scholarly journals The Delta Variant Had Negligible Impact on COVID-19 Vaccine Effectiveness in the USA

Author(s):  
Ben Blaiszik ◽  
Carlo Graziani ◽  
James L. Olds ◽  
Ian Foster

The SARS-CoV-2 Delta variant (B.1.617.2) was initially identified in India in December 2020. Due to its high transmissibility, its prevalence in the U.S.A. grew from a near-zero baseline in early May 2021 to nearly 100% by late August 2021, according to CDC tracking. We accessed openly available data sources from the public health authorities of seven U.S. states, five U.S. counties, and the District of Columbia on RT-PCR COVID-19 tests split by the COVID-19 vaccination status of individuals tested during this period. Together, these time series enable estimation and tracking of COVID-19 vaccine effectiveness (VE∗) (against RT-PCR diagnosed infection) concurrently with the growth of Delta variant prevalence in those locations. Our analyses reveal that in each locality the VE∗ for the combined set of all three US vaccines remained relatively stable and quite well-performing, despite the dramatic concurrent rise of Delta variant prevalence. We conclude that the Delta variant does not significantly evade vaccine-induced immunity. The variations in our measured VE∗ appear to be driven by demographic factors affecting the composition of the vaccinated cohorts, particularly as pertains to age distribution. We report that the measured VE∗, aggregated across the collected sites, began at a value of about 0.9 in mid-May, declined to about 0.76 by mid-July, and recovered to about 0.9 by mid-September.SummaryWe estimated local COVID-19 vaccine effectiveness using RT-PCR COVID-19 test data broken out by vaccination status from select localities in the U.S.A. between 15 May and 15 September 2021 while the SARS-CoV-2 Delta variant (B.1.617.2) was ascending from essentially zero prevalence to total dominance of the genome, and showed that the rise of the Delta variant had negligible effect on vaccine effectiveness.

2021 ◽  
Vol 26 (28) ◽  
Author(s):  
Samuel Alizon ◽  
Stéphanie Haim-Boukobza ◽  
Vincent Foulongne ◽  
Laura Verdurme ◽  
Sabine Trombert-Paolantoni ◽  
...  

We analysed 9,030 variant-specific RT-PCR tests performed on SARS-CoV-2-positive samples collected in France between 31 May and 21 June 2021. This analysis revealed rapid growth of the Delta variant in three of the 13 metropolitan French regions and estimated a +79% (95% confidence interval: 52–110%) transmission advantage compared with the Alpha variant. The next weeks will prove decisive and the magnitude of the estimated transmission advantages of the Delta variant could represent a major challenge for public health authorities.


2019 ◽  
Author(s):  
Cecilia Wolff ◽  
Heidi Lange ◽  
Siri Feruglio ◽  
Line Vold ◽  
Emily MacDonald

Abstract Background In Norway, Legionnaires’ disease is reportable upon clinical suspicion to public health authorities and mandatorily notifiable through the Norwegian surveillance system for communicable diseases (MSIS) for both clinicians and laboratories. In the summer of 2017, several European countries reported high notification rates for Legionnaires’ disease, which was not observed in Norway. We evaluated MSIS to assess if it meets its objectives of detecting cases and trends in incidence of Legionnaires’ disease.Methods We retrieved MSIS data from 2008 to 2017 and calculated timeliness as days from sampling to notification, and internal completeness for key variables as the proportion of observations with a value. Where possible, we assessed internal validity on the presence of a plausible value. To estimate external completeness and validity we linked MSIS with hospital reimbursement claims in the Norwegian Patient Registry. To assess acceptability and representativeness, we surveyed doctors in 39 hospitals on their units’ diagnostic and notification procedures, and their use of MSIS.Results There were 438 notified cases. Internal completeness and internal validity were high for key variables (≥95%). The median delay from sampling to notification was 4 days. There were 73 patients in MSIS only, 70 in the Norwegian Patient Registry only, and 351 in both registers. The external completeness of MSIS was 83% (95% CI 80-86%). For external validity, the positive predictive value of MSIS was 83% (95% CI 79-86%). Forty-seven respondents from 28 hospitals described testing procedures. These were inconsistent: 29 (62%) reported no systematic application of criteria for requesting legionella testing. Eighteen (38%) reported testing all patients with suspected pneumonia and a travel history. Thirty-one (66%) found the notification criteria clear.Conclusions Our results suggest that the surveillance in MSIS can detect incidence changes for Legionnaires’ disease over time, by place and person, but likely does not detect every case diagnosed in Norway. We recommend wider investigation of diagnostic procedures in order to improve representativeness and awareness of MSIS notification criteria among clinicians in order to improve acceptability of the surveillance. We also recommend a more comprehensive assessment of whether patients only registered in the Norwegian Patient Registry were true Legionnaires’ disease cases.


Author(s):  
Linda Mueller ◽  
Valentin Scherz ◽  
Gilbert Greub ◽  
Katia Jaton ◽  
Onya Opota

Since the beginning of the COVID-19 pandemic, important health and regulatory decisions relied on the SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) results. Our diagnostic laboratory faced a rapid increase in the number of SARS-CoV-2 RT-PCR, with up to 1,007 tests per day. To maintain a rapid turnaround time to support patient management and public health authorities' decisions, we moved from a case-by-case validation of RT-PCR to an automated validation and immediate transmission of the results to clinicians. To maintain high quality and to track possible aberrant results, we developed a quality-monitoring tool based on a homemade algorithm coded in R. We present the results of this quality-monitoring tool applied to 35,137 RT-PCR results corresponding to 30,198 patients. Patients tested several times led to 4,939 pairwise comparisons; 88% concordant and 12% discrepant. Among the 573 discrepancies, 428 were automatically solved by the algorithm. The most likely explanation for these 573 discrepancies was related for 44.9% of the situations to "Clinical evolution", 27.9% to "Preanalytical" problems, and 25.3% to "Stochastic". Finally, 11 discrepant results could not be explained, including 8 received from external partners for which clinical data were not available. The implemented quality-monitoring strategy allowed to: i) assist the investigation of discrepant results ii) focus the attention of medical microbiologists onto results requiring a specific expertise and iii) maintain an acceptable TAT. This work highlighted the high RT-PCR consistency for the detection of SARS-CoV-2 and the importance of automated processes to handle a huge number of samples while preserving quality.


2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S68-S68
Author(s):  
Jessie Chung ◽  
Brendan Flannery ◽  
Rodolfo Begue ◽  
Herve Caspard ◽  
Laurie Demarcus ◽  
...  

Abstract Background Quadrivalent live attenuated influenza vaccine (LAIV4) was not recommended for use in the United States for the 2016–2017 and 2017–2018 influenza seasons based on US observational studies of vaccine effectiveness (VE) from 2013–2014 to 2015–2016. We pooled individual patient data on children aged 2–17 years enrolled in 5 US studies during these 3 influenza seasons to further investigate VE by vaccine type. Methods Analyses included 17,173 children enrolled in the US Department of Defense Global Laboratory-based Influenza Surveillance Program, US Influenza Vaccine Effectiveness Network, Influenza Incidence Surveillance Project, Influenza Clinical Investigation for Children, and a Louisiana State University study. Participants’ specimens were tested for influenza by reverse transcription-polymerase chain reaction (RT-PCR), culture, or a combination of rapid antigen testing and RT-PCR. VE was calculated by comparing odds of vaccination with either inactivated influenza vaccine (IIV) or LAIV4 among influenza-positive cases to test-negative controls and calculated as 100 × (1 − odds ratio) in logistic regression models with age, calendar time, influenza season, and study site (random effect). Patients were stratified by prior season vaccination status in a subanalysis. Results Overall, 38% of patients (N = 6,558) were vaccinated in the current season, of whom 30% (N = 1,979) received LAIV4. Pooled VE of IIV against any influenza virus was 51% (95% CI: 47, 54) versus 26% (95% CI: 15, 36) for LAIV4. Point estimates for pooled VE against any influenza by age group ranged from 45% to 58% for IIV and 19% to 34% for LAIV4 during the 3 seasons (Figures 1 and 2). Pooled VE against influenza A(H1N1)pdm09 was 67% (95% CI: 62, 72) for IIV versus 20% (95% CI: −6, 39) for LAIV4. Pooled VE against influenza A(H3N2) was 29% (95% CI: 14, 42) for IIV versus 7% (95% CI: −11, 23) for LAIV4, and VE against influenza B was 52% (95% CI: 42, 60) for IIV and 66% (95% CI: 47, 77) for LAIV4. VE against influenza A(H1N1)pdm09 was lower for LAIV4 versus IIV across all strata of prior season vaccination (Figure 3). Conclusion Consistent with individual studies, our pooled analyses found that LAIV4 effectiveness was reduced for all age groups against influenza A(H1N1)pdm09 compared with IIV. This result did not vary based on prior vaccination status. Disclosures H. Caspard, AstraZeneca: Employee, Salary.


2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S25-S25
Author(s):  
Joseph Lewnard ◽  
Yonatan H Grad

Abstract Background Following decades of declining mumps incidence amid widespread vaccination, the US has experienced a resurgence in mumps cases since 2006 driven largely by outbreaks on college campuses. The occurrence of cases among previously-vaccinated individuals and in communities with high vaccine coverage has prompted concerns about performance of the live attenuated mumps vaccine (Jeryl Lynn strain) currently included in the measles-mumps-rubella (MMR) series. It is unclear whether the resurgence is due to antigenic changes in circulating mumps virus, which would warrant consideration of a new vaccine, or to waning vaccine-derived protection, necessitating additional booster doses. Methods We pooled data from studies of vaccine effectiveness to test for waning of protection. We used mathematical models to measure changes in population immunity since mumps vaccine introduction and to assess whether recent mumps transmission dynamics are consistent with hypotheses of waning immunity or vaccine escape. Results We estimate that vaccine-derived protection persists, on average, 29 (95% CI: 17–54) years after receipt of the last dose (Fig. 1). This waning accounts for 66.4% of unexplained variation in estimates of mumps vaccine effectiveness across published studies. Changes in age-specific susceptibility due to vaccine waning and declining transmission track with the current resurgence in cases among young adults in the USA, and explain outbreaks reported among vaccinated adolescents during the late 1980s (Fig. 2). In contrast, vaccine escape would not be expected to result in cases following the observed age distribution (Fig. 3). Routine adult booster vaccination is needed to sustain mumps elimination. Conclusion The resurgence of mumps in the USA since 2006 is attributable to waning of vaccine-derived immunity, suggesting the need for booster doses in adulthood. Trials are needed to assess clinical protection afforded by booster doses in individuals with a history of MMR vaccination. Disclosures J. Lewnard, Pfier: Grant Investigator, Research grant


2021 ◽  
Author(s):  
Sonia Jangra ◽  
Chengjin Ye ◽  
Raveen Rathnasinghe ◽  
Daniel Stadlbauer ◽  
Florian Krammer ◽  
...  

AbstractOne year in the coronavirus disease 2019 (COVID-19) pandemic, the first vaccines are being rolled out under emergency use authorizations. It is of great concern that newly emerging variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can escape antibody-mediated protection induced by previous infection or vaccination through mutations in the spike protein. The glutamate (E) to Lysine (K) substitution at position 484 (E484K) in the receptor binding domain (RBD) of the spike protein is present in the rapidly spreading variants of concern belonging to the B.1.351 and P.1 lineages. We performed in vitro microneutralization assays with both the USA-WA1/2020 virus and a recombinant (r)SARS-CoV-2 virus that is identical to USA-WA1/2020 except for the E484K mutation introduced in the spike RBD. We selected 34 sera from study participants based on their SARS-CoV-2 spike ELISA antibody titer (negative [N=4] versus weak [N=8], moderate [N=11] or strong positive [N=11]). In addition, we included sera from five individuals who received two doses of the Pfizer SARS-CoV-2 vaccine BNT162b2. Serum neutralization efficiency was lower against the E484K rSARS-CoV-2 (vaccination samples: 3.4 fold; convalescent low IgG: 2.4 fold, moderate IgG: 4.2 fold and high IgG: 2.6 fold) compared to USA-WA1/2020. For some of the convalescent donor sera with low or moderate IgG against the SARS-CoV-2 spike, the drop in neutralization efficiency resulted in neutralization ID50 values similar to negative control samples, with low or even absence of neutralization of the E484K rSARS-CoV-2. However, human sera with high neutralization titers against the USA-WA1/2020 strain were still able to neutralize the E484K rSARS-CoV-2. Therefore, it is important to aim for the highest titers possible induced by vaccination to enhance protection against newly emerging SARS-CoV-2 variants. Two vaccine doses may be needed for induction of high antibody titers against SARS-CoV-2. Postponing the second vaccination is suggested by some public health authorities in order to provide more individuals with a primer vaccination. Our data suggests that this may leave vaccinees less protected against newly emerging variants.


2021 ◽  
Vol 3 (4) ◽  
pp. p1
Author(s):  
Dr. Simran Kahai ◽  
Dr. Gayle Herrington ◽  
Domenico Folino

While efforts to vaccinate the general public have been trending in a positive direction, Vaccine Hesitancy is a global issue. Many infectious disease physicians, epidemiologists, and Public Health Authorities fear that Vaccine Hesitancy will indefinitely prolong the pandemic, as the Delta Variant currently ravages through the unvaccinated population. In an attempt to understand this global phenomenon, we looked at the United States’ vaccine rollout. In particular, we examined the determinants of vaccine hesitancy in the USA. Our empirical model reveals that Vaccine Hesitancy is significantly impacted by factors such as Median Income, Political Affiliation, Percentage of population that is White/Caucasian, Total Cases, Individuals without Health Insurance, and Education level. We use data from all 50 states in the US. Policy makers in other countries can greatly benefit from the findings of our empirical results. Some incentive structures should be introduced as quickly as possible to achieve a high vaccination rate in the country. Our goal is to use the United State’s experience of Vaccine Hesitancy as a baseline of sorts for the greater global community to understand, and reduce hesitancy in their vaccine rollouts.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Cecilia Wolff ◽  
Heidi Lange ◽  
Siri Feruglio ◽  
Line Vold ◽  
Emily MacDonald

Abstract Background In Norway, Legionnaires’ disease is reportable upon clinical suspicion to public health authorities and mandatorily notifiable through the Norwegian surveillance system for communicable diseases (MSIS) for both clinicians and laboratories. In the summer of 2017, several European countries reported high notification rates for Legionnaires’ disease, which was not observed in Norway. We evaluated MSIS to assess if it meets its objectives of detecting cases and trends in incidence of Legionnaires’ disease. Methods We retrieved MSIS data from 2008 to 2017 and calculated timeliness as days from sampling to notification, and internal completeness for key variables as the proportion of observations with a value. Where possible, we assessed internal validity on the presence of a plausible value. To estimate external completeness and validity we linked MSIS with hospital reimbursement claims in the Norwegian Patient Registry. To assess acceptability and representativeness, we surveyed doctors in 39 hospitals on their units’ diagnostic and notification procedures, and their use of MSIS. Results There were 438 notified cases. Internal completeness and internal validity were high for key variables (≥95%). The median delay from sampling to notification was 4 days. There were 73 patients in MSIS only, 70 in the Norwegian Patient Registry only, and 351 in both registers. The external completeness of MSIS was 83% (95% CI 80–86%). For external validity, the positive predictive value of MSIS was 83% (95% CI 79–86%). Forty-seven respondents from 28 hospitals described testing procedures. These were inconsistent: 29 (62%) reported no systematic application of criteria for requesting legionella testing. Eighteen (38%) reported testing all patients with suspected pneumonia and a travel history. Thirty-one (66%) found the notification criteria clear. Conclusions Our results suggest that the surveillance in MSIS can detect incidence changes for Legionnaires’ disease over time, by place and person, but likely does not detect every case diagnosed in Norway. We recommend wider investigation of diagnostic procedures in order to improve representativeness and awareness of MSIS notification criteria among clinicians in order to improve acceptability of the surveillance. We also recommend a more comprehensive assessment of whether patients only registered in the Norwegian Patient Registry were true Legionnaires’ disease cases.


2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Heslley Machado Silva

Abstract Background Scientific denialism has always had harmful consequences for humanity, but with the advent of the pandemic these effects seem to have been accentuated. Main body Unwillingness to accept the facts about the COVID-19 pandemic ascertained by scientists and public health authorities has led to widespread scientific denialism, including the emergence of conspiracy theories of all sorts. Examples are diverse, reaching both developed and developing countries, arriving through populist leaders and the spread of conspiracy theories through social media. Short conclusion It is important to pay attention to the risk of the extremes of this denialism and the possible repercussions, especially in countries that have leaders who agree with these conceptions, such as Brazil and the USA.


2021 ◽  
Vol 104 (4) ◽  
pp. 1493-1494
Author(s):  
Esteban Ortiz-Prado ◽  
Aquiles R. Henriquez-Trujillo ◽  
Ismar A. Rivera-Olivero ◽  
Byron Freire-Paspuel ◽  
Alexander Paolo Vallejo-Janeta ◽  
...  

ABSTRACTRural communities from Latin America are particularly susceptible to develop serious outbreaks of infectious diseases. Inadequate diagnosis and poor health infrastructure jeopardize proper contact tracing and other actions to reduce the impact of COVID-19 in the region. We herein describe the preliminary data of our ongoing fieldwork of massive testing among nonhospitalized rural population in Manabi Province of the coastal region of Ecuador. A total of 1,479 people from six different rural communities were tested for SARS-CoV-2 by RT-qPCR following the CDC protocol; 350 individuals tested positive, resulting in an overall attack rate of 23.7% for SARS-CoV-2 infection. This ultrahigh prevalence must urge to the public health authorities from Ecuador to take immediate actions to counteract this dramatic scenario in Manabi Province and to improve SARS-CoV-2 testing countrywide.


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