Covid-19: Where are we on vaccines and variants?

Mahase, Elisabeth

doi:10.1136/bmj.n597

Cited by 119 publications

(122 citation statements)

References 10 publications

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“…Moreover, we did not assume the British or South African mutation. Not all vaccines might protect from these variants [22–24]. Also these situations can be accommodated by the model.…”

Section: Discussionmentioning

confidence: 99%

The impact of COVID-19 vaccination campaigns accounting for antibody-dependent enhancement

Adil

Obama

Mbeutchou

et al. 2021

Preprint

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BackgroundCOVID-19 vaccines are approved, vaccination campaigns are launched, and worldwide return to normality seems within close reach. Nevertheless, concerns about the safety of COVID-19 vaccines arose, due to their fast emergency approval. In fact, the problem of antibody-dependent enhancement was raised in the context of COVID-19 vaccines.Methods and findingsWe introduce a complex extension of the model underlying the pandemic preparedness tool CovidSim 1.1 (http://covidsim.eu/) to optimize vaccination strategies with regard to the onset of campaigns, vaccination coverage, vaccination schedules, vaccination rates, and efficiency of vaccines. Vaccines are not assumed to immunize perfectly. Some individuals fail to immunize, some reach only partial immunity, and – importantly – some develop antibody-dependent enhancement, which increases the likelihood of developing symptomatic and severe episodes (associated with higher case fatality) upon infection. Only a fraction of the population will be vaccinated, reflecting vaccination hesitancy or contraindications.We parameterized the model to reflect the situation in Germany and predict increasing incidence (and prevalence) in early 2021 followed by a decline by summer. Assuming contact reductions (curfews, social distancing, etc.) to be lifted in summer, disease incidence will peak again. Fast vaccine deployment contributes to reduce disease incidence in the first quarter of 2021, and delay the epidemic outbreak after the summer season. Higher vaccination coverage results in a delayed and reduced epidemic peak. A coverage of 75% – 80% is necessary to prevent an epidemic peak without further drastic contact reductions.ConclusionsWith the vaccine becoming available, compliance with contact reductions is likely to fade. To prevent further economic damage from COVID-19, high levels of immunization need to be reached before next year’s flu season, and vaccination strategies and disease management need to be flexibly adjusted. The predictive model can serve as a refined decision support tool for COVID-19 management.

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“…Moreover, we did not assume the British or South African mutation. Not all vaccines might protect from these variants [22–24]. Also these situations can be accommodated by the model.…”

Section: Discussionmentioning

confidence: 99%

The impact of COVID-19 vaccination campaigns accounting for antibody-dependent enhancement

Adil

Obama

Mbeutchou

et al. 2021

Preprint

View full text Add to dashboard Cite

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“…In this regard, data have been published showing that B.1.1.7 differs in some immunologic characteristics compared to "wild-type" SARS-CoV-2. [67][68][69][70][71][72][73][74] SARS-CoV-2 variants with the E484K amino acid replacement are of particular concern in many areas including Brazil, South Africa, India and elsewhere (https://www.cidrap.umn.edu/news-perspective/2021/02/pfizer-moderna-vaccines-may-be-lesseffective-against-b1351-variant, last accessed: May 17, 2021). Consistent with other studies, we identified the E484K change in several genetically distinct lineages of the virus, a finding likely due to convergent evolution, as noted previously by others.…”

Section: Discussionmentioning

confidence: 99%

Trajectory of Growth of SARS-CoV-2 Variants in Houston, Texas, January through May 2021 Based on 12,476 Genome Sequences

Olsen

Christensen

Long

et al. 2021

Preprint

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Genetic variants of the SARS-CoV-2 virus are of substantial concern because they can detrimentally alter the trajectory of the ongoing pandemic, and disease course in individual patients. Here we report genome sequences from 11,568 COVID-19 patients in the Houston Methodist healthcare system dispersed throughout the metroplex that were diagnosed from January 1, 2021 through April 30, 2021. This sample represents 94% of Houston Methodist cases and 4.6% of all reported cases in the metropolitan area during this period. The SARS-CoV-2 variant designated UK B.1.1.7 increased very rapidly, and now causes 75%-90% of all new cases in the Houston area. Five of the 2,543 B.1.1.7 genomes had an E484K change in spike protein. Compared with non-B.1.1.7 patients, individuals infected with B.1.1.7 had a significantly lower cycle threshold value (considered to be a proxy for higher virus load) and higher rate of hospitalization. Other variants (e.g., B.1.429, B.1.427, P.1, P.2, and R.1) also increased rapidly in frequency, although the magnitude was less than for B.1.1.7. We also identified 42 patients with a recently described R.1 variant that has an E484K amino acid replacement, and seven patients with the B.1.617 "India" variants. In the aggregate, our study shows the occurrence of a diverse array of concerning SARS-CoV-2 variants circulating in a major metropolitan area, documents B.1.1.7 as the major cause of new cases in Houston and heralds the arrival and spread of B.1.617 variants in the metroplex.

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“…Moreover, we did not assume the British or South African mutation. Not all vaccines might protect from these variants [22][23][24]. Also these situations can be accommodated by the model.…”

Section: Plos Onementioning

confidence: 99%

The impact of COVID-19 vaccination campaigns accounting for antibody-dependent enhancement

et al. 2021

View full text Add to dashboard Cite

Background COVID-19 vaccines are approved, vaccination campaigns are launched, and worldwide return to normality seems within close reach. Nevertheless, concerns about the safety of COVID-19 vaccines arose, due to their fast emergency approval. In fact, the problem of antibody-dependent enhancement was raised in the context of COVID-19 vaccines. Methods and findings We introduce a complex extension of the model underlying the pandemic preparedness tool CovidSim 1.1 (http://covidsim.eu/) to optimize vaccination strategies with regard to the onset of campaigns, vaccination coverage, vaccination schedules, vaccination rates, and efficiency of vaccines. Vaccines are not assumed to immunize perfectly. Some individuals fail to immunize, some reach only partial immunity, and—importantly—some develop antibody-dependent enhancement, which increases the likelihood of developing symptomatic and severe episodes (associated with higher case fatality) upon infection. Only a fraction of the population will be vaccinated, reflecting vaccination hesitancy or contraindications. The model is intended to facilitate decision making by exploring ranges of parameters rather than to be fitted by empirical data. We parameterized the model to reflect the situation in Germany and predict increasing incidence (and prevalence) in early 2021 followed by a decline by summer. Assuming contact reductions (curfews, social distancing, etc.) to be lifted in summer, disease incidence will peak again. Fast vaccine deployment contributes to reduce disease incidence in the first quarter of 2021, and delay the epidemic outbreak after the summer season. Higher vaccination coverage results in a delayed and reduced epidemic peak. A coverage of 75%–80% is necessary to prevent an epidemic peak without further drastic contact reductions. Conclusions With the vaccine becoming available, compliance with contact reductions is likely to fade. To prevent further economic damage from COVID-19, high levels of immunization need to be reached before next year’s flu season, and vaccination strategies and disease management need to be flexibly adjusted. The predictive model can serve as a refined decision support tool for COVID-19 management.

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Covid-19: Where are we on vaccines and variants?

Abstract: Nearly a year after WHO declared the covid-19 pandemic, Elisabeth Mahase reports on the latest developments in vaccines, variants, and diplomacy

Cited by 119 publications

References 10 publications

The impact of COVID-19 vaccination campaigns accounting for antibody-dependent enhancement

The impact of COVID-19 vaccination campaigns accounting for antibody-dependent enhancement

Trajectory of Growth of SARS-CoV-2 Variants in Houston, Texas, January through May 2021 Based on 12,476 Genome Sequences

The impact of COVID-19 vaccination campaigns accounting for antibody-dependent enhancement

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