1.
Nirsevimab binding-site conservation in respiratory syncytial virus fusion glycoprotein worldwide between 1956 and 2021: an analysis of observational study sequencing data.
Wilkins, D, Langedijk, AC, Lebbink, RJ, Morehouse, C, Abram, ME, Ahani, B, Aksyuk, AA, Baraldi, E, Brady, T, Chen, AT, et al
The Lancet. Infectious diseases. 2023;(7):856-866
Abstract
BACKGROUND Nirsevimab is an extended half-life monoclonal antibody to the respiratory syncytial virus (RSV) fusion protein that has been developed to protect infants for an entire RSV season. Previous studies have shown that the nirsevimab binding site is highly conserved. However, investigations of the geotemporal evolution of potential escape variants in recent (ie, 2015-2021) RSV seasons have been minimal. Here, we examine prospective RSV surveillance data to assess the geotemporal prevalence of RSV A and B, and functionally characterise the effect of the nirsevimab binding-site substitutions identified between 2015 and 2021. METHODS We assessed the geotemporal prevalence of RSV A and B and nirsevimab binding-site conservation between 2015 and 2021 from three prospective RSV molecular surveillance studies (the US-based OUTSMART-RSV, the global INFORM-RSV, and a pilot study in South Africa). Nirsevimab binding-site substitutions were assessed in an RSV microneutralisation susceptibility assay. We contextualised our findings by assessing fusion-protein sequence diversity from 1956 to 2021 relative to other respiratory-virus envelope glycoproteins using RSV fusion protein sequences published in NCBI GenBank. FINDINGS We identified 5675 RSV A and RSV B fusion protein sequences (2875 RSV A and 2800 RSV B) from the three surveillance studies (2015-2021). Nearly all (25 [100%] of 25 positions of RSV A fusion proteins and 22 [88%] of 25 positions of RSV B fusion proteins) amino acids within the nirsevimab binding site remained highly conserved between 2015 and 2021. A highly prevalent (ie, >40·0% of all sequences) nirsevimab binding-site Ile206Met:Gln209Arg RSV B polymorphism arose between 2016 and 2021. Nirsevimab neutralised a diverse set of recombinant RSV viruses, including new variants containing binding-site substitutions. RSV B variants with reduced susceptibility to nirsevimab neutralisation were detected at low frequencies (ie, prevalence <1·0%) between 2015 and 2021. We used 3626 RSV fusion-protein sequences published in NCBI GenBank between 1956 and 2021 (2024 RSV and 1602 RSV B) to show that the RSV fusion protein had lower genetic diversity than influenza haemagglutinin and SARS-CoV-2 spike proteins. INTERPRETATION The nirsevimab binding site was highly conserved between 1956 and 2021. Nirsevimab escape variants were rare and have not increased over time. FUNDING AstraZeneca and Sanofi.
2.
Efficacy of the adjuvanted subunit protein COVID-19 vaccine, SCB-2019: a phase 2 and 3 multicentre, double-blind, randomised, placebo-controlled trial.
Bravo, L, Smolenov, I, Han, HH, Li, P, Hosain, R, Rockhold, F, Clemens, SAC, Roa, C, Borja-Tabora, C, Quinsaat, A, et al
Lancet (London, England). 2022;(10323):461-472
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Abstract
BACKGROUND A range of safe and effective vaccines against SARS CoV 2 are needed to address the COVID 19 pandemic. We aimed to assess the safety and efficacy of the COVID-19 vaccine SCB-2019. METHODS This ongoing phase 2 and 3 double-blind, placebo-controlled trial was done in adults aged 18 years and older who were in good health or with a stable chronic health condition, at 31 sites in five countries (Belgium, Brazil, Colombia, Philippines, and South Africa). The participants were randomly assigned 1:1 using a centralised internet randomisation system to receive two 0·5 mL intramuscular doses of SCB-2019 (30 μg, adjuvanted with 1·50 mg CpG-1018 and 0·75 mg alum) or placebo (0·9% sodium chloride for injection supplied in 10 mL ampoules) 21 days apart. All study staff and participants were masked, but vaccine administrators were not. Primary endpoints were vaccine efficacy, measured by RT-PCR-confirmed COVID-19 of any severity with onset from 14 days after the second dose in baseline SARS-CoV-2 seronegative participants (the per-protocol population), and the safety and solicited local and systemic adverse events in the phase 2 subset. This study is registered on EudraCT (2020-004272-17) and ClinicalTrials.gov (NCT04672395). FINDINGS 30 174 participants were enrolled from March 24, 2021, until the cutoff date of Aug 10, 2021, of whom 30 128 received their first assigned vaccine (n=15 064) or a placebo injection (n=15 064). The per-protocol population consisted of 12 355 baseline SARS-CoV-2-naive participants (6251 vaccinees and 6104 placebo recipients). Most exclusions (13 389 [44·4%]) were because of seropositivity at baseline. There were 207 confirmed per-protocol cases of COVID-19 at 14 days after the second dose, 52 vaccinees versus 155 placebo recipients, and an overall vaccine efficacy against any severity COVID-19 of 67·2% (95·72% CI 54·3-76·8), 83·7% (97·86% CI 55·9-95·4) against moderate-to-severe COVID-19, and 100% (97·86% CI 25·3-100·0) against severe COVID-19. All COVID-19 cases were due to virus variants; vaccine efficacy against any severity COVID-19 due to the three predominant variants was 78·7% (95% CI 57·3-90·4) for delta, 91·8% (44·9-99·8) for gamma, and 58·6% (13·3-81·5) for mu. No safety issues emerged in the follow-up period for the efficacy analysis (median of 82 days [IQR 63-103]). The vaccine elicited higher rates of mainly mild-to-moderate injection site pain than the placebo after the first (35·7% [287 of 803] vs 10·3% [81 of 786]) and second (26·9% [189 of 702] vs 7·4% [52 of 699]) doses, but the rates of other solicited local and systemic adverse events were similar between the groups. INTERPRETATION Two doses of SCB-2019 vaccine plus CpG and alum provides notable protection against the entire severity spectrum of COVID-19 caused by circulating SAR-CoV-2 viruses, including the predominating delta variant. FUNDING Clover Biopharmaceuticals and the Coalition for Epidemic Preparedness Innovations.
3.
Topical versus systemic antibiotics for chronic suppurative otitis media.
Chong, LY, Head, K, Webster, KE, Daw, J, Richmond, P, Snelling, T, Bhutta, MF, Schilder, AG, Burton, MJ, Brennan-Jones, CG
The Cochrane database of systematic reviews. 2021;(2):CD013053
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Abstract
BACKGROUND Chronic suppurative otitis media (CSOM), sometimes referred to as chronic otitis media (COM), is a chronic inflammation and often polymicrobial infection (involving more than one micro-organism) of the middle ear and mastoid cavity, characterised by ear discharge (otorrhoea) through a perforated tympanic membrane. The predominant symptoms of CSOM are ear discharge and hearing loss. Antibiotics are the most common treatment for CSOM, which act to kill or inhibit the growth of micro-organisms that may be responsible for the infection. Antibiotics can be administered both topically and systemically, and can be used alone or in addition to other treatments for CSOM such as ear cleaning (aural toileting). OBJECTIVES To assess the effects of topical versus systemic antibiotics for people with CSOM. SEARCH METHODS The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL via the Cochrane Register of Studies); Ovid MEDLINE; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 16 March 2020. SELECTION CRITERIA We included randomised controlled trials (RCTs) with at least a one-week follow-up involving patients (adults and children) who had chronic ear discharge of unknown cause or CSOM, where the ear discharge had continued for more than two weeks. The studies compared topical antibiotics against systemic (oral, injection) antibiotics. We separated studies according to whether they compared the same type of antibiotic in both treatment groups, or different types of antibiotics. For each comparison we considered whether there was background treatment for both treatment groups, for example aural toileting (ear cleaning). DATA COLLECTION AND ANALYSIS We used the standard Cochrane methodological procedures. We used GRADE to assess the certainty of the evidence for each outcome. Our primary outcomes were: resolution of ear discharge or 'dry ear' (whether otoscopically confirmed or not, measured at between one week and up to two weeks, two weeks up to four weeks, and after four weeks), health-related quality of life using a validated instrument, ear pain (otalgia) or discomfort or local irritation. Secondary outcomes included hearing, serious complications and ototoxicity measured in several ways. MAIN RESULTS Six studies (445 participants), all with high risk of bias, were included. All but two studies included patients with confirmed CSOM, where perforation of the ear drum was clearly documented. None of the studies reported results for resolution of ear discharge after four weeks or health-related quality of life. 1. Topical versus systemic administration of the same type of antibiotics (quinolones) Four studies (325 participants) compared topical versus systemic (oral) administration of ciprofloxacin. Three studies reported resolution of ear discharge at one to two weeks and found that the topical administration may slightly increase resolution (risk ratio (RR) 1.48, 95% confidence interval (CI) 1.24 to 1.76; 285 participants; 3 studies; I2 = 0%; low-certainty evidence). In these studies, aural toileting was either not mentioned, or limited to the first visit. Three studies (265 participants) reported that they did not suspect ototoxicity in any participants, but it is unclear how this was measured (very low-certainty evidence). No studies reported the outcomes of ear pain or serious complications. No studies reported results for hearing, despite it being measured in three studies. 2. Topical versus systemic administration of different types of antibiotics (quinolones versus aminoglycosides) One study (60 participants) compared topical ciprofloxacin versus gentamicin injected intramuscularly. No aural toileting was reported. Resolution of ear discharge was not measured at one to two weeks. The study did not report any 'side effects' from which we assumed that no ear pain, suspected ototoxicity or serious complications occurred (very low-certainty evidence). The study stated that "no worsening of the audiometric function related to local or parenteral therapy was observed". 3. Topical versus systemic administration of different types of antibiotics (quinolones versus amoxicillin-clavulanic acid) One study compared topical ofloxacin with amoxicillin-clavulanic acid with all participants receiving suction ear cleaning at the first visit. It is uncertain if there is a difference between the two groups in resolution of ear discharge at one to two weeks due to study limitations and the very small sample size (RR 2.93, 95% CI 1.50 to 5.72; 56 participants; very low-certainty evidence). It is unclear if there is a difference between topical quinolone compared with oral amoxicillin-clavulanic acid with regards to ear pain, hearing or suspected ototoxicity (very low-certainty evidence). No studies reported the outcome of serious complications. AUTHORS' CONCLUSIONS There was a limited amount of low-quality evidence available, from studies completed over 15 years ago, to examine whether topical or systemic antibiotics are more effective in achieving resolution of ear discharge for people with CSOM. However, amongst this uncertainty there is some evidence to suggest that the topical administration of antibiotics may be more effective than systemic administration of antibiotics in achieving resolution of ear discharge (dry ear). There is limited evidence available regarding different types of antibiotics. It is not possible to determine with any certainty whether or not topical quinolones are better or worse than systemic aminoglycosides. These two groups of compounds have different adverse effect profiles, but there is insufficient evidence from the included studies to make any comment about these. In general, adverse effects were poorly reported.