Immunogenicity and safety of concomitant administration of recombinant COVID-19 vaccine and quadrivalent inactivated influenza vaccine in Chinese adults: An open-label, randomized, controlled trial

The immunogenicity and safety of the concomitant administration of recombinant COVID-19 vaccine and quadrivalent inactivated influenza vaccine (Split Virion) (QIIV) in Chinese adults are unclear. In this open-label, randomized controlled trial, participants aged ≥ 18 years were recruited. Eligible healthy adults were randomly assigned (1:1) to receive QIIV at the same time as the first dose of COVID-19 vaccine (simultaneous-group) or 14 days after the second dose of COVID-19 vaccine (non-simultaneous-group). The primary outcome was to compare the difference in immunogenicity of QIIV (H1N1, H3N2, Yamagata, and Victoria) between the two groups. A total of 299 participants were enrolled, 149 in the simultaneous-group and 150 in the non-simultaneous-group. There were no significant differences in geometric mean titer (GMT) [H1N1: 386.4 (95%CI: 299.2-499.0) vs. 497.4 (95%CI: 377.5-655.3); H3N2: 66.9 (95%CI: 56.1-79.8) vs. 81.4 (95%CI: 67.9-97.5); Yamagata: 95.6 (95%CI: 79.0-115.8) vs. 74.3 (95%CI: 58.6-94.0); and Victoria: 48.5 (95%CI: 37.6-62.6) vs. 65.8 (95%CI: 49.0-88.4)] and seroconversion rate (H1N1: 87.5% vs. 90.1%; H3N2: 58.1% vs. 62.0%; Yamagata: 75.0% vs. 64.5%; and Victoria: 55.1% vs. 62.8%) of QIIV antibodies between the simultaneous and non-simultaneous groups. For the seroprotection rate of QIIV antibodies, a higher seroprotection rate of Yamagata antibody was observed only in the simultaneous-group than in the non-simultaneous-group [86.0% vs. 76.0%, p = .040]. In addition, no significant difference in adverse events was observed between the two groups (14.2% vs. 23.5%, p = .053). In conclusion, no immune interference or safety concerns were found for concomitant administration of COVID-19 vaccine with QIIV in adults aged ≥ 18 years.

Relative Effectiveness of the MF59®-Adjuvanted Influenza Vaccine Versus High-Dose and Non-Adjuvanted Influenza Vaccines in Preventing Cardiorespiratory Hospitalizations During the 2019-2020 US Influenza Season

BACKGROUND

Adults ≥ 65 years of age have suboptimal influenza vaccination responses compared to younger adults due to age-related immunosenescence. Two vaccines were specifically developed to enhance protection: MF59-adjuvanted trivalent influenza vaccine (aIIV3) and high-dose egg-based trivalent influenza vaccine (HD-IIV3e).

METHODS

In a retrospective cohort study conducted using US electronic medical records linked to claims data during the 2019-2020 influenza season, we compared the relative vaccine effectiveness (rVE) of aIIV3 with HD-IIV3e and a standard-dose non-adjuvanted egg-based quadrivalent inactivated influenza vaccine (IIV4e) for the prevention of cardiorespiratory hospitalizations, including influenza hospitalizations. We evaluated outcomes in the "any" diagnosis position and the "admitting" position on the claim. A doubly robust methodology using inverse probability of treatment weighting and logistic regression was used to adjust for covariate imbalance. rVE was calculated as 100 * (1 - ORadjusted).

RESULTS

The study included 4,299,594 adults ≥ 65 years of age who received aIIV3, HD-IIV3e, or IIV4e. Overall, aIIV3 was associated with lower proportions of cardiorespiratory hospitalizations with diagnoses in any position compared to HD-IIV3e (rVE = 3.9% [95% CI, 2.7-5.0]) or IIV4e (9.0% [95% CI, 7.7-10.4]). Specifically, aIIV3 was more effective compared with HD-IIV3e and IIV4e in preventing influenza hospitalizations (HD-IIV3e: 9.7% [95% CI, 1.9-17.0]; IIV4e: 25.3% [95% CI, 17.7-32.2]). Consistent trends were observed for admitting diagnoses.

CONCLUSION

Relative to both HD-IIV3e and IIV4e, aIIV3 provided improved protection from cardiorespiratory or influenza hospitalizations.

Relative Effectiveness of Cell-based Versus Egg-based Quadrivalent Influenza Vaccines in Children and Adolescents in the United States During the 2019-2020 Influenza Season

BACKGROUND

Egg-based influenza vaccine production can lead to the accumulation of mutations that affect antigenicity. The mammalian cell-based inactivated quadrivalent influenza vaccine (IIV4c) may improve effectiveness compared with egg-based vaccines. This study estimated the relative vaccine effectiveness (rVE) of IIV4c versus egg-based inactivated quadrivalent influenza vaccine (IIV4e) in preventing influenza-related medical encounters (IRME) among children and adolescents during the 2019-2020 US influenza season.

METHODS

This retrospective cohort study used a dataset linking primary and specialty care electronic medical records with medical and pharmacy claims data from US residents 4 through 17 years of age vaccinated with IIV4c or IIV4e during the 2019-2020 influenza season. Odds ratios (ORs) were derived from a doubly robust inverse probability of treatment-weighted approach adjusting for age, sex, race, ethnicity, region, index week, health status and two proxy variables for healthcare accessibility and use. Adjusted rVE was estimated by (1-OR adjusted )*100, and an exploratory analysis evaluated IRMEs separately for outpatient and inpatient settings.

RESULTS

The final study cohort included 60,480 (IIV4c) and 1,240,990 (IIV4e) vaccine recipients. Fewer IRMEs were reported in subjects vaccinated with IIV4c than IIV4e. The rVE for IIV4c versus IIV4e was 12.2% [95% confidence interval (CI): 7.5-16.6] for any IRME and 14.3% (9.3-19.0) for outpatient IRMEs. Inpatient IRMEs were much less frequent, and effectiveness estimates were around the null.

CONCLUSIONS

Fewer IRMEs occurred in pediatric subjects vaccinated with IIV4c versus IIV4e. These results support the greater effectiveness of IIV4c over IIV4e in this population during the 2019-2020 US influenza season.

Relative Effectiveness of the Cell-derived Inactivated Quadrivalent Influenza Vaccine Versus Egg-derived Inactivated Quadrivalent Influenza Vaccines in Preventing Influenza-related Medical Encounters During the 2018-2019 Influenza Season in the United States

Background

The cell-propagated inactivated quadrivalent influenza vaccine (ccIIV4) may offer improved protection in seasons where egg-derived influenza viruses undergo mutations that affect antigenicity. This study estimated the relative vaccine effectiveness (rVE) of ccIIV4 versus egg-derived inactivated quadrivalent influenza vaccine (eIIV4) in preventing influenza-related medical encounters in the 2018–2019 US season.

Methods

A dataset linking primary care electronic medical records with medical claims data was used to conduct a retrospective cohort study among individuals ≥ 4 years old vaccinated with ccIIV4 or eIIV4 during the 2018–2019 season. Adjusted odds ratios (ORs) were derived from a doubly robust inverse probability of treatment-weighted approach adjusting for age, sex, race, ethnicity, geographic region, vaccination week, and health status. rVE was estimated by (1 – OR) × 100 and presented with 95% confidence intervals (CI).

Results

Following the application of inclusion/exclusion criteria, the study cohort included 2 125 430 ccIIV4 and 8 000 903 eIIV4 recipients. Adjusted analyses demonstrated a greater reduction in influenza-related medical encounters with ccIIV4 versus eIIV4, with the following rVE: overall, 7.6% (95% CI, 6.5–8.6); age 4–17 years, 3.9% (95% CI, .9–7.0); 18–64 years, 6.5% (95% CI, 5.2–7.9); 18–49 years, 7.5% (95% CI, 5.7–9.3); 50–64 years, 5.6% (95% CI, 3.6–7.6); and ≥65 years, –2.2% (95% CI, –5.4 to .9).

Conclusions

Adjusted analyses demonstrated statistically significantly greater reduction in influenza-related medical encounters in individuals vaccinated with ccIIV4 versus eIIV4 in the 2018–2019 US influenza season. These results support ccIIV4 as a potentially more effective public health measure against influenza than an egg-based equivalent.

Coadministration of 13-valent pneumococcal conjugate and quadrivalent inactivated influenza vaccines in adults previously immunized with polysaccharide pneumococcal vaccine 23: a randomized clinical trial

Immune responses to 13-valent pneumococcal conjugate vaccine (PCV13) and quadrivalent inactivated influenza vaccine (QIV) in older adults may vary with coadministration and previous pneumococcal polysaccharide vaccination. This study assessed safety and noninferiority of immune responses to coadministered PCV13 and QIV compared with each vaccine given alone. Adults ≥50 years old preimmunized with ≥1 dose of 23-valent pneumococcal polysaccharide vaccine (PPSV23) ≥1 year before enrollment were randomized 1:1 to receive PCV13+QIV then placebo 1 month later or placebo+QIV then PCV13 1 month later. Administration of PCV13 and placebo was blinded; QIV was administered open-label. Pneumococcal serotype-specific opsonophagocytic activity (OPA) geometric mean titers (GMTs) 1 month after PCV13, and influenza hemagglutination inhibition assay GMTs 1 month after QIV were measured. Prespecified noninferiority was demonstrated by a lower bound of the 2-sided 95% CI for geometric mean ratios >0.5. Safety endpoints included proportions of subjects with adverse and serious adverse events. Of 882 randomized subjects, 846 comprised the evaluable immunogenicity population. Immune responses to all 13 pneumococcal serotypes and all 4 influenza strains 1 month after PCV13+QIV were noninferior to responses 1 month after each vaccine given alone. No safety concerns were identified. Immune responses to coadministered PCV13 and QIV were noninferior to responses after each vaccine given alone, although generally lower for coadministered PCV13. PCV13 and QIV can be administered concomitantly to adults ≥50 years of age preimmunized with PPSV23.

Immunogenicity and safety of the 2015 Southern Hemisphere formulation of a split-virion inactivated quadrivalent vaccine

An inactivated split-virion quadrivalent influenza vaccine (IIV4; Fluzone® Quadrivalent; Sanofi Pasteur) has been available in the US since 2013 and in the Southern Hemisphere since 2015. Here, we describe the results of an open-label, post-licensure trial (WHO Universal Trial Number, U1111-1143-9256) to confirm the immunogenicity and safety of the Southern Hemisphere 2015 formulation of IIV4. Adults 18–60 years of age and > 60 years of age (n = 60 per age group) received a single 0.5-mL intramuscular injection of IIV4. After vaccination, hemagglutination inhibition titers for each strain in IIV4 increased by a geometric mean of at least 10-fold for younger adults and at least 9-fold for older adults. All of the younger adult participants and 98%–100% of the older adult participants had seroprotective titers for each strain. Also, at least 80% of younger adults and 78% of older adults seroconverted or had a significant increase in titer for all four vaccine strains. These post-vaccination immune responses exceeded the criteria of the Committee for Human Medicinal Products former Note for Guidance for influenza vaccines. Finally, no serious adverse events were reported, and no new safety signals were detected. These results confirmed that the Southern Hemisphere 2015 formulation of IIV4 was well tolerated, highly immunogenic, and met the criteria for influenza vaccine immunogenicity and safety.

Safety and immunogenicity of an intramuscular quadrivalent influenza vaccine in children 3 to 8 y of age: A phase III randomized controlled study

A quadrivalent, inactivated, split-virion influenza vaccine containing a strain from both B lineages (IIV4) has been developed, but its safety and immunogenicity in young children has not been described. This was a phase III, randomized, double-blind, active-controlled, multi-center study to examine the immunogenicity and safety of IIV4 in children 3–8 y of age (EudraCT no. 2011-005374-33). Participants were randomized 5:1:1 to receive the 2013/2014 Northern Hemisphere formulation of IIV4, an investigational trivalent comparator (IIV3) containing the B/Victoria lineage strain, or the licensed Northern Hemisphere IIV3 containing the B/Yamagata lineage strain. Participants who had not previously received a full influenza vaccination schedule received 2 doses of vaccine 28 d apart; all others received a single dose. 1242 children were included. For all 4 strains, IIV4 induced geometric mean haemagglutination inhibition titres non-inferior to those induced by the IIV3 comparators. For both B strains, geometric mean antibody titres induced by IIV4 were superior to those induced by the IIV3 with the alternative lineage strain. Similar proportions of participants vaccinated with IIV4 and IIV3 reported solicited injection-site reactions, solicited systemic reactions, and vaccine-related adverse events. A single vaccine-related serious adverse event, thrombocytopenia, was reported 9 d after vaccination with IIV4 and resolved without sequelae. In conclusion, in children aged 3–8 y who received one dose or 2 doses 28 d apart, IIV4 had an acceptable safety profile, was as immunogenic as IIV3 for the shared strains, and had superior immunogenicity for the additional B strain.