Safety and immunogenicity of a variant-adapted SARS-CoV-2 recombinant protein vaccine with AS03 adjuvant as a booster in adults primed with authorized vaccines: a phase 3, parallel-group study

Background

In a parallel-group, international, phase 3 study (ClinicalTrials.govNCT04762680), we evaluated prototype (D614) and Beta (B.1.351) variant recombinant spike protein booster vaccines with AS03-adjuvant (CoV2 preS dTM-AS03).

Methods

Adults, previously primed with mRNA (BNT162b2, mRNA-1273), adenovirus-vectored (Ad26.CoV2.S, ChAdOx1nCoV-19) or protein (CoV2 preS dTM-AS03 [monovalent D614; MV(D614)]) vaccines were enrolled between 29 July 2021 and 22 February 2022. Participants were stratified by age (18-55 and ≥ 56 years) and received one of the following CoV2 preS dTM-AS03 booster formulations: MV(D614) (n = 1285), MV(B.1.351) (n = 707) or bivalent D614 + B.1.351 (BiV; n = 625). Unvaccinated adults who tested negative on a SARS-CoV-2 rapid diagnostic test (control group, n = 479) received two primary doses, 21 days apart, of MV(D614). Anti-D614G and anti-B.1.351 antibodies were evaluated using validated pseudovirus (lentivirus) neutralization (PsVN) assay 14 days post-booster (day [D]15) in 18-55-year-old BNT162b2-primed participants and compared with those pre-booster (D1) and on D36 in 18-55-year-old controls (primary immunogenicity endpoints). PsVN titers to Omicron BA.1, BA.2 and BA.4/5 subvariants were also evaluated. Safety was evaluated over a 12-month follow-up period. Planned interim analyses are presented up to 14 days post-last vaccination for immunogenicity and over a median duration of 5 months for safety.

Findings

All three boosters elicited robust anti-D614G or -B.1.351 PsVN responses for mRNA, adenovirus-vectored and protein vaccine-primed groups. Among BNT162b2-primed adults (18-55 years), geometric means of the individual post-booster versus pre-booster titer ratio (95% confidence interval [CI]) were: for MV (D614), 23.37 (18.58-29.38) (anti-D614G); for MV(B.1.351), 35.41 (26.71-46.95) (anti-B.1.351); and for BiV, 14.39 (11.39-18.28) (anti-D614G) and 34.18 (25.84-45.22 (anti-B.1.351). GMT ratios (98.3% CI) versus post-primary vaccination GMTs in controls, were: for MV(D614) booster, 2.16 (1.69; 2.75) [anti-D614G]; for MV(B.1.351), 1.96 (1.54; 2.50) [anti-B.1.351]; and for BiV, 2.34 (1.84; 2.96) [anti-D614G] and 1.39 (1.09; 1.77) [anti-B.1.351]. All booster formulations elicited cross-neutralizing antibodies against Omicron BA.2 (across priming vaccine subgroups), Omicron BA.1 (BNT162b2-primed participants) and Omicron BA.4/5 (BNT162b2-primed participants and MV D614-primed participants). Similar patterns in antibody responses were observed for participants aged ≥56 years. Reactogenicity tended to be transient and mild-to-moderate severity in all booster groups. No safety concerns were identified.

Interpretation

CoV2 preS dTM-AS03 boosters demonstrated acceptable safety and elicited robust neutralizing antibodies against multiple variants, regardless of priming vaccine.

Funding

Sanofi and Biomedical Advanced Research and Development Authority (BARDA).

Evaluation of clinical case definitions for respiratory syncytial virus lower respiratory tract infection in young children

BACKGROUND

Various case definitions of respiratory syncytial virus lower respiratory tract infection (RSV-LRTI) are currently proposed. We assessed the performance of three clinical case definitions against the World Health Organization definition recommended in 2015 (WHO 2015).

METHODS

In this prospective cohort study conducted in eight countries, 2401 children were followed up during 2 years from birth. Suspected LRTIs were detected via active and passive surveillance, followed by in-person clinical evaluation including single timepoint respiratory rate and oxygen saturation (by pulse oximetry) assessment, and nasopharyngeal sampling for RSV testing by polymerase chain reaction. Agreement between case definitions was evaluated using Cohen's κ statistics.

RESULTS

Of 1652 suspected LRTIs, 227 met the WHO 2015 criteria for RSV-LRTI; 73 were classified as severe. All alternative definitions were highly concordant with the WHO 2015 definition for RSV-LRTI (κ: 0.95-1.00), but less concordant for severe RSV-LRTI (κ: 0.47-0.82). Tachypnea was present for 196/226 (86.7%) WHO 2015 RSV-LRTIs and 168/243 (69.1%) LRTI/bronchiolitis/pneumonia cases, clinically diagnosed by non-study physicians. Low oxygen saturation levels were observed in only 55/226 (24.3%) WHO 2015 RSV-LRTIs.

CONCLUSION

Three case definitions for RSV-LRTI showed high concordance with the WHO 2015 definition, while agreement was lower for severe RSV-LRTI. In contrast to increased respiratory rate, low oxygen saturation was not a consistent finding in RSV-LRTIs and severe RSV-LRTIs. This study demonstrates that current definitions are highly concordant for RSV-LRTIs, but a standard definition is still needed for severe RSV-LRTI.

Incidence of respiratory syncytial virus lower respiratory tract infections during the first 2 years of life: A prospective study across diverse global settings

Background

The true burden of lower respiratory tract infections (LRTIs) due to respiratory syncytial virus (RSV) remains unclear. This study aimed to provide more robust, multinational data on RSV-LRTI incidence and burden in the first 2 years of life.

Methods

This prospective, observational cohort study was conducted in Argentina, Bangladesh, Canada, Finland, Honduras, South Africa, Thailand, and United States. Children were followed for 24 months from birth. Suspected LRTIs were detected via active (through regular contacts) and passive surveillance. RSV and other viruses were detected from nasopharyngeal swabs using PCR-based methods.

Results

Of 2401 children, 206 (8.6%) had 227 episodes of RSV-LRTI. Incidence rates (IRs) of first episode of RSV-LRTI were 7.35 (95% confidence interval [CI], 5.88–9.08), 5.50 (95% CI, 4.21–7.07), and 2.87 (95% CI, 2.18–3.70) cases/100 person-years in children aged 0–5, 6–11, and 12–23 months. IRs for RSV-LRTI, severe RSV-LRTI, and RSV hospitalization tended to be higher among 0–5 month olds and in lower-income settings. RSV was detected for 40% of LRTIs in 0–2 month olds and for approximately 20% of LRTIs in older children. Other viruses were codetected in 29.2% of RSV-positive nasopharyngeal swabs.

Conclusions

A substantial burden of RSV-LRTI was observed across diverse settings, impacting the youngest infants the most.

Clinical Trials Registration. NCT01995175.

Safety and immunogenicity of an AS03-adjuvanted SARS-CoV-2 recombinant protein vaccine (CoV2 preS dTM) in healthy adults: interim findings from a phase 2, randomised, dose-finding, multicentre study

BACKGROUND

We evaluated our SARS-CoV-2 prefusion spike recombinant protein vaccine (CoV2 preS dTM) with different adjuvants, unadjuvanted, and in a one-injection and two-injection dosing schedule in a previous phase 1-2 study. Based on interim results from that study, we selected a two-injection schedule and the AS03 adjuvant for further clinical development. However, lower than expected antibody responses, particularly in older adults, and higher than expected reactogenicity after the second vaccination were observed. In the current study, we evaluated the safety and immunogenicity of an optimised formulation of CoV2 preS dTM adjuvanted with AS03 to inform progression to phase 3 clinical trial.

METHODS

This phase 2, randomised, parallel-group, dose-ranging study was done in adults (≥18 years old), including those with pre-existing medical conditions, those who were immunocompromised (except those with recent organ transplant or chemotherapy) and those with a potentially increased risk for severe COVID-19, at 20 clinical research centres in the USA and Honduras. Women who were pregnant or lactating or, for those of childbearing potential, not using an effective method of contraception or abstinence, and those who had received a COVID-19 vaccine, were excluded. Participants were randomly assigned (1:1:1) using an interactive response technology system, with stratification by age (18-59 years and ≥60 years), rapid serodiagnostic test result (positive or negative), and high-risk medical conditions (yes or no), to receive two injections (day 1 and day 22) of 5 7mu;g (low dose), 10 7mu;g (medium dose), or 15 7mu;g (high dose) CoV2 preS dTM antigen with fixed AS03 content. All participants and outcome assessors were masked to group assignment; unmasked study staff involved in vaccine preparation were not involved in safety outcome assessments. All laboratory staff performing the assays were masked to treatment. The primary safety objective was to describe the safety profile in all participants, for each candidate vaccine formulation. Safety endpoints were evaluated for all randomised participants who received at least one dose of the study vaccine (safety analysis set), and are presented here for the interim study period (up to day 43). The primary immunogenicity objective was to describe the neutralising antibody titres to the D614G variant 14 days after the second vaccination (day 36) in participants who were SARS-CoV-2 naive who received both injections, provided samples at day 1 and day 36, did not have protocol deviations, and did not receive an authorised COVID-19 vaccine before day 36. Neutralising antibodies were measured using a pseudovirus neutralisation assay and are presented here up to 14 days after the second dose. As a secondary immunogenicity objective, we assessed neutralising antibodies in non-naive participants. This trial is registered with ClinicalTrials.gov (NCT04762680) and is closed to new participants for the cohort reported here.

FINDINGS

Of 722 participants enrolled and randomly assigned between Feb 24, 2021, and March 8, 2021, 721 received at least one injection (low dose=240, medium dose=239, and high dose=242). The proportion of participants reporting at least one solicited adverse reaction (injection site or systemic) in the first 7 days after any vaccination was similar between treatment groups (217 [91%] of 238 in the low-dose group, 213 [90%] of 237 in the medium-dose group, and 218 [91%] of 239 in the high-dose group); these adverse reactions were transient, were mostly mild to moderate in intensity, and occurred at a higher frequency and intensity after the second vaccination. Four participants reported immediate unsolicited adverse events; two (one each in the low-dose group and medium-dose group) were considered by the investigators to be vaccine related and two (one each in the low-dose and high-dose groups) were considered unrelated. Five participants reported seven vaccine-related medically attended adverse events (two in the low-dose group, one in the medium-dose group, and four in the high-dose group). No vaccine-related serious adverse events and no adverse events of special interest were reported. Among participants naive to SARS-CoV-2 at day 36, 158 (98%) of 162 in the low-dose group, 166 (99%) of 168 in the medium-dose group, and 163 (98%) of 166 in the high-dose group had at least a two-fold increase in neutralising antibody titres to the D614G variant from baseline. Neutralising antibody geometric mean titres (GMTs) at day 36 for participants who were naive were 2189 (95% CI 1744-2746) for the low-dose group, 2269 (1792-2873) for the medium-dose group, and 2895 (2294-3654) for the high-dose group. GMT ratios (day 36: day 1) were 107 (95% CI 85-135) in the low-dose group, 110 (87-140) in the medium-dose group, and 141 (111-179) in the high-dose group. Neutralising antibody titres in non-naive adults 21 days after one injection tended to be higher than titres after two injections in adults who were naive, with GMTs 21 days after one injection for participants who were non-naive being 3143 (95% CI 836-11 815) in the low-dose group, 2338 (593-9226) in the medium-dose group, and 7069 (1361-36 725) in the high-dose group.

INTERPRETATION

Two injections of CoV2 preS dTM-AS03 showed acceptable safety and reactogenicity, and robust immunogenicity in adults who were SARS-CoV-2 naive and non-naive. These results supported progression to phase 3 evaluation of the 10 7mu;g antigen dose for primary vaccination and a 5 7mu;g antigen dose for booster vaccination.

FUNDING

Sanofi Pasteur and Biomedical Advanced Research and Development Authority.

Immunogenicity and Reactogenicity of an Inactivated Quadrivalent Influenza Vaccine Administered Intramuscularly to Children 6 to 35 Months of Age in 2012-2013: A Randomized, Double-Blind, Controlled, Multicenter, Multicountry, Clinical Trial

BACKGROUND

Influenza attack rates are high in 6- to 35-month-old children; vaccines containing both lineages of influenza B (Yamagata and Victoria), in addition to the H3N2 and H1N1 antigens, may improve protection rates.

METHODS

In a randomized double-blind controlled trial, the immunogenicity and reactogenicity of an inactivated quadrivalent influenza vaccine (QIV) and a trivalent control vaccine (TIV) were assessed.

RESULTS

Six hundred one children (QIV, n = 299; TIV, n = 302) were enrolled at 8 sites in 3 countries. The primary immunogenicity objective was met: the lower limit (LL) of the 2-sided 95% confidence interval (CI) for the seroconversion rate in QIV recipients ranged from 66.6% to 81.3%, which was ≥40% against all 4 strains. The immunogenic superiority of the additional B/Victoria strain in the QIV compared to that in the TIV was confirmed: the LL of the 2-sided 95% CI of the geometric mean titer ratio (QIV/TIV) (6.28 [95% CI, 5.32-7.41]) was greater than 1.5, and the LL of the 2-sided 95% CI for the difference in the seroconversion rate (QIV - TIV) (64.19% [95% CI, 57.65%-69.95%]) was greater than 10%. Injection-site pain and irritability/fussiness were the most commonly reported solicited injection-site and general adverse events, respectively, from days 0 to 6 and were similar in frequency between the groups.

CONCLUSIONS

In children aged 6 to 35 months, a QIV has superior immunogenicity for the added B strain and acceptable immunogenicity for shared strains, with no notable difference in reactogenicity and safety when compared to a TIV.

Lead toxicity and endoscopic removal of ingested firearm cartridges

CONTEXT

Lead toxicity from the ingestion of a lead foreign body has been described in several case reports. Management of ingested live ammunition presents its own challenges due to the risk of accidental discharge. A safe and effective method of retrieving a live cartridge must be considered.

CASE DETAILS

We present two cases of lead toxicity due to intact firearm cartridge ingestion with the removal of the cartridges via endoscopy. The first case is of severe pediatric lead toxicity due to the ingestion of 30-mm rifle cartridges. The second case is an adult ingestion of .22 caliber cartridges resulting in mild lead toxicity.

DISCUSSION

These cases illustrate a diagnostic dilemma in both the diagnosis of lead toxicity and the removal of live ammunition from the stomach.

Poverty-associated risk factors for wheezing in the first year of life in Honduras and El Salvador

BACKGROUND

Risk factors for wheezing specifically during the first year of life have been studied in well-developed countries, but the information from developing countries is very scarce. There are no such studies focusing on factors derived from poverty. The aim of the present study was to determine if risk factors related to poverty are associated to wheezing during the first year of life in infants from Honduras and El Salvador.

METHODS

A survey, using a validated questionnaire, was carried out in the metropolitan area of San Pedro Sula (Honduras) and in La Libertad (El Salvador) in centres where infants attended for a scheduled vaccination shot or a healthy child visit at 12 months of age. Fieldworkers offered questionnaires to parents and helped the illiterate when necessary. The main outcome variable was wheezing during the first year of life, as reported by parents.

RESULTS

A total of 1047 infants in El Salvador and 780 in Honduras were included in the analysis. The prevalence of wheeze in the first year was higher in El Salvador (41.2%) than in Honduras (27.7%), as was recurrent wheezing defined as three or more episodes (18.4% vs. 11.7%). Wheezing and recurrent wheezing was associated to unpaved floor in the household (summary odds ratios for both countries 1.55, p=0.036 and 1.72, p=0.054 for any wheeze and recurrent wheezing, respectively); dust entering from streets (1.30, p=0.052 and 1.67, p=0.008); living in a heavily polluted area (1.33, p=0.037 and 1.52, p=0.033); and having mould stains on the household walls (1.36, p=0.072 and 1.76, p=0.007). Furthermore, marginal associations were found for additional person at home and use of kerosene as cooking fuel. University studies in the mother (0.34, p=0.046 and 0.32, p=0.022) and a professional occupation in the father (0.34, p=0.046 and 0.26, p=0.047) were associated to a lower risk.

CONCLUSIONS

The prevalence of wheezing and recurrent wheezing is notoriously high in El Salvador and Honduras. In those populations factors related to poverty are associated to a higher prevalence of wheezing and recurrent wheezing, whereas higher maternal education and paternal professional occupation behave as protective factors.

[A phonogramic study of expiratory wheezing in the asthmatic patient]

The quantitative analysis of expiratory wheezing may offer a new approach for study respiratory function in asthmatics.

METHOD

The sound spectrum during expiration was analyzed in 9 asthmatics with wheezing and 5 normal subjects. Phonographic parameters were then correlated with spirometric results for baseline respiration and deep breathing.

RESULTS

a) Expiratory wheezing is heard in a band of 210 to 280 Hz during deep breathing, and b) the volume in this band correlates positively with mean expiratory flow (VT/TE) and negatively with the slope of the volume/flow curve between 50 and 25% of FVC.

CONCLUSIONS

The degree of air flow limitation in the peripheral airways correlates with the volume of pulmonary sound.

Pulmonary thromboembolism associated with superior vena cava thrombosis following permanent transvenous endocardial cardiac pacing

The case of a 70 year old man with superior vena cava syndrome associated with transvenous pacemaker electrode and a 2 yr history of right ventricular failure is reported. Digital subtraction angiography demonstrated a major thrombus in the right pulmonary artery, and pulmonary thromboembolism was confirmed.