Influenza Epidemiology and Vaccine Effectiveness among Patients with Influenza-Like Illness, Viral Watch Sentinel Sites, South Africa, 2005–2009

Introduction: Influenza vaccination for healthcare personnel is not obligatory in Mexico, and compliance relies on promotion and persuasion. The objective of this study was to determine the impact of influenza vaccination compliance on the reduction of influenza and influenza-like illness among healthcare personnel throughout two consecutive influenza seasons. Methodology: A retrospective study comparing cases of influenza and influenza-like illness among vaccinated and unvaccinated healthcare personnel registered in a Mexican 500-bed University Hospital surveillance and immunization registry during seasons 2015-16 and 2016-17. Results: Total influenza immunization compliance was 21.3% and 42.7%, respectively. Reduction of the number of influenza-like illness (58 in 2015-16 and 15 in 2016-17; P = 0.0001) and confirmed influenza cases (28 in 2015-16 and 13 in 2016-17; P = 0.036) was evident. During 2016-17, influenza activity in the community was higher than 2015-16 (4800 and 1338 cases, respectively). Conclusions: Increased influenza vaccination compliance among healthcare personnel was associated with reduction of the overall number of influenza and influenza-like illness cases, even in the setting of high activity of the disease in the community through 2016-17 and reported suboptimal vaccine effectiveness during both seasons.

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Vaccine effectiveness in preventing laboratory-confirmed influenza in Navarre, Spain: 2013/14 mid-season analysis

Eurosurveillance ◽

10.2807/1560-7917.es2014.19.6.20700 ◽

2014 ◽

Vol 19 (6) ◽

Cited By ~ 17

Author(s):

J Castilla ◽

I Martínez-Baz ◽

A Navascués ◽

M Fernandez-Alonso ◽

G Reina ◽

...

Keyword(s):

Primary Healthcare ◽

Influenza A ◽

Vaccine Effectiveness ◽

Preventive Effect ◽

Influenza Like Illness ◽

Trivalent Vaccine

We estimate mid-2013/14 season vaccine effectiveness (VE) of the influenza trivalent vaccine in Navarre, Spain. Influenza-like illness cases attended in hospital (n=431) and primary healthcare (n=344) were included. The overall adjusted VE in preventing laboratory-confirmed influenza was 24% (95% CI: ?14 to 50). The VE was 40% (95% CI: ?12 to 68) against influenza A(H1)pdm09 and 13% (95% CI: ?36 to 45) against influenza A(H3). These results suggest a moderate preventive effect against influenza A(H1)pdm09 and low protection against influenza A(H3).

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SAS: A Platform of Spike Antigenicity for SARS-CoV-2

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.713188 ◽

2021 ◽

Vol 9 ◽

Author(s):

Lu Zhang ◽

Ruifang Cao ◽

Tiantian Mao ◽

Yuan Wang ◽

Daqing Lv ◽

...

Keyword(s):

South Africa ◽

Monoclonal Antibodies ◽

Reference Strain ◽

Experimental Tests ◽

Vaccine Effectiveness ◽

Experimental Results ◽

Spike Protein ◽

Binding Assays ◽

Current Version ◽

Antigenic Sites

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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Effectiveness of influenza vaccine among health care personnel in Thailand, 2018/19 season

European Journal of Public Health ◽

10.1093/eurpub/ckaa165.1096 ◽

2020 ◽

Vol 30 (Supplement_5) ◽

Author(s):

T Eamchotchawalit ◽

P Piyaraj ◽

P Narongdej ◽

S Charoensakulchai ◽

C Chanthowong

Keyword(s):

Health Care ◽

Influenza Vaccine ◽

Influenza Vaccination ◽

Seasonal Influenza ◽

Influenza Season ◽

Influenza Infection ◽

Vaccine Effectiveness ◽

Health Care Personnel ◽

Seasonal Influenza Vaccine ◽

Influenza Like Illness

Abstract Background Influenza vaccination is the most effective way of preventing influenza infections and it is recommended for the entire health care personnel in Thailand. However, the evidence of influenza vaccine effectiveness (VE) among health care personnel is lacking in Thailand. The objective of this study was to estimate influenza vaccine effectiveness (VE) against laboratory confirmed medically attended influenza illness for the 2018/9 season among health care personnel who at risk for influenza infection in Bangkok, the capital of Thailand. Methods Throat swab specimens were collected from patients with influenza-like illness (ILI) presenting to outpatient clinics and tested for influenza virus by RT-PCR, between October 2018 and September 2019. A test-negative case-control design was used to estimate influenza VE against medically-attended laboratory-confirmed influenza in outpatient settings. Cases were influenza-like illness (ILI) patients who tested positive for influenza, and controls were influenza negative patients. Results During the 2018/19 season 373 samples were collected; 57 (15.3%) were positive for influenza, 70.2% A un-subtyped and 29.8% B. Adjusted VE against all influenza viruses for this influenza season was -31.7% (95% confidence interval (CI): -40.2 to 66.4), against influenza A un-subtyped, it was 43.9% (95% CI: -30.6 to 75.9) and against influenza B, it was 52.0% (95% CI: (-73.9 to 86.8). Conclusions The seasonal influenza vaccine was moderately effective against medically attended lab-confirmed influenza infection in health care personnel in Bangkok, Thailand in the 2018-19 influenza season. Key messages The seasonal influenza vaccine was moderately effective against medically attended lab-confirmed influenza infection in health care personnel in Bangkok. Increasing seasonal influenza vaccination among health care personnel in Thailand may decrease medically attended influenza-associated ILI cases in this population.

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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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