Background
The ChAdOx1 nCoV-19 (AZD1222) vaccine has been approved for emergency use by the UK regulatory authority, Medicines and Healthcare products Regulatory Agency, with a regimen of two standard doses given with an interval of 4–12 weeks. The planned roll-out in the UK will involve vaccinating people in high-risk categories with their first dose immediately, and delivering the second dose 12 weeks later. Here, we provide both a further prespecified pooled analysis of trials of ChAdOx1 nCoV-19 and exploratory analyses of the impact on immunogenicity and efficacy of extending the interval between priming and booster doses. In addition, we show the immunogenicity and protection afforded by the first dose, before a booster dose has been offered.
Methods
We present data from three single-blind randomised controlled trials—one phase 1/2 study in the UK (COV001), one phase 2/3 study in the UK (COV002), and a phase 3 study in Brazil (COV003)—and one double-blind phase 1/2 study in South Africa (COV005). As previously described, individuals 18 years and older were randomly assigned 1:1 to receive two standard doses of ChAdOx1 nCoV-19 (5 × 10
10
viral particles) or a control vaccine or saline placebo. In the UK trial, a subset of participants received a lower dose (2·2 × 10
10
viral particles) of the ChAdOx1 nCoV-19 for the first dose. The primary outcome was virologically confirmed symptomatic COVID-19 disease, defined as a nucleic acid amplification test (NAAT)-positive swab combined with at least one qualifying symptom (fever ≥37·8°C, cough, shortness of breath, or anosmia or ageusia) more than 14 days after the second dose. Secondary efficacy analyses included cases occuring at least 22 days after the first dose. Antibody responses measured by immunoassay and by pseudovirus neutralisation were exploratory outcomes. All cases of COVID-19 with a NAAT-positive swab were adjudicated for inclusion in the analysis by a masked independent endpoint review committee. The primary analysis included all participants who were SARS-CoV-2 N protein seronegative at baseline, had had at least 14 days of follow-up after the second dose, and had no evidence of previous SARS-CoV-2 infection from NAAT swabs. Safety was assessed in all participants who received at least one dose. The four trials are registered at ISRCTN89951424 (COV003) and
ClinicalTrials.gov
,
NCT04324606
(COV001),
NCT04400838
(COV002), and
NCT04444674
(COV005).
Findings
Between April 23 and Dec 6, 2020, 24 422 participants were recruited and vaccinated across the four studies, of whom 17 178 were included in the primary analysis (8597 receiving ChAdOx1 nCoV-19 and 8581 receiving control vaccine). The data cutoff for these analyses was Dec 7, 2020. 332 NAAT-positive infections met the primary endpoint of symptomatic infection more t...
Summary
Purpose
Autoantibodies to specific neurologic proteins are associated with subacute onset encephalopathies, which often present with seizures that are poorly controlled by conventional antiepileptic drugs (AEDs). Previous cross‐sectional studies have found specific neurologic antibodies in a small proportion of people with established epilepsy, but these investigations have seldom included patients with recent diagnosis.
Methods
We screened two large epilepsy cohorts to investigate the prevalence of multiple autoantibodies in adult patients with either established or newly diagnosed, untreated epilepsy.
Key Findings
Eleven percent of patients had antibodies to one or more antigen: voltage‐gated potassium channel (VGKC) complex proteins (5%), glycine receptors (3%), and glutamic acid decarboxylase (GAD) and N‐methyl‐d‐aspartate (NMDA) receptors (1.7% each). There was no difference in the prevalence of antibodies, individually or collectively, between patients with established and newly diagnosed epilepsy or with generalized or focal epilepsy. There was, however, a significantly higher prevalence of positive antibody titers in patients with focal epilepsy of unknown cause than in those with structural/metabolic focal epilepsy (14.8% vs. 6.3%; p < 0.02). Newly diagnosed antibody‐positive patients were less likely to achieve adequate seizure control with initial treatment than antibody‐negative patients, but this difference failed to reach statistical significance.
Significance
The presence of autoantibodies is equally common in newly diagnosed and established epilepsy, it is therefore unlikely to be an epiphenomenon of long‐standing refractory seizures.
Encephalitis associated with VGKC Ab occurs in children and presents with status epilepticus and focal epilepsy. These antibodies are not directed against Lgi1 or Caspr2.
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