI, 0.366 to 0.741]). Patients who had received the vaccine had a 22.8 % reduction in the risk of severe disease. In addition, the use of antiviral drugs decreased progressively with increasing vaccine doses (P < 0.05). Of these, anticoagulation, Paxlovid, and mechanical ventilation were used least frequently in the one-dose group.

Conclusions

The vaccines approved in China mitigated the incidence of severe COVID-19 and reduced mortality. These findings suggest that COVID-19 vaccination can help to control the pandemic.

Effectiveness of homologous or heterologous immunization regimens against SARS-CoV-2 after two doses of inactivated COVID-19 vaccine: A systematic review and meta-analysis

We aimed to evaluate the effectiveness or efficacy of heterologous or homologous COVID-19 vaccine regimens against COVID-19-related outcomes after primary immunization with two doses of CoronaVac or Sinopharm COVID-19 vaccines. PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched up to 31 October 2022. The primary measure was vaccine effectiveness against COVID-19 infection with homologous or heterologous booster. The results showed heterologous and homologous booster significantly improved effectiveness against COVID-19 infection compared to primary immunization. The effectiveness against COVID-19 infection was 89.19% (95%CI 78.49, 99.89) for heterologous mRNA vaccine booster, 87.00% (95%CI 82.14, 91.85) for non-replicating vector vaccine booster, 69.99% (95%CI 52.16, 87.82) for homologous booster, and 51.48% (95%CI 41.75, 61.21) for two doses of inactivated vaccine. Homologous and heterologous regimens were also effective against SARS-CoV-2 variants, and more evidence is still needed to confirm our findings.

Upper extremity deep vein thrombosis following BBIBP-CorV COVID-19 vaccine (Sinopharm vaccine): A case report

Key Clinical Message

In patients with acute symptoms such as pain, swelling, and erythema of the upper extremities shortly after receiving COVID-19 vaccines, even inactivated virus vaccines, these symptoms may indicate thrombosis, which may be due to the vaccination.

Abstract

BBIBP-CorV COVID-19 vaccine (Sinopharm vaccine) is an inactivated whole virus vaccine to control the COVID-19 pandemic. Studies concluded that inactivated COVID-19 vaccines do not increase the risk of thrombosis. This report presents a 23-year-old man with the chief complaint of severe pain, swelling, and erythema of the right upper extremity following his second dose of the Sinopharm vaccine. Duplex ultrasound of the right upper extremity revealed upper extremity deep vein thrombosis, and treatment started with oral anticoagulation. It is probably the first upper extremity deep vein thrombosis case following inactivated COVID-19 vaccines.

Efficacy and effectiveness of inactivated vaccines against symptomatic COVID-19, severe COVID-19, and COVID-19 clinical outcomes in the general population: a systematic review and meta-analysis

Background

Inactivated, whole-virion vaccines have been used extensively in the SARS-CoV-2 pandemic. Its efficacy and effectiveness across regions have not been systematically evaluated. Efficacy refers to how well a vaccine performs in a controlled environment. Effectiveness refers to how well it performs in real world settings.

Methods

This systematic review and meta-analysis reviewed published, peer-reviewed evidence on all WHO-approved inactivated vaccines and evaluated their efficacy and effectiveness against SARS-CoV-2 infection, symptomatic infection, severe clinical outcomes, and severe COVID-19. We searched Pubmed (including MEDLINE), EMBASE (via OVID), Web of Science Core Collection, Web of Science Chinese Science Citation Database, and Clinicaltrials.gov.

Findings

The final pool included 28 studies representing over 32 million individuals reporting efficacy or effectiveness estimates of complete vaccination using any approved inactivated vaccine between January 1, 2019 and June 27, 2022. Evidence was found for efficacy and effectiveness against symptomatic infection (OR 0.21, 95% CI 0.16-0.27, I2 = 28% and OR 0.32, 95% CI 0.16-0.64, I2 = 98%, respectively) and infection (OR 0.53, 95% CI 0.49-0.57, I2 = 90% and OR 0.31, 95% CI 0.24-0.41, I2 = 0%, respectively) for early SARS-CoV-2 variants of concern (VoCs) (Alpha, Delta), and for waning of vaccine effectiveness with more recent VoCs (Gamma, Omicron). Effectiveness remained robust against COVID-related ICU admission (OR 0.21, 95% CI 0.04-1.08, I2 = 99%) and death (OR 0.08, 95% CI 0.00-2.02, I2 = 96%), although effectiveness estimates against hospitalization (OR 0.44, 95% CI 0.37-0.53, I2 = 0%) were inconsistent.

Interpretation

This study showed evidence of efficacy and effectiveness of inactivated vaccines for all outcomes, although inconsistent reporting of key study parameters, high heterogeneity of observational studies, and the small number of studies of particular designs for most outcomes undermined the reliability of the findings. Findings highlight the need for additional research to address these limitations so that more definitive conclusions can be drawn to inform SARS-CoV-2 vaccine development and vaccination policies.

Funding

Health and Medical Research Fund on COVID-19, Health Bureau of the Government of the Hong Kong SAR.

Real-World Effectiveness of Four Types of COVID-19 Vaccines

BACKGROUND

There is a scarcity of evidence regarding the real-world effectiveness of coronavirus disease 2019 (COVID-19) vaccines. This was the first study to evaluate the effectiveness of four types of vaccines against asymptomatic and symptomatic infection, and COVID-19 outcomes among the general population.

METHODS

This was a matched comparison group quasi-experimental study conducted in Jordan between 1 January and 29 August 2021. In the first part of the study, 1200 fully vaccinated individuals were matched with 1200 unvaccinated control participants. In order to measure vaccine effectiveness, the infection rates of both vaccinated and unvaccinated groups were calculated. The second part of the study included measuring specific anti-SARS CoV-2 immune cells and antibodies.

RESULTS

BNT162b2 (Pfizer, New York, NY, USA) showed a significantly higher effectiveness against asymptomatic COVID-19 infection (91.7%) and hospitalization (99.5%) than BBIBP-CorV (Sinopharm, Beijing, China) (88.4% and 98.7%, respectively) and ChAdOx1 nCoV-19 (AstraZeneca, Cambridge, UK) (84.3%, and 98.9%, respectively). The effectiveness rates of the Sputnik V (Gamaleya Research Institute, Moscow, Russia) vaccine against asymptomatic, symptomatic, and hospitalization were 100%, 100%, and 66.7%, respectively. The highest median anti-spike (S) IgG values were seen in individuals who received BNT162b2 (2.9 AU/mL) and ChAdOx1 nCoV-19 (2.8 AU/mL) vaccines. The levels of anti-S IgG were significantly decreased after 7 months of vaccination with BNT162b2 and BBIBP-CorV. There were significant decreases in the median number of neutralizing antibodies one month and seven months after receiving BNT162b2 (from 88.5 to 75.2 4 Bioequivalent Allergen Unit per milliliter/mL), BBIBP-CorV (from 69.5 to 51.5 BAU/mL), and ChAdOx1 nCoV-19 (from 69.2 to 58.BAU/mL) vaccines. The highest percentage of T cells specific to COVID-19 vaccine was found in individuals who received BNT162b2 (88.5%).

CONCLUSION

All four vaccines evaluated in this study showed effectiveness against asymptomatic COVID-19 infection, symptomatic infection, hospitalization, and death. Furthermore, BNT162b2, BBIBP-CorV, and ChAdOx1 nCoV-19 induced high levels of immunology markers within one month of vaccination.

Effectiveness and Safety of Inactivated SARS-CoV-2 Vaccine (BBIBP-CorV) among Healthcare Workers: A Seven-Month Follow-Up Study at Fifteen Central Hospitals

BACKGROUND

During a pandemic, healthcare workers are at high risk of contracting COVID-19. To protect these important individuals, it is highly recommended that they receive the COVID-19 vaccine. Our study focused on evaluating the safety and efficacy of Egypt's first approved vaccine, the Sinopharm vaccine (BBIBP-CorV), and comparing these findings with other vaccines.

METHODS

An observational study was conducted in fifteen triage and isolation hospitals, from the 1st of March until the end of September 2021. The study included fully vaccinated and unvaccinated participants, and we measured vaccine effectiveness (using 1-aHR), the incidence rate of severely to critically ill hospitalized cases, COVID-19-related work absenteeism, and the safety of the vaccine as outcomes.

RESULTS

Of the 1364 healthcare workers who were interviewed, 1228 agreed to participate. After taking the hazard ratio into account, the vaccine effectiveness was found to be 67% (95% CI, 80-43%) for symptomatic PCR-confirmed cases. The incidence rate ratio for hospitalization was 0.45 (95% CI, 0.15-1.31) in the vaccinated group compared to the unvaccinated group, and there was a significant reduction in absenteeism among the vaccinated group (p < 0.007). Most adverse events were mild and well tolerated. Vaccinated pregnant and lactating mothers did not experience any sentinel adverse events.

CONCLUSION

Our study found that the BBIBP-CorV vaccine was effective in protecting healthcare workers from COVID-19.

Comparison of Biological, Pharmacological Characteristics, Indications, Contraindications, Efficacy, and Adverse Effects of Inactivated Whole-Virus COVID-19 Vaccines Sinopharm, CoronaVac, and Covaxin: An Observational Study

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging viral zoonotic illness that has developed a distinctive and threatening situation globally. Worldwide, many vaccines were introduced to fight against the COVID-19 pandemic. The present study aims to compare the bio-pharmacological characteristics, indications, contraindications, efficacy, and adverse effects of inactivated whole-virus COVID-19 vaccines, Sinopharm, CoronaVac, and Covaxin. Initially, 262 documents and 6 international organizations were selected. Finally, 41 articles, fact sheets, and international organizations were included. The data were recorded from the World Health Organization (WHO), Food and Drug Administration (FDA) USA, Web of Science, PubMed, EMBASE, and Scopus. The results demonstrated that these three inactivated whole-virus COVID-19 vaccines, Sinopharm, CoronaVac, and Covaxin, received emergency approval from the FDA/WHO, and all three of these vaccines are beneficial for the prevention of the COVID-19 pandemic. The Sinopharm vaccine has been recommended during pregnancy and for people of all age groups, and the CoronaVac and Covaxin vaccines are recommended for people over 18 years of age and older. These three vaccines have recommended intramuscular doses of 0.5 mL each, with a 3-4 week interval. These three vaccines can be stored in a refrigerator at +2 to +8 °C. The common adverse effects of these vaccines are pain at the injection site, redness, fatigue, headache, myalgias, general lethargy, body ache, arthralgia, nausea, chills, fever, and dizziness. The overall mean efficiency for the prevention of the COVID-19 disease is 73.78% for Sinopharm, 70.96% for CoronaVac, and 61.80% for Covaxin. In conclusion, all three inactivated whole-virus COVID-19 vaccines, Sinopharm, CoronaVac, and Covaxin, are beneficial for the prevention of the COVID-19 pandemic. However, evidence suggests that the overall impact of Sinopharm is slightly better than that of CoronaVac and Covaxin.

The Prevalence of Side Effects of Sinopharm COVID-19 Vaccine: An Experience From Pakistan

Introduction Vaccination for coronavirus disease 2019 (COVID-19) helps develop protective immunity against COVID-19 without experiencing potentially severe illness. Many vaccines are used worldwide, but there is little data on the efficacy and side effects of the Sinopharm vaccine. Therefore, this study aimed to investigate the reported adverse effects of the Sinopharm vaccine among participants. Methods This prospective cross-sectional study was conducted in multiple hospitals in Karachi, Pakistan. The study was eight months, from April 1, 2022, to November 30, 2022. A total of 600 participants who gave informed consent and had received their first and second doses of the Sinopharm vaccine were included in the study. As hypertension and diabetes mellitus (DM) are common prevalent conditions in our population, the duration of DM and hypertension were documented as means and standard deviations apart from age, height, and weight. Side effects of the Sinopharm vaccine were reported as frequencies and percentages. Results The study findings showed that out of 600 participants, 376 (62.7%) were males and 224 (37.3%) were females; their mean age was 42.79±14.44 years. Among them, 130 (21.7%) had hypertension, and 138 (23.0%) had DM. All participants received the Sinopharm vaccine. Fever was the most frequently reported adverse effect following the first dose of the Sinopharm vaccine in 308 (51.3% of participants), followed by burning at the injection site in 244 (40.7% of participants) and pain at the injection site in 228 (38.0% of participants). Following the second dose of the Sinopharm vaccine, fever was the most frequently reported side effect in 254 (42.3%) participants, followed by pain at the injection site in 236 (39.5%) participants and burning at the site of injection in 210 (35.0%) participants. Moreover, joint pain in 194 (32.3%), shortness of breath in 170 (28.3%), swelling of glands in 168 (28.0%), chest pain in 164 (27.3%), and muscle pain were reported by 140 (23.3%) participants. The level of satisfaction showed that the majority of the participants, 334 (55.7%), were satisfied, 132 (22.0%) were very satisfied with their vaccination, and only 12 (2.0%) were dissatisfied. Conclusion This study concluded that fever was the most frequent side effect after both doses of the Sinopharm vaccine. Pain and burning at the injection site and joint pain were among the other common side effects reported by most participants. The Sinopharm COVID-19 vaccine had mild, predictable, and non-life-threatening side effects after the first and second doses.

Studying the effects of booster shots and antibody responses to the SARS-CoV-2 vaccination over time in health personnel

Background

With the emergence of mutant versions that lead to continual spreading and recurrent infections of SARS-CoV-2, the COVID-19 vaccines can assist protection for high risk groups, particularly health workers. Even while booster shots have been widely used, longitude studies on immune responses in healthy subjects are uncommon.

Methods

Eighty-five healthcare workers who received the BBIBP-CorV vaccine were prospectively enrolled and monitored for up to ten months. Automated Pylon immunoassays were used to quantify total anti-SARS-CoV2 antibody levels (TAb), surrogate neutralization antibody levels (NAb), and antibody avidities over the course of the follow-up. Additionally, hematology analyses were performed.

Results

Pylon antibody testing revealed that every participant tested negative at the beginning, and 88.2% of them tested positive about 14 days after receiving their second dosage. The TAb levels and NAb levels peaked in 76.5% and 88.2% of the subjects, respectively, at the same time. Age was connected with the peak antibody levels, but not with gender, BMI, or baseline hematological factors. The positive rates and the antibody levels had already started to decline three months following the second injection. The antibody levels and avidities quickly increased following the booster doses to levels that were considerably greater than the peak antibody responses before to the booster shots. Hematology testing revealed no safety concerns with immunizations.

Conclusion

In healthy workers, the two doses of BBIBP-CorV were able to induce humoral immunity; however, 3 months following vaccination, the antibody levels started to decline. The BBIBP-CorV booster injections increase both the quantity and quality of antibodies, which gave support for utilizing booster doses to prolong the duration of the vaccine’s protective effects.

Characterisation of the Antibody Response in Sinopharm (BBIBP-CorV) Recipients and COVID-19 Convalescent Sera from the Republic of Moldova

The early availability of effective vaccines against SARS-CoV-2, the aetiologic cause of COVID-19, has been at the cornerstone of the global recovery from the pandemic. This study aimed to assess the antispike RBD IgG antibody titres and neutralisation potential of COVID-19 convalescent plasma and the sera of Moldovan adults vaccinated with the Sinopharm BBIBP-CorV vaccine. An IgG ELISA with recombinant SARS-CoV-2 spike RBD and two pseudovirus-based neutralisation assays have been developed to evaluate neutralising antibodies against SARS-CoV-2 in biosafety level 2 containment facilities. A significant moderate correlation was observed between IgG titres and the overall neutralising levels for each neutralisation assay (ρ = 0.64, p < 0.001; ρ = 0.52, p < 0.001). A separate analysis of convalescent and vaccinated individuals showed a higher correlation of neutralising and IgG titres in convalescent individuals (ρ = 0.68, p < 0.001, ρ = 0.45, p < 0.001) compared with vaccinated individuals (ρ = 0.58, p < 0.001; ρ = 0.53, p < 0.001). It can be concluded that individuals who recovered from infection developed higher levels of antispike RBD IgG antibodies. In comparison, the Sinopharm-vaccinated individuals produced higher levels of neutralising antibodies than convalescent plasma.

Effectiveness of BBIBP-CorV vaccine in preventing SARS-CoV2 infection and severe outcomes in people living with multiple sclerosis: A population-based study

BACKGROUND

The objective of the present study was to estimate the effectiveness of the BBIBP-CorV vaccine (VE) in preventing SARS-CoV-2 infection, related hospitalization, and death among people living with multiple sclerosis (PLWMS).

METHODS

In this population-based retrospective observational study, data on all PLWMS, vaccination, SARS-CoV-2 tests, hospitalization, and deaths were collected in Isfahan, Iran between February 9, 2021, and November 4, 2021. We estimated the hazard ratio between vaccinated (partially and fully) and unvaccinated groups using the Andersen-Gill extension of the Cox proportional hazards model. We also performed Cox proportional hazards analysis to identify risk factors for breakthrough infection and COVID-19-related hospitalization in fully-immunized group.

RESULTS

Of the 9869 PLWMS, 1368 were in partially-vaccinated group, 4107 were in the fully-vaccinated group, and 3794 were in the unvaccinated group. In the partially-vaccinated group, the estimated VE against COVID-19 infection was 39.3% (16%, 56.1%), hospitalization was 64.9% (1.3%, 87.5%), and mortality was 92.7% (88.8%, 100%). The respective results for the fully-vaccinated group were 63.9% (56%, 70.3%), 75.7% (57.5%, 86.1%), and 100%. Progressive MS was independently associated with a greater risk of breakthrough infection (HR=1.952, 95%CI: 1.174-3.246, p = 0.010). Older adults (≥50 years vs. 18-49 years, HR=3.115, 95%CI: 1.145-8.470, p = 0.026) and those on rituximab (HR=7.584; 95% CI: 1.864-30.854; p = 0.005) were at an increased risk of COVID-19-related hospitalization.

CONCLUSION

This study showed that two doses of the BBIBP-CorV vaccine can effectively prevent COVID-19 infection and hospitalization among PLWMS. Old PLWMS and those who treating with rituximab are at increased risk of hospitalization after receiving two doses of the vaccine.

Incidence of SARS-CoV-2 infection in hospital workers before and after vaccination programme in East Java, Indonesia-A retrospective cohort study

Background

The incidence of the Coronavirus Disease 2019 (COVID-19) among healthcare workers (HCWs) is widespread. It is important to understand COVID-19 characteristics among HCWs before and after vaccination. We evaluated the incidence of COVID-19 among HCWs in East Java, Indonesia comparing the characteristics of the disease between the pre- vs post-vaccination periods.

Methods

A retrospective observational study was conducted among HCWs in two major hospitals in East Java, Indonesia, between April 01, 2020, and Oct 31, 2021. All HCWs were offered vaccination with inactivated viral vaccine (CoronaVac) from Jan 15, 2021. Therefore, we divided the time of the study into the pre-vaccination period (between April 01, 2020, and Jan 14, 2021) and post-vaccination period (between Jan 15 and Oct 31, 2021). We then compared the pattern of COVID-19 infections, and hospitalisations between these periods.

Findings

A total of 434 (15.1%) and 649 (22.6%) SARS-CoV-2 infections were reported among study participants (n = 2878) during the pre-vaccination and post-vaccination periods, respectively. The vaccine effectiveness was 73.3% during the first 3-4 months after vaccination but this decreased to 17.6% at 6-7 months after vaccination, which coincided with the emergence of the delta variant. The overall hospitalisation rate was reduced from 23.5% in the pre-vaccination period to 14.3% in the post-vaccination period. Hypertension appeared to be the strongest risk factor affecting hospitalisation in the pre-vaccination period. However, the risk due to hypertension was reduced in the post-vaccination period.

Interpretation

The risk to contract COVID-19 remains high among HCWs in East Java, Indonesia. Vaccination is important to reduce infection and hospitalisation. It is essentially important to evaluate the characteristics of COVID-19 infection, hospitalisation, the impact of co-morbidities and vaccine effectiveness in order to improve the measures applied in protecting HCWs during the pandemic.

Funding

Mandate Research Grant No:1043/UN3.15/PT/2021, Universitas Airlangga, Indonesia.

Effectiveness of COVID-19 vaccines on hospitalization and death in Guilan, Iran: a test-negative case-control study

OBJECTIVES

The present study was conducted to estimate the effectiveness of (BBIBP)-CorV (Sinopharm), ChAdOx1-S/nCoV-19 (AZD1222, Oxford-AstraZeneca), rAd26-rAd5 (Gam-COVID-Vac, Sputnik V), and BIV1-CovIran (COVIran Barekat) and BBV152 COVAXIN (Bharat Biotech) vaccines against hospitalization and death of COVID-19 in Guilan Province of Iran from May 22 to December 21, 2021.

METHODS

This test-negative case-control study was conducted on the population aged 5 years and above by extracting information from local databases (The Medical Care Monitoring Center and The Integrated Health System). A logistic regression analysis was performed to estimate the effectiveness of the vaccines against COVID-19 hospitalization and death.

RESULTS

The total study population was 42,084, including 19,500 cases (with a positive Reverse Transcriptase-Polymerase Chain Reaction test admitted to hospitals in Guilan Province) and 22,586 controls (with a negative Reverse Transcriptase-Polymerase Chain Reaction test). Among the admitted patients, 1887 deaths occurred. The maximum effectiveness of BBIBP-CorV (Sinopharm) in preventing temporary hospitalization and regular hospitalization was observed 151 days after receiving the second dose, 95% (95% CI: 67-99.4%) and 85% (95% CI: 77-91%) respectively. The maximum effectiveness of the BBIBP-CorV (Sinopharm) vaccine 91-120 days after receiving the second dose against death was showed 56% (95% CI: 33-71%). The maximum effectiveness of ChAdOx1-S/nCoV-19 (AZD1222, Oxford-AstraZeneca) and BIV1-CovIran (COVIran Barekat) in preventing regular hospitalization and death was observed 121-150 and 61-90 days (respectively) after receiving the second dose, reaching 98% (95% CI: 94-99%) and 92% (95% CI: 48-99%), respectively for ChAdOx1-S/nCoV-19 and 95% (95% CI: 91-97%) and 89% (95% CI: 55-98%) respectively, for BIV1-CovIran.

CONCLUSION

For almost all vaccines, the study observed an increase in effectiveness against hospitalization and death over time.

Neutralizing Antibodies as Predictors of Vaccine Breakthrough Infection in Healthcare Workers Vaccinated with or without a Heterologous Booster Dose: A Cohort Study during the Third COVID-19 Wave in Peru

We evaluated neutralizing antibody (NAbs) levels as a protective factor against vaccine breakthrough infection (VBI) in healthcare workers (HCWs) during the third COVID-19 wave in Peru. This retrospective cohort study employed the information from a private laboratory in Lima (Peru) of HCW who received only two BBIBP-CorV vaccines or (additionally) a heterologous booster with BNT162b2. We evaluated the association between the VBI and the levels of NAbs at 21, 90, 180, and 210 days after the BBIBP-CorV second dose. NAbs were calculated with the cPass™ SARS-CoV-2 Neutralization Antibody Detection kit (surrogate virus neutralization test (sVNT)) and the Elecsys^® anti-SARS-CoV-2 S Test. Of the 435 HCW evaluated, 31.72% had an infection previous to vaccination, 68.28% received a booster dose, and 23.21% had a VBI during the third wave. The variables associated with a lower risk of VBI were male sex (aRR: 0.43) and those who had (180 days after BBIBP-CorV inoculation) NAbs levels ≥ 60% (aRR: 0.58) and ≥90% (aRR: 0.59) on cPass™, and ≥500 with Elecsys^® (aRR: 0.58). HCW whose NAbs persisted at higher levels six months after the BBIBP-CorV showed a lower risk of suffering from a VBI during the third COVID-19 wave.

Risk of hospitalization and vaccine effectiveness among COVID-19 patients in the UAE during the Delta and Omicron outbreaks

Introduction

A rapid increase in COVID-19 cases due to the spread of the Delta and Omicron variants in vaccinated populations has raised concerns about the hospitalization risk associated with, and the effectiveness of, COVID-19 vaccines.

Method

This case-control study aims to determine the hospitalization risk associated with the inactivated BBIBP-CorV (Sinopharm) and mRNA BNT162b2 (Pfizer-BionTech) vaccines, and their effectiveness reducing the rate of hospital admission between 28 May 2021 and 13 January 2022, during the Delta and Omicron outbreaks. The estimation of vaccine effectiveness of 4,618 samples was based on the number of patients hospitalized at different vaccination statuses, adjusted for confounding variables.

Results

Hospitalization risk increases in patients affected with the Omicron variant if patients are aged ≤ 18 years (OR 6.41, 95% CI 2.90 to 14.17; p < 0.001), and in patients affected with the Delta variant if they are aged > 45 years (OR 3.41, 95% CI 2.21 to 5.50; p < 0.001). Vaccine effectiveness reducing the rate of hospital admission for fully vaccinated participants infected with the Delta and Omicron variants was similar for both the BBIBP-CorV (94%, 95% CI 90% to 97%; 90%, 95% CI 74% to 96%) and BNT162b2 vaccines (95%, 95% CI 61% to 99.3%; 94%, 95% CI 53% to 99%), respectively.

Discussion

The BBIBP-CorV and BNT162b2 vaccines utilized in the UAE vaccination program were highly effective in reducing the rate of COVID-19-related hospitalization during the Delta and Omicron outbreaks, and further effort must be taken to achieve high vaccine coverage rates in children and adolescents in the global context to reduce the hospitalization risk associated with COVID-19 on an international scale.

Effectiveness of Inactivated COVID-19 Vaccines against Delta-Variant COVID-19: Evidence from an Outbreak in Inner Mongolia Autonomous Region, China

Phase 3 clinical trials and real-world effectiveness studies showed that China's two main inactivated COVID-19 vaccines are very effective against serious illness. In November 2021, an outbreak occurred in the Inner Mongolia Autonomous Region that provided an opportunity to assess the vaccine effectiveness (VE) of these inactivated vaccines against COVID-19 caused by the delta variant. We evaluated VE with a retrospective cohort study of close contacts of infected individuals, using a generalized linear model with binomial distribution and log-link function to estimate risk ratios (RR) and VE. A total of 8842 close contacts were studied. Compared with no vaccination and adjusted for age, presence of comorbidity, and time since last vaccination, full vaccination reduced symptomatic infection by 62%, pneumonia by 64% and severe COVID-19 by 90%; reductions associated with homologous booster doses were 83% for symptomatic infection, 92% for pneumonia and 100% for severe COVID-19. There was no significant decline in two-dose VE for any outcome for up to 325 days following the last dose. There were no differences by vaccine brand. Inactivated vaccines were effective against delta-variant illness, and were highly effective against pneumonia and severe COVID-19; VE was increased by booster doses.

Adverse Effects of Sinopharm COVID-19 Vaccine among Vaccinated Medical Students and Health Care Workers

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease caused a highly problematic situation worldwide. Various vaccines were launched to combat the COVID-19 pandemic. This study aims to investigate the adverse effects of first and second doses of the Sinopharm vaccine among vaccinated medical and dental students and healthcare workers. A well-established questionnaire was distributed online, and 414 medical and dental students and healthcare workers (HCW) comprising 355 females (85.7%) and 59 males (14.3%) participated; all were vaccinated with two doses of Sinopharm. The most common side effect was pain at the injection site after dose one in 253 respondents (61.3%) and after dose two in 161 respondents (38.9%). Other symptoms included general lethargy in 168 (40.6%), myalgia/body pain in 99 (23.9%), low-grade fever in 93 (22.4%), and headache in 87 (21%) respondents. Common side effects reported after the second dose of the vaccine following pain at the injection site included general lethargy in 21.3% (88), headache in 10.4% (43), myalgia/body pain in 9.9% (41), and low-grade fever in 6.1% (25) of the respondents. In conclusion, common adverse effects of the Sinopharm vaccine were pain at the injection site, general lethargy, myalgia, body pain, low-grade fever, and headache. These adverse effects were mild in intensity for both doses but slightly more frequent and severe for the first dose than the second dose.

Anti-SARS-Cov-2 S-RBD IgG Formed after BNT162b2 Vaccination Can Bind C1q and Activate Complement

Background

The ability of vaccine-induced antibodies to bind C1q could affect pathogen neutralization. In this study, we investigated C1q binding and subsequent complement activation by anti-spike (S) protein receptor-binding domain (RBD) specific antibodies produced following vaccination with either the mRNA vaccine BNT162b2 or the inactivated vaccine BBIBP-CorV.

Methods

Serum samples were collected in the period of July 2021-March 2022. Participants' demographic data, type of vaccine, date of vaccination, as well as adverse effects of the vaccine were recorded. The serum samples were incubated with S protein RBD-coated plates. Levels of human IgG, IgA, IgM, C1q, and mannose-binding lectin (MBL) that were bound to the plate, as well as formed C3d, and C5b-9 were compared between different groups of participants.

Results

A total of 151 samples were collected from vaccinated (n = 116) and nonvaccinated (n = 35) participants. Participants who received either one or two doses of BNT162b2 formed higher levels of anti-RBD IgG and IgA than participants who received BBIBP-CorV. The anti-RBD IgG formed following either vaccine bound C1q, but significantly more C1q binding was observed in participants who received BNT162b2. Subsequently, C5b-9 formation was significantly higher in participants who received BNT162b2, while no significant difference in C5b-9 formation was found between the nonvaccinated and BBIBP-CorV groups. The formation of C5b-9 was strongly correlated to C1q binding and not to MBL binding, additionally, the ratio of formed C5b-9/bound C1q was significantly higher in the BNT162b2 group.

Conclusion

Anti-RBD IgG formed following vaccination can bind C1q with subsequent complement activation, and the degree of terminal complement pathway activation differed between vaccines, which could play a role in the protection offered by COVID-19 vaccines. Further investigation into the correlation between vaccine protection and vaccine-induced antibodies' ability to activate complement is required.

Long term effectiveness of inactivated vaccine BBIBP-CorV (Vero Cells) against COVID-19 associated severe and critical hospitalization in Morocco

BACKGROUND

We provide national estimates of the real-world Vaccine effectiveness (VE) based on nationally available surveillance data. The study aimed to estimate the effectiveness of the inactivated Covid-19 vaccine BBIBP-CorV (Vero Cells) Sinopharm vaccine currently deployed in Morocco against SARS- CoV-2 severe disease/ hospitalization" within 9 months after vaccination.

METHODS

We conducted a test-negative, case-control study among a population aged 18 years or older who were tested by rt-PCR for SARS-CoV-2 infection from February to October 2021 in Morocco. From the national laboratory COVID-19 database; we identified cases who were rt-PCR positive amongst severe and critical COVID-19 cases and controls who had a negative rt-PCR test for SARS-CoV-2. From the national vaccination register (NVR); individuals vaccinated with COVID-19 Vaccine (Vero Cell) and those unvaccinated were identified and included in the study. The linkage between databases was conducted for the study of Vaccination status based on the timing of the vaccine receipt relative to the SARS-CoV-2 rt-PCR test date. For each person, who tested positive for SARS-CoV-2, we identified a propensity score-matched control participant who was tested negative. We estimated vaccine effectiveness against SARS- CoV-2 severe disease/ hospitalization using conditional logistic regression.

RESULTS

Among 12884 persons who tested positive and 12885 propensity score-matched control participants, the median age was 62 years, 47.2% of whom were female. As a function of time after vaccination of second dose vaccination, vaccine effectiveness during the first month was 88% (95% CI, 84-91), 87% (95% CI: 83-90) during the second and third month, 75% (95% CI: 67-80) during the fourth month, 61% (95% CI: 54-67) during the fifth month, and 64% (95% CI: 59-69) beyond the sixth month. VE remained high and stable during the first three months in the two-age subgroup. In the fourth month, the VE in the older population aged 60 years and above (64%) was reduced by 20 points compared to VE in the younger population (84%).

CONCLUSION

A Sinopharm vaccine is highly protective against serious SARS-CoV-2 infection under real-world conditions. Protection remained high and stable during the first three months following the second dose and decreases slightly beyond the fourth month especially beyond 60 years.

Immunoassay and mass cytometry revealed immunological profiles induced by inactivated BBIBP COVID-19 vaccine

With the global prevalence of COVID-19 and the constant emergence of viral variants, boosters for COVID-19 vaccines to enhance antibody titers in human bodies will become an inevitable trend. However, there is a lack of data on antibody levels and the protective effects of booster injections. This study monitored and analyzed the antibody potency and the antibody responses induced by the booster injection in the subjects who received three vaccine doses. The study was conducted in a multicenter collaboration and recruited 360 healthy adults aged 20-74. Participants received the first, second, and booster doses of inactivated Sinopharm/BBIBP COVID-19 vaccine at 0, 1, and 7 months. Vaccine-induced virus-specific antibody levels (SARS-COV-2-IgA/IgM/IgG) were monitored at multiple time points, surrogate virus neutralization test (sVNT), and the spatial distribution and proportion of immune cells and markers were analyzed using the CyTOF method before vaccination and a month after the second dose. The titers of SARS-CoV-2-IgA/IgM/IgG and neutralizing antibodies increased to a high level in the first month after receiving the second dose of vaccine and declined slowly after that. The antibody levels of SARS-CoV-2-IgG and sVNT were significantly increased at 0.5 months after the induction of the booster (p < 0.05). Despite a downward trend, the antibody levels were still high in the following 6 months. The B cell concentration (in humoral sample) a month after the second injection was significantly reduced compared to that before the vaccine injection (p < 0.05). The proportion of the C01 cell cluster was significantly decreased compared with that before vaccine injection (p < 0.05). Individual cell surface markers showed distinctions in spatial distribution but were not significantly different. This study has shown that serum antibody titer levels will decrease with time by monitoring and analyzing the antibody efficacy and the antibody reaction caused by the booster injection of healthy people who received the whole vaccination (completed three injections). Still, the significant peak of the antibody titer levels after booster highlights the recall immune response. It can maintain a high concentration of antibody levels for a long time, which signifies that the protection ability has been enhanced following the injection of booster immunization. Additionally, CyTOF data shows the active production of antibodies and the change in the immunity environment.

Real-world study of the effectiveness of BBIBP-CorV (Sinopharm) COVID-19 vaccine in the Kingdom of Morocco

Background

The Kingdom of Morocco approved BBIBP-CorV (Sinopharm) COVID-19 vaccine for emergency use on 22 January 2021 in a two-dose, three-to-four-week interval schedule. We conducted a retrospective cohort study to determine real-world BBIBP-CorV vaccine effectiveness (VE) against serious or critical hospitalization of individuals RT-PCR-positive for SARS-CoV-2 during the first five months of BBIBP-CorV use in Morocco.

Methods

The study was conducted among adults 18–99 years old who were tested by RT-PCR for SARS-CoV-2 infection between 1 February and 30 June 2021. RT-PCR results were individually linked with outcomes from the COVID-19 severe or critical hospitalization dataset and with vaccination histories from the national vaccination registration system. Individuals with partial vaccination (< 2 weeks after dose two) or in receipt of any other COVID-19 vaccine were excluded. Unadjusted and adjusted VE estimates against hospitalization for serious or critical illness were made by comparing two-dose vaccinated and unvaccinated individuals in logistic regression models, calculated as (1-odds ratio) * 100%.

Results

There were 348,190 individuals able to be matched across the three databases. Among these, 140,892 were fully vaccinated, 206,149 were unvaccinated, and 1,149 received homologous BBIBP-CorV booster doses. Unadjusted, full-series, unboosted BBIBP-CorV VE against hospitalization for serious or critical illness was 90.2% (95%CI: 87.8—92.0%). Full-series, unboosted VE, adjusted for age, sex, and calendar day of RT-PCR test, was 88.5% (95%CI: 85.8—90.7%). Calendar day- and sex-adjusted VE was 96.4% (95%CI: 94.6—97.6%) for individuals < 60 years, and was 53.3% (95%CI: 39.6—63.9%) for individuals 60 years and older. There were no serious or critical illnesses among BBIBP-CorV-boosted individuals.

Conclusions

Effectiveness of Sinopharm’s BBIBP-CorV was consistent with phase III clinical trial results. Two doses of BBIBP-CorV was highly protective against COVID-19-associated serious or critical hospitalization in working-age adults under real-world conditions and moderately effective in older adults. Booster dose vaccination was associated with complete protection, regardless of age, although only a small proportion of subjects received booster doses.

Effectiveness and Cost-Effectiveness of Inactivated Vaccine to Address COVID-19 Pandemic in China: Evidence From Randomized Control Trials and Real-World Studies

Objective

This study aimed to determine the efficacy, effectiveness, and cost-effectiveness of inactivated COVID-19 vaccines (CoronaVac and BBIBP-CorV) in China using existing international clinical trials and real-world evidence.

Methods

Through a search of PubMed, Embase, Web of Science, and CNKI, studies investigating the effectiveness of inactivated COVID-19 vaccines were identified, and a meta-analysis was undertaken to synthesize the vaccine efficacy and effectiveness data. Moreover, a decision-analytic model was developed to estimate the cost-effectiveness of inactivated vaccines for combating the COVID-19 pandemic in the Chinese context from a societal perspective. Results of the meta-analysis, along with cost data from official websites and works of literature were used to populate the model. Sensitivity analysis was performed to test the robustness of the model results.

Results

A total of 24 studies were included in the meta-analysis. In comparison to no immunization, the effectiveness of inactivated vaccine against COVID-19 infection, hospitalization, ICU admission and death were 65.18% (95% CI 62.62, 67.75), 79.10% (95% CI 71.69, 86.51), 90.46% (95% CI 89.42, 91.50), and 86.69% (95% CI 85.68, 87.70); and the efficacy against COVID-19 infection and hospitalization were 70.56% (95% CI 57.87, 83.24) and 100% (95% CI 61.72, 100). Inactivated vaccine vaccination prevented more infections, hospitalizations, ICU admissions, and deaths with lower total costs, thus was cost-saving from a societal perspective in China. Base-case analysis results were robust in the one-way sensitivity analysis, and the percentage of ICU admission or death and direct medical cost ranked the top influential factors in our models. In the probabilistic sensitivity analysis, vaccination had a 100% probability of being cost-effective.

Conclusion

Inactivated vaccine is effective in preventing COVID-19 infection, hospitalization, ICU admission and avoiding COVID-19 related death, and COVID-19 vaccination program is cost-saving from societal perspective in China.

Immunogenicity Following Two Doses of the BBIBP-CorV Vaccine and a Third Booster Dose with a Viral Vector and mRNA COVID-19 Vaccines against Delta and Omicron Variants in Prime Immunized Adults with Two Doses of the BBIBP-CorV Vaccine

Coronavirus disease 2019 (COVID-19) booster vaccination is being comprehensively evaluated globally due to waning immunity and the emergence of new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. Therefore, this study aimed to evaluate antibody responses in individuals vaccinated with two doses of the BBIBP-CorV vaccine and to explore the boosting effect of the different vaccine platforms in BBIBP-CorV-primed healthy adults, including a viral vector vaccine (AZD122) and mRNA vaccines (BNT162b2 and mRNA-1273). The results showed that in the BBIBP-CorV prime group, the total receptor-binding domain (RBD) immunoglobulin (Ig) and anti-RBD IgG levels waned significantly at three months after receiving the second dose. However, after the booster, RBD-specific binding antibody levels increased. Neutralizing antibody measured by a surrogate neutralization test showed inhibition over 90% against the SARS-CoV-2 delta variant but less than 70% against the omicron variant after the third dose on day 28. All booster vaccines could induce the total IFN-ɣ T-cell response. The reactogenicity was acceptable and well-tolerated without serious adverse events. This study supports the administration of the third dose with either a viral vector or mRNA vaccine for BBIBP-CorV-primed individuals to stimulate antibody and T-cell responses.

Vaccination with the Inactivated Vaccine (Sinopharm BBIBP-CorV) Ensures Protection against SARS-CoV-2 Related Disease

Vaccination against coronavirus disease 2019 (COVID-19) has become an important public health solution. Developing a safe and effective vaccine against COVID-19 is a viable long-term solution to control the pandemic. As one of the two inactivated severe acute respiratory syndrome virus 2 (SARS-CoV-2) vaccines developed in China that entered the WHO emergency use list, Sinopharm BBIBP-CorV, an aluminum-hydroxide-adjuvanted, inactivated whole-virus vaccine, has been widely distributed, with more than 400 million doses administered in more than 40 countries. The evidence of the safety, efficacy, and effectiveness of BBIBP-CorV is gathered and reviewed. We further comment on one of the latest papers that disclosed the effectiveness results between BBIBP-CorV, rAd26-rAd5, and ChAdOx1.

Safety and Immunogenicity of the BBIBP-CorV Vaccine in Adolescents Aged 12 to 17 Years in the Thai Population: An Immunobridging Study

Adolescents can develop a severe form of Coronavirus disease 2019 (COVID-19), especially with underlying comorbidities. No study has examined the efficacy or effectiveness of inactivated COVID-19 vaccines in adolescents. This single-center, prospective cohort study was performed to evaluate the safety and effectiveness of an inactivated COVID-19 vaccine in adolescents using the immunobridging approach at Chulabhorn Hospital. The key eligibility criterion was a healthy clinical condition or stable pre-existing comorbidity. The anti-receptor-binding domain (anti-RBD) antibody concentration at 4 weeks after dose 2 of the vaccine was compared between participants aged 12 to 17 years and those aged 18 to 30 years. Safety profiles included adverse events within 7 days after each dose of the vaccine and any adverse events through 1 month after dose 2 of the vaccine. In the adolescent and adult cohorts, the geometric mean concentration of anti-RBD antibody was 102.9 binding antibody unit (BAU)/mL (95% CI, 91.0−116.4) and 36.9 BAU/mL (95% CI, 30.9−44.0), respectively. The geometric mean ratio of the adolescent cohort was 2.79 (95% CI, 2.25−3.46, p < 0.0001) compared with the adult cohort, meeting the non-inferiority criterion. The reactogenicity was slightly lower in the adolescent than in the adult cohort. No serious adverse events occurred. The inactivated COVID-19 vaccine appears safe and effective in adolescents.

Characteristics of the Third COVID-19 Pandemic Wave with Special Focus on Socioeconomic Inequalities in Morbidity, Mortality and the Uptake of COVID-19 Vaccination in Hungary

Governments are increasingly looking to vaccination to provide a path out of the COVID-19 pandemic. Hungary offers an example to investigate whether social inequalities compromise what a successful vaccine program can achieve. COVID-19 morbidity, mortality, and vaccination coverage were characterized by calculation of indirectly standardized ratios in the Hungarian population during the third pandemic wave at the level of municipalities, classified into deprivation quintiles. Then, their association with socioeconomic deprivation was assessed using ecological regression. Compared to the national average, people living in the most deprived municipalities had a 15-24% lower relative incidence of confirmed COVID-19 cases, but a 17-37% higher relative mortality and a 38% lower vaccination coverage. At an ecological level, COVID-19 mortality showed a strong positive association with deprivation and an inverse association with vaccination coverage (RRVaccination = 0.86 (0.75-0.98)), but the latter became non-significant after adjustment for deprivation (RRVaccination = 0.95 (0.84-1.09), RRDeprivation = 1.10 (1.07-1.14)). Even what is widely viewed as one of the more successful vaccine roll outs was unable to close the gap in COVID-19 mortality during the third pandemic wave in Hungary. This is likely to be due to the challenges of reaching those living in the most deprived municipalities who experienced the highest mortality rates during the third wave.