Estimating vaccine effectiveness in preventing laboratory-confirmed influenza in outpatient settings in South Africa, 2015

Since the outbreak of SARS-CoV-2, antigenicity concerns continue to linger with emerging mutants. As recent variants have shown decreased reactivity to previously determined monoclonal antibodies (mAbs) or sera, monitoring the antigenicity change of circulating mutants is urgently needed for vaccine effectiveness. Currently, antigenic comparison is mainly carried out by immuno-binding assays. Yet, an online predicting system is highly desirable to complement the targeted experimental tests from the perspective of time and cost. Here, we provided a platform of SAS (Spike protein Antigenicity for SARS-CoV-2), enabling predicting the resistant effect of emerging variants and the dynamic coverage of SARS-CoV-2 antibodies among circulating strains. When being compared to experimental results, SAS prediction obtained the consistency of 100% on 8 mAb-binding tests with detailed epitope covering mutational sites, and 80.3% on 223 anti-serum tests. Moreover, on the latest South Africa escaping strain (B.1.351), SAS predicted a significant resistance to reference strain at multiple mutated epitopes, agreeing well with the vaccine evaluation results. SAS enables auto-updating from GISAID, and the current version collects 867K GISAID strains, 15.4K unique spike (S) variants, and 28 validated and predicted epitope regions that include 339 antigenic sites. Together with the targeted immune-binding experiments, SAS may be helpful to reduce the experimental searching space, indicate the emergence and expansion of antigenic variants, and suggest the dynamic coverage of representative mAbs/vaccines among the latest circulating strains. SAS can be accessed at https://www.biosino.org/sas.

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Influenza vaccine effectiveness by test-negative design – Comparison of inpatient and outpatient settings

Vaccine ◽

10.1016/j.vaccine.2016.02.039 ◽

2016 ◽

Vol 34 (14) ◽

pp. 1672-1679 ◽

Cited By ~ 31

Author(s):

Shuo Feng ◽

Benjamin J. Cowling ◽

Sheena G. Sullivan

Keyword(s):

Influenza Vaccine ◽

Vaccine Effectiveness ◽

Outpatient Settings ◽

Design Comparison

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Vaccine effectiveness against hospital admission in South African health care workers who received a homologous booster of Ad26.COV2 during an Omicron COVID19 wave: Preliminary Results of the Sisonke 2 Study.

10.1101/2021.12.28.21268436 ◽

2021 ◽

Author(s):

Glenda E Gray ◽

Shirley COLLIE ◽

Nigel Garrett ◽

Ameena Goga ◽

Jared Champion ◽

...

Keyword(s):

South Africa ◽

Health Care ◽

Health Care Workers ◽

Booster Dose ◽

Hospital Admissions ◽

Vaccine Effectiveness ◽

Care Organization ◽

African Health ◽

Care Workers ◽

Vaccine Booster

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

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Interim seasonal influenza vaccine effectiveness estimates as proxy for final estimates: Analysis of systematically identified matched pairs of interim/final estimates from test-negative design studies in outpatient settings from 2010/11 to 2018/19

Expert Review of Vaccines ◽

10.1080/14760584.2021.1899821 ◽

2021 ◽

Author(s):

George N. Okoli ◽

Tiba Abdulwahid ◽

Florentin Racovitan ◽

Christiaan H. Righolt ◽

Salaheddin M. Mahmud

Keyword(s):

Influenza Vaccine ◽

Seasonal Influenza ◽

Vaccine Effectiveness ◽

Matched Pairs ◽

Design Studies ◽

Seasonal Influenza Vaccine ◽

Outpatient Settings

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Influenza vaccine effectiveness in preventing laboratory-confirmed influenza in outpatient settings: A test-negative case-control study in Beijing, China, 2016/17 season

Vaccine ◽

10.1016/j.vaccine.2018.07.077 ◽

2018 ◽

Vol 36 (38) ◽

pp. 5774-5780 ◽

Cited By ~ 9

Author(s):

Shuangsheng Wu ◽

Yang Pan ◽

Xinxin Zhang ◽

Li Zhang ◽

Wei Duan ◽

...

Keyword(s):

Influenza Vaccine ◽

Case Control Study ◽

Case Control ◽

Vaccine Effectiveness ◽

Negative Case ◽

Outpatient Settings ◽

Beijing China ◽

Control Study

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Influenza Vaccine Effectiveness in Inpatient and Outpatient Settings in the United States, 2015–2018

Clinical Infectious Diseases ◽

10.1093/cid/ciaa407 ◽

2020 ◽

Author(s):

Mark W Tenforde ◽

Jessie Chung ◽

Emily R Smith ◽

H Keipp Talbot ◽

Christopher H Trabue ◽

...

Keyword(s):

United States ◽

High Risk ◽

Influenza Vaccine ◽

Patient Characteristics ◽

Respiratory Illness ◽

The United States ◽

Vaccine Effectiveness ◽

Influenza Activity ◽

Outpatient Settings ◽

Negative Controls

Abstract Background Demonstration of influenza vaccine effectiveness (VE) against hospitalized illness in addition to milder outpatient illness may strengthen vaccination messaging. Our objective was to compare patient characteristics and VE between United States (US) inpatient and outpatient VE networks. Methods We tested adults with acute respiratory illness (ARI) for influenza within 1 outpatient-based and 1 hospital-based VE network from 2015 through 2018. We compared age, sex, and high-risk conditions. The test-negative design was used to compare vaccination odds in influenza-positive cases vs influenza-negative controls. We estimated VE using logistic regression adjusting for site, age, sex, race/ethnicity, peak influenza activity, time to testing from, season (overall VE), and underlying conditions. VE differences (ΔVE) were assessed with 95% confidence intervals (CIs) determined through bootstrapping with significance defined as excluding the null. Results The networks enrolled 14 573 (4144 influenza-positive) outpatients and 6769 (1452 influenza-positive) inpatients. Inpatients were older (median, 62 years vs 49 years) and had more high-risk conditions (median, 4 vs 1). Overall VE across seasons was 31% (95% CI, 26%–37%) among outpatients and 36% (95% CI, 27%–44%) among inpatients. Strain-specific VE (95% CI) among outpatients vs inpatients was 37% (25%–47%) vs 53% (37%–64%) against H1N1pdm09; 19% (9%–27%) vs 23% (8%–35%) against H3N2; and 46% (38%–53%) vs 46% (31%–58%) against B viruses. ΔVE was not significant for any comparison across all sites. Conclusions Inpatients and outpatients with ARI represent distinct populations. Despite comparatively poor health among inpatients, influenza vaccination was effective in preventing influenza-associated hospitalizations.

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Heterogeneity in influenza seasonality and vaccine effectiveness in Australia, Chile, New Zealand and South Africa: early estimates of the 2019 influenza season

Eurosurveillance ◽

10.2807/1560-7917.es.2019.24.45.1900645 ◽

2019 ◽

Vol 24 (45) ◽

Author(s):

Sheena G Sullivan ◽

Carmen S Arriola ◽

Judy Bocacao ◽

Pamela Burgos ◽

Patricia Bustos ◽

...

Keyword(s):

South Africa ◽

New Zealand ◽

Southern Hemisphere ◽

Northern Hemisphere ◽

Influenza Season ◽

Vaccine Effectiveness ◽

Point Estimates ◽

Influenza Seasonality

We compared 2019 influenza seasonality and vaccine effectiveness (VE) in four southern hemisphere countries: Australia, Chile, New Zealand and South Africa. Influenza seasons differed in timing, duration, intensity and predominant circulating viruses. VE estimates were also heterogeneous, with all-ages point estimates ranging from 7–70% (I2: 33%) for A(H1N1)pdm09, 4–57% (I2: 49%) for A(H3N2) and 29–66% (I2: 0%) for B. Caution should be applied when attempting to use southern hemisphere data to predict the northern hemisphere influenza season.

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Time and Latitude in South Africa

International Astronomical Union Colloquium ◽

10.1017/s0252921100026816 ◽

1972 ◽

Vol 1 ◽

pp. 27-38

Author(s):

J. Hers

Keyword(s):

South Africa ◽

Cape Town ◽

Astronomical Observations ◽

Royal Observatory ◽

The Republic ◽

Astronomical Determination ◽

Limited Accuracy ◽

Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

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