coronastream: votes, vaccines and variants

posted on march 19, 2021   by dr tim inglis

in this special blog series, medical microbiologists led by dr tim inglis summarise some of the research that will be essential to inform covid-19 countermeasures. find out more about the project in dr inglis' editorial 'logic in the time of coronavirus', published in the journal of medical microbiology

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as predicted in a 2020 retrospective, politicians who cast themselves in the mantle of ‘covid protector’ will do well, and so it proved in western australia where the governing party returned this month with a record-breaking majority. it was a one-issue election – held the same month as vaccinations began locally. readers in less physically isolated parts of the world may interpret these events with a measure of cynicism, but might gain some locally applicable insight from hong and colleagues' analysis of social mobilisation and polarisation in the usa.
the vaccination programme has even reached these distant shores, where the pfizer-biontech vaccine was rolled out. recent difficulties importing the astrazeneca vaccine and questions about its efficacy against variants of concern (voc) may have slowed the national rollout and increased the risk of missing the original vaccination target completion date. ambivalence and, in some cases, frank opposition to covid-19 vaccination from some global leaders has been a source of frustration to everyone engaged in the largest vaccine programme yet.

congruence: variant of concern sensitivity to vaccination

sensitivity of sars-cov-2 b.1.1.7 to mrna vaccine-elicited antibodies
this paper describes the use of pseudoviruses expressing wild type and b.1.1.7 variant spike protein to investigate neutralising antibody responses to the first and second doses of the mrna-based bnt162b2 vaccine. a range of neutralising antibody titres was found to the wild-type spike protein, with a modest reduction in antibody response to the b.1.1.7 variant. introduction of the e484k mutation to b.1.1.7, similar to a new voc; 202102/02, led to further reduction of neutralising activity by vaccine-elicited antibodies over the b.1.1.7 only mutations. the authors conclude that "e484k emergence on a b.1.1.7 background represents a threat to the vaccine bnt162b."
 

consistency: covid-19 in pregnancy

adverse pregnancy outcomes among individuals with and without severe acute respiratory syndrome coronavirus 2 (sars-cov-2): a systematic review and meta-analysis

there has been ongoing concern about fetal risk of sars-cov-2 infection during pregnancy. here huntley and colleagues report their systematic review of studies into covid during pregnancy. the six studies reviewed each reported over 20 individuals, and covered 728 deliveries to sars-cov-2 positive mothers and 3,836 deliveries to sars-cov-2 mothers. intrauterine death occurred in 1.1% sars-cov-2 positive, and 1.1% negative cases. neonatal death occurred in no sars-cov-2 cases and five (0.2%) negatives cases. preterm births occurred in 13.3% positive, and 11.9% negative cases, and maternal deaths occurred in 0.5% and 0.3%, respectively. the authors conclude that "the incidences of intrauterine fetal death and neonatal death were similar among individuals who tested positive compared with negative for sars-cov-2 when admitted to labor and delivery."

cumulative dissonance: alternative cell binding sites

biological and clinical consequences of integrin binding via a rogue rgd motif in the sars cov-2 spike protein

this study draws attention to an alternative pathway for sars-cov-2 spike protein binding to cell surfaces via integrin. recognition of secondary binding sites should help future vaccine design. this also serves as a timely reminder not to put all our eggs in the spike glycoprotein basket.

curtailment: disruption of pandemic controls

social mobilization and polarization can create volatility in covid‑19 pandemic control

the different epidemic trajectories of covid-19 in different countries cannot be explained without examining social, cultural and political factors. hong and colleagues have taken a close look at social mobilisation and polarisation in the usa during the pandemic in order to understand the dynamics of pandemic development there. this is not comfortable reading for anyone who has had to live through the experience. nevertheless, the geographic distribution of polarisation and its correlation with pandemic experience holds lessons for those who are willing to consider what might be required to prevent anything like this from happening again. for those currently living in less covid-encumbered locations, who benefit from risk-adept leadership, there are useful insights in how social mobilisation around public health interventions can create its own set of problems. in particular, their findings highlight social mobilisation as a collective precaution and a potential threat to countermeasures.

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