Humoral immunogenicity and tolerability of heterologous ChAd/BNT compared with homologous BNT/BNT and ChAd/ChAd SARS-CoV-2 vaccination in hemodialysis patients : A multicenter prospective observational study.

After the reports of severe adverse reactions to the AstraZeneca ChAdOx1-S-nCoV-19 vaccine, patients who had received one dose of ChAdOx1-S-nCoV-19 vaccine were recommended a second dose of Pfizer's BNT162b2 vaccine. In hemodialysis patients, we compared the humoral immunogenicity and tolerability of homologous vaccination with ChAdOx1-nCoV-19/ChAdOx1-nCoV-19 (ChAd/ChAd) and BNT162b2/BNT162b2 (BNT/BNT) with heterologous vaccination of first dose of ChAdOx1-nCoV-19 and a second dose with BNT162b2 (ChAd/BNT). In a multicenter prospective observational study, SARS-CoV-2 spike-IgG antibody levels, Nucleocapsid-protein-IgG-antibodies, and vaccine tolerability were assessed 6 weeks after second SARS-CoV-2 vaccination in 137 hemodialysis patients and 24 immunocompetent medical personnel. In COVID-19-naïve hemodialysis patients, significantly higher median SARS-CoV-2-spike IgG levels were found after ChAd/BNT (N = 16) compared to BNT/BNT (N = 100) or ChAd/ChAd (N = 10) (1744 [25th-75th percentile 276-2840] BAU/mL versus 361 [25th-75th percentile 120-936] BAU/mL; p = 0.009; 1744 [25th-75th percentile 276-2840] BAU/mL versus 100 [25th-75th percentile 41-346] BAU/mL; p = 0.017, respectively). Vaccinated, COVID-19-naïve medical personnel had median SARS-CoV-2 spike-IgG levels of 650 (25th-75th percentile 217-1402) BAU/mL and vaccinated hemodialysis patients with prior COVID-19 7047 (25th-75th percentile 685-10,794) BAU/mL (N = 11). In multivariable regression analysis, heterologous vaccination (ChAd/BNT) of COVID-19-naïve hemodialysis patients was independently associated with SARS-CoV-2 spike-IgG levels. The first dose of ChAd and the second dose of BNT after the first vaccination with ChAd (heterologous vaccination, ChAd/BNT) were associated with more frequent but manageable side effects compared with homologous BNT. Within the limitations of this study, heterologous vaccination with ChAd/BNT appears to induce stronger humoral immunity and more frequent but manageable side effects than homologous vaccination with BNT/BNT or with ChAd/ChAd in COVID-19-naïve hemodialysis patients.

Haase M ，Lesny P ，Anderson M ，Cloherty G ，Stec M ，Haase-Fielitz A ，Haarhaus M ，Santos-Araújo C ，Veiga PM ，Macario F ... -  《-》

Persistence of immune responses after heterologous and homologous third COVID-19 vaccine dose schedules in the UK: eight-month analyses of the COV-BOOST trial.

COV-BOOST is a multicentre, randomised, controlled, phase 2 trial of seven COVID-19 vaccines used as a third booster dose in June 2021. Monovalent messenger RNA (mRNA) COVID-19 vaccines were subsequently widely used for the third and fourth-dose vaccination campaigns in high-income countries. Real-world vaccine effectiveness against symptomatic infections following third doses declined during the Omicron wave. This report compares the immunogenicity and kinetics of responses to third doses of vaccines from day (D) 28 to D242 following third doses in seven study arms. The trial initially included ten experimental vaccine arms (seven full-dose, three half-dose) delivered at three groups of six sites. Participants in each site group were randomised to three or four experimental vaccines, or MenACWY control. The trial was stratified such that half of participants had previously received two primary doses of ChAdOx1 nCov-19 (Oxford-AstraZeneca; hereafter referred to as ChAd) and half had received two doses of BNT162b2 (Pfizer-BioNtech, hereafter referred to as BNT). The D242 follow-up was done in seven arms (five full-dose, two half-dose). The BNT vaccine was used as the reference as it was the most commonly deployed third-dose vaccine in clinical practice in high-income countries. The primary analysis was conducted using all randomised and baseline seronegative participants who were SARS-CoV-2 naïve during the study and who had not received a further COVID-19 vaccine for any reason since third dose randomisation. Among the 817 participants included in this report, the median age was 72 years (IQR: 55-78) with 50.7% being female. The decay rates of anti-spike IgG between vaccines are different among both populations who received initial doses of ChAd/ChAd and BNT/BNT. In the population that previously received ChAd/ChAd, mRNA vaccines had the highest titre at D242 following their vaccine dose although Ad26. COV2. S (Janssen; hereafter referred to as Ad26) showed slower decay. For people who received BNT/BNT as their initial doses, a slower decay was also seen in the Ad26 and ChAd arms. The anti-spike IgG became significantly higher in the Ad26 arm compared to the BNT arm as early as 3 months following vaccination. Similar decay rates were seen between BNT and half-BNT; the geometric mean ratios ranged from 0.76 to 0.94 at different time points. The difference in decay rates between vaccines was similar for wild-type live virus-neutralising antibodies and that seen for anti-spike IgG. For cellular responses, the persistence was similar between study arms. Heterologous third doses with viral vector vaccines following two doses of mRNA achieve more durable humoral responses compared with three doses of mRNA vaccines. Lower doses of mRNA vaccines could be considered for future booster campaigns.

Liu X ，Munro APS ，Wright A ，Feng S ，Janani L ，Aley PK ，Babbage G ，Baker J ，Baxter D ，Bawa T ，Bula M ，Cathie K ，Chatterjee K ，Dodd K ，Enever Y ，Fox L ，Qureshi E ，Goodman AL ，Green CA ，Haughney J ，Hicks A ，Jones CE ，Kanji N ，van der Klaauw AA ，Libri V ，Llewelyn MJ ，Mansfield R ，Maallah M ，McGregor AC ，Minassian AM ，Moore P ，Mughal M ，Mujadidi YF ，Belhadef HT ，Holliday K ，Osanlou O ，Osanlou R ，Owens DR ，Pacurar M ，Palfreeman A ，Pan D ，Rampling T ，Regan K ，Saich S ，Saralaya D ，Sharma S ，Sheridan R ，Stokes M ，Thomson EC ，Todd S ，Twelves C ，Read RC ，Charlton S ，Hallis B ，Ramsay M ，Andrews N ，Lambe T ，Nguyen-Van-Tam JS ，Cornelius V ，Snape MD ，Faust SN ，COV-BOOST study group ... -  《-》

Safety and immunogenicity of heterologous versus homologous prime-boost schedules with an adenoviral vectored and mRNA COVID-19 vaccine (Com-COV): a single-blind, randomised, non-inferiority trial.

Use of heterologous prime-boost COVID-19 vaccine schedules could facilitate mass COVID-19 immunisation. However, we have previously reported that heterologous schedules incorporating an adenoviral vectored vaccine (ChAdOx1 nCoV-19, AstraZeneca; hereafter referred to as ChAd) and an mRNA vaccine (BNT162b2, Pfizer-BioNTech; hereafter referred to as BNT) at a 4-week interval are more reactogenic than homologous schedules. Here, we report the safety and immunogenicity of heterologous schedules with the ChAd and BNT vaccines. Com-COV is a participant-blinded, randomised, non-inferiority trial evaluating vaccine safety, reactogenicity, and immunogenicity. Adults aged 50 years and older with no or well controlled comorbidities and no previous SARS-CoV-2 infection by laboratory confirmation were eligible and were recruited at eight sites across the UK. The majority of eligible participants were enrolled into the general cohort (28-day or 84-day prime-boost intervals), who were randomly assigned (1:1:1:1:1:1:1:1) to receive ChAd/ChAd, ChAd/BNT, BNT/BNT, or BNT/ChAd, administered at either 28-day or 84-day prime-boost intervals. A small subset of eligible participants (n=100) were enrolled into an immunology cohort, who had additional blood tests to evaluate immune responses; these participants were randomly assigned (1:1:1:1) to the four schedules (28-day interval only). Participants were masked to the vaccine received but not to the prime-boost interval. The primary endpoint was the geometric mean ratio (GMR) of serum SARS-CoV-2 anti-spike IgG concentration (measured by ELISA) at 28 days after boost, when comparing ChAd/BNT with ChAd/ChAd, and BNT/ChAd with BNT/BNT. The heterologous schedules were considered non-inferior to the approved homologous schedules if the lower limit of the one-sided 97·5% CI of the GMR of these comparisons was greater than 0·63. The primary analysis was done in the per-protocol population, who were seronegative at baseline. Safety analyses were done among participants receiving at least one dose of a study vaccine. The trial is registered with ISRCTN, 69254139. Between Feb 11 and Feb 26, 2021, 830 participants were enrolled and randomised, including 463 participants with a 28-day prime-boost interval, for whom results are reported here. The mean age of participants was 57·8 years (SD 4·7), with 212 (46%) female participants and 117 (25%) from ethnic minorities. At day 28 post boost, the geometric mean concentration of SARS-CoV-2 anti-spike IgG in ChAd/BNT recipients (12 906 ELU/mL) was non-inferior to that in ChAd/ChAd recipients (1392 ELU/mL), with a GMR of 9·2 (one-sided 97·5% CI 7·5 to ∞). In participants primed with BNT, we did not show non-inferiority of the heterologous schedule (BNT/ChAd, 7133 ELU/mL) against the homologous schedule (BNT/BNT, 14 080 ELU/mL), with a GMR of 0·51 (one-sided 97·5% CI 0·43 to ∞). Four serious adverse events occurred across all groups, none of which were considered to be related to immunisation. Despite the BNT/ChAd regimen not meeting non-inferiority criteria, the SARS-CoV-2 anti-spike IgG concentrations of both heterologous schedules were higher than that of a licensed vaccine schedule (ChAd/ChAd) with proven efficacy against COVID-19 disease and hospitalisation. Along with the higher immunogenicity of ChAd/BNT compared with ChAD/ChAd, these data support flexibility in the use of heterologous prime-boost vaccination using ChAd and BNT COVID-19 vaccines. UK Vaccine Task Force and National Institute for Health Research.

Liu X ，Shaw RH ，Stuart ASV ，Greenland M ，Aley PK ，Andrews NJ ，Cameron JC ，Charlton S ，Clutterbuck EA ，Collins AM ，Dinesh T ，England A ，Faust SN ，Ferreira DM ，Finn A ，Green CA ，Hallis B ，Heath PT ，Hill H ，Lambe T ，Lazarus R ，Libri V ，Long F ，Mujadidi YF ，Plested EL ，Provstgaard-Morys S ，Ramasamy MN ，Ramsay M ，Read RC ，Robinson H ，Singh N ，Turner DPJ ，Turner PJ ，Walker LL ，White R ，Nguyen-Van-Tam JS ，Snape MD ，Com-COV Study Group ... -  《-》

Persistence of immunogenicity after seven COVID-19 vaccines given as third dose boosters following two doses of ChAdOx1 nCov-19 or BNT162b2 in the UK: Three month analyses of the COV-BOOST trial.

To evaluate the persistence of immunogenicity three months after third dose boosters. COV-BOOST is a multicentre, randomised, controlled, phase 2 trial of seven COVID-19 vaccines used as a third booster dose. The analysis was conducted using all randomised participants who were SARS-CoV-2 naïve during the study. Amongst the 2883 participants randomised, there were 2422 SARS-CoV-2 naïve participants until D84 visit included in the analysis with median age of 70 (IQR: 30-94) years. In the participants who had two initial doses of ChAdOx1 nCov-19 (Oxford-AstraZeneca; hereafter referred to as ChAd), schedules using mRNA vaccines as third dose have the highest anti-spike IgG at D84 (e.g. geometric mean concentration of 8674 ELU/ml (95% CI: 7461-10,085) following ChAd/ChAd/BNT162b2 (Pfizer-BioNtech, hearafter referred to as BNT)). However, in people who had two initial doses of BNT there was no significant difference at D84 in people given ChAd versus BNT (geometric mean ratio (GMR) of 0.95 (95%CI: 0.78, 1.15). Also, people given Ad26.COV2.S (Janssen; hereafter referred to as Ad26) as a third dose had significantly higher anti-spike IgG at D84 than BNT (GMR of 1.20, 95%CI: 1.01,1.43). Responses at D84 between people who received BNT (15 μg) or BNT (30 μg) after ChAd/ChAd or BNT/BNT were similar, with anti-spike IgG GMRs of half-BNT (15 μg) versus BNT (30 μg) ranging between 0.74-0.86. The decay rate of cellular responses were similar between all the vaccine schedules and doses. 84 days after a third dose of COVID-19 vaccine the decay rates of humoral response were different between vaccines. Adenoviral vector vaccine anti-spike IgG concentrations at D84 following BNT/BNT initial doses were similar to or even higher than for a three dose (BNT/BNT/BNT) schedule. Half dose BNT immune responses were similar to full dose responses. While high antibody tires are desirable in situations of high transmission of new variants of concern, the maintenance of immune responses that confer long-lasting protection against severe disease or death is also of critical importance. Policymakers may also consider adenoviral vector, fractional dose of mRNA, or other non-mRNA vaccines as third doses.

Liu X ，Munro APS ，Feng S ，Janani L ，Aley PK ，Babbage G ，Baxter D ，Bula M ，Cathie K ，Chatterjee K ，Dejnirattisai W ，Dodd K ，Enever Y ，Qureshi E ，Goodman AL ，Green CA ，Harndahl L ，Haughney J ，Hicks A ，van der Klaauw AA ，Kwok J ，Libri V ，Llewelyn MJ ，McGregor AC ，Minassian AM ，Moore P ，Mughal M ，Mujadidi YF ，Holliday K ，Osanlou O ，Osanlou R ，Owens DR ，Pacurar M ，Palfreeman A ，Pan D ，Rampling T ，Regan K ，Saich S ，Serafimova T ，Saralaya D ，Screaton GR ，Sharma S ，Sheridan R ，Sturdy A ，Supasa P ，Thomson EC ，Todd S ，Twelves C ，Read RC ，Charlton S ，Hallis B ，Ramsay M ，Andrews N ，Lambe T ，Nguyen-Van-Tam JS ，Cornelius V ，Snape MD ，Faust SN ，COV-BOOST study group ... -  《-》

Immunogenicity, safety, and reactogenicity of heterologous COVID-19 primary vaccination incorporating mRNA, viral-vector, and protein-adjuvant vaccines in the UK (Com-COV2): a single-blind, randomised, phase 2, non-inferiority trial.

Given the importance of flexible use of different COVID-19 vaccines within the same schedule to facilitate rapid deployment, we studied mixed priming schedules incorporating an adenoviral-vectored vaccine (ChAdOx1 nCoV-19 [ChAd], AstraZeneca), two mRNA vaccines (BNT162b2 [BNT], Pfizer-BioNTech, and mRNA-1273 [m1273], Moderna) and a nanoparticle vaccine containing SARS-CoV-2 spike glycoprotein and Matrix-M adjuvant (NVX-CoV2373 [NVX], Novavax). Com-COV2 is a single-blind, randomised, non-inferiority trial in which adults aged 50 years and older, previously immunised with a single dose of ChAd or BNT in the community, were randomly assigned (in random blocks of three and six) within these cohorts in a 1:1:1 ratio to receive a second dose intramuscularly (8-12 weeks after the first dose) with the homologous vaccine, m1273, or NVX. The primary endpoint was the geometric mean ratio (GMR) of serum SARS-CoV-2 anti-spike IgG concentrations measured by ELISA in heterologous versus homologous schedules at 28 days after the second dose, with a non-inferiority criterion of the GMR above 0·63 for the one-sided 98·75% CI. The primary analysis was on the per-protocol population, who were seronegative at baseline. Safety analyses were done for all participants who received a dose of study vaccine. The trial is registered with ISRCTN, number 27841311. Between April 19 and May 14, 2021, 1072 participants were enrolled at a median of 9·4 weeks after receipt of a single dose of ChAd (n=540, 47% female) or BNT (n=532, 40% female). In ChAd-primed participants, geometric mean concentration (GMC) 28 days after a boost of SARS-CoV-2 anti-spike IgG in recipients of ChAd/m1273 (20 114 ELISA laboratory units [ELU]/mL [95% CI 18 160 to 22 279]) and ChAd/NVX (5597 ELU/mL [4756 to 6586]) was non-inferior to that of ChAd/ChAd recipients (1971 ELU/mL [1718 to 2262]) with a GMR of 10·2 (one-sided 98·75% CI 8·4 to ∞) for ChAd/m1273 and 2·8 (2·2 to ∞) for ChAd/NVX, compared with ChAd/ChAd. In BNT-primed participants, non-inferiority was shown for BNT/m1273 (GMC 22 978 ELU/mL [95% CI 20 597 to 25 636]) but not for BNT/NVX (8874 ELU/mL [7391 to 10 654]), compared with BNT/BNT (16 929 ELU/mL [15 025 to 19 075]) with a GMR of 1·3 (one-sided 98·75% CI 1·1 to ∞) for BNT/m1273 and 0·5 (0·4 to ∞) for BNT/NVX, compared with BNT/BNT; however, NVX still induced an 18-fold rise in GMC 28 days after vaccination. There were 15 serious adverse events, none considered related to immunisation. Heterologous second dosing with m1273, but not NVX, increased transient systemic reactogenicity compared with homologous schedules. Multiple vaccines are appropriate to complete primary immunisation following priming with BNT or ChAd, facilitating rapid vaccine deployment globally and supporting recognition of such schedules for vaccine certification. UK Vaccine Task Force, Coalition for Epidemic Preparedness Innovations (CEPI), and National Institute for Health Research. NVX vaccine was supplied for use in the trial by Novavax.

Stuart ASV ，Shaw RH ，Liu X ，Greenland M ，Aley PK ，Andrews NJ ，Cameron JC ，Charlton S ，Clutterbuck EA ，Collins AM ，Darton T ，Dinesh T ，Duncan CJA ，England A ，Faust SN ，Ferreira DM ，Finn A ，Goodman AL ，Green CA ，Hallis B ，Heath PT ，Hill H ，Horsington BM ，Lambe T ，Lazarus R ，Libri V ，Lillie PJ ，Mujadidi YF ，Payne R ，Plested EL ，Provstgaard-Morys S ，Ramasamy MN ，Ramsay M ，Read RC ，Robinson H ，Screaton GR ，Singh N ，Turner DPJ ，Turner PJ ，Vichos I ，White R ，Nguyen-Van-Tam JS ，Snape MD ，Com-COV2 Study Group ... -  《-》