ABSTRACT
BackgroundThe safety and immunogenicity profile of COVID-19 vaccines when administered concomitantly with seasonal influenza vaccines has not yet been reported. MethodsA sub-study on influenza vaccine co-administration was conducted as part of the phase 3 randomized trial of the safety and efficacy of NVX-CoV2373. The first [~]400 participants meeting main study entry criteria and with no contraindications to influenza vaccination were invited to join the sub-study. After randomization in a 1:1 ratio to receive NVX-CoV2373 (n=217) or placebo (n=214), sub-study participants received an age-appropriate, licensed, open-label influenza vaccine with dose 1 of NVX-CoV2373. Reactogenicity was evaluated via electronic diary for 7 days post-vaccination in addition to monitoring for unsolicited adverse events (AEs), medically-attended AEs (MAAEs), and serious AEs (SAEs). Influenza haemagglutination inhibition and SARS-CoV-2 anti-spike IgG assays were performed. Vaccine efficacy against PCR-confirmed, symptomatic COVID-19 was assessed. Comparisons were made between sub-study and main study participants. FindingsSub-study participants were younger, more racially diverse, and had fewer comorbid conditions than main study participants. Reactogenicity events more common in the co-administration group included tenderness (70.1% vs 57.6%) or pain (39.7% vs 29.3%) at injection site, fatigue (27.7% vs 19.4%), and muscle pain (28.3% vs 21.4%). Rates of unsolicited AEs, MAAEs, and SAEs were low and balanced between the two groups. Co-administration resulted in no change to influenza vaccine immune response, while a reduction in antibody responses to the NVX-CoV2373 vaccine was noted. Vaccine efficacy in the sub-study was 87.5% (95% CI: -0.2, 98.4) while efficacy in the main study was 89.8% (95% CI: 79.7, 95.5). InterpretationThis is the first study to demonstrate the safety, immunogenicity, and efficacy profile of a COVID-19 vaccine when co-administered with seasonal influenza vaccines. The results suggest concomitant vaccination may be a viable immunisation strategy. FundingThis study was funded by Novavax, Inc. Research in ContextO_ST_ABSEvidence before this studyC_ST_ABSWe searched PubMed for research articles published from December 2019 until 1 April 2021 with no language restrictions for the terms "SARS-CoV-2", "COVID-19", "vaccine", "co-administration", and "immunogenicity". There were no peer-reviewed publications describing the simultaneous use of any SARS-CoV-2 vaccine and another vaccine. Several vaccine manufacturers had recent publications on phase 3 trials results (Pfizer/BioNTech, Moderna, AstraZeneca, Janssen, and the Gamaleya Research Institute of Epidemiology and Microbiology). Neither these publications nor their clinical trials protocols (when publicly available) described co-administration and they often had trial criteria specifically excluding those with recent or planned vaccination with any licenced vaccine near or at the time of any study injection. Added value of this studyImmune interference and safety are always a concern when two vaccines are administered at the same time. This is the first study to demonstrate the safety and immunogenicity profile and clinical vaccine efficacy of a COVID-19 vaccine when co-administered with a seasonal influenza vaccine. Implications of all the available evidenceThis study provides much needed information to help guide national immunisation policy decision making on the critical issue of concomitant use of COVID-19 vaccines with influenza vaccines.
ABSTRACT
The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) continues to spread globally. As SARS-CoV-2 has transmitted from person to person, variant viruses have emerged with elevated transmission rates and higher risk of infection for vaccinees. We present data showing that a recombinant prefusion-stabilized Spike (rS) protein based on the B.1.351 sequence (rS-B.1.351) was highly immunogenic in mice and produced neutralizing antibodies against SARS-CoV-2/WA1, B.1.1.7, and B.1.351. Mice vaccinated with our prototype vaccine NVX-CoV2373 (rS-WU1) or rS-B.1.351 alone, in combination, or as a heterologous prime boost, were protected when challenged with live SARS-CoV-2/B.1.1.7 or SARS-CoV-2/B.1.351. Virus titer was reduced to undetectable levels in the lungs post-challenge in all vaccinated mice, and Th1-skewed cellular responses were observed. A strong anamnestic response was demonstrated in baboons boosted with rS-B.1.351 approximately one year after immunization with NVX-CoV2373 (rS-WU1). An rS-B.1.351 vaccine alone or in combination with prototype rS-WU1 induced protective antibody- and cell-mediated responses that were protective against challenge with SARS-CoV-2 variant viruses.
ABSTRACT
BackgroundCovid-19 vaccines are urgently needed, especially against emerging variants. NVX-CoV2373 is a recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 rS) nanoparticle vaccine containing trimeric full-length SARS-CoV-2 spike glycoprotein and Matrix-M adjuvant. MethodsA phase 3, randomized, observer-blinded, placebo-controlled trial was conducted in adults 18-84 years old who received two intramuscular 5-{micro}g doses, 21 days apart, of NVX-CoV2373 or placebo (1:1) across 33 sites in the United Kingdom. The primary efficacy endpoint was virologically confirmed symptomatic Covid-19 with onset 7 days after second vaccination in serologically negative participants. ResultsA total of 15,187 participants were randomized, of whom 7569 received NVX-CoV2373 and 7570 received placebo; 27.2% were 65 years or older, 44.7% had comorbidities and 4.2% had baseline serological evidence of SARS-CoV-2. There were 10 cases of Covid-19 among NVX-CoV2373 recipients and 96 cases among placebo recipients, with symptom onset at least 7 days after second vaccination; NVX-CoV2373 was 89.7% (95% confidence interval, 80.2 to 94.6) effective in preventing Covid-19, with no hospitalizations or deaths reported. There were five cases of severe Covid-19, all in the placebo group. Post hoc analysis revealed efficacies of 96.4% (73.8 to 99.5) and 86.3% (71.3 to 93.5) against the prototype strain and B.1.1.7 variant, respectively. Vaccine efficacy was similar across subgroups, including participants with comorbidities and those [≥]65 years old. Reactogenicity was generally mild and transient. The incidence of serious adverse events was low and similar in the two groups. ConclusionA two-dose regimen of NVX-CoV2373 conferred 89.7% protection against a blend of prototype and variant Covid-19, demonstrated high efficacy against the B.1.1.7 variant, and had a reassuring safety profile. (Funded by Novavax, Inc. EudraCT number, 2020-004123-16).
ABSTRACT
The 2019 outbreak of a severe respiratory disease caused by an emerging coronavirus, SARS-CoV-2, has spread globally with high morbidity and mortality. Co-circulating seasonal influenza has greatly diminished recently, but expected to return with novel strains emerging, thus requiring annual strain adjustments. We have developed a recombinant hemagglutinin (HA) quadrivalent nanoparticle influenza vaccine (qNIV) produced using an established recombinant insect cell expression system to produce nanoparticles. Influenza qNIV adjuvanted with Matrix-M was well-tolerated and induced robust antibody and cellular responses, notably against both homologous and drifted A/H3N2 viruses in Phase 1, 2, and 3 trials. We also developed a full-length SARS-CoV-2 spike protein vaccine which is stable in the prefusion conformation (NVX-CoV2373) using the same platform technology. In phase 3 clinical trials, NVX-CoV2373 is highly immunogenic and protective against the prototype strain and B.1.1.7 variant. Here we describe the immunogenicity and efficacy of a combination quadrivalent seasonal flu and COVID-19 vaccine (qNIV/CoV2373) in ferret and hamster models. The combination qNIV/CoV2373 vaccine produces high titer influenza hemagglutination inhibiting (HAI) and neutralizing antibodies against influenza A and B strains. The combination vaccine also elicited antibodies that block SARS-CoV-2 spike protein binding to the human angiotensin converting enzyme-2 (hACE2) receptor. Significantly, hamsters immunized with qNIV/CoV2373 vaccine and challenged with SARS-CoV-2 were protected against weight loss and were free of replicating SARS-CoV-2 in the upper and lower respiratory tract with no evidence of viral pneumonia. This study supports evaluation of qNIV/CoV2373 combination vaccine as a preventive measure for seasonal influenza and CoVID-19. HighlightsO_LICombination qNIV/CoV2373 vaccine induced protective hemagglutination inhibition (HAI) responses to seasonal influenza A and B unchanged when formulated with recombinant spike. C_LIO_LICombination qNIV/CoV2373 vaccine maintained clinical and virologic protection against experimental challenge with SARS-CoV-2. C_LIO_LICombination qNIV/CoV2373 vaccine showed no clinical or histological sign of enhanced disease following experimental challenge with SARS-CoV-2. C_LIO_LICombination qNIV/CoV2373 vaccine induced antibodies against SARS-CoV-2 neutralizing epitopes common between US-WA and B.1.352 variant. C_LI
ABSTRACT
Vaccine efforts against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for the current COVID-19 pandemic are focused on SARS-CoV-2 spike glycoprotein, the primary target for neutralizing antibodies. Here, we performed cryo-EM and site-specific glycan analysis of one of the leading subunit vaccine candidates from Novavax based on a full-length spike protein formulated in polysorbate 80 (PS 80) detergent. Our studies reveal a stable prefusion conformation of the spike immunogen with slight differences in the S1 subunit compared to published spike ectodomain structures. Interestingly, we also observed novel interactions between the spike trimers allowing formation of higher order spike complexes. This study confirms the structural integrity of the full-length spike protein immunogen and provides a basis for interpreting immune responses to this multivalent nanoparticle immunogen.
