The importance of influenza vaccination during the COVID-19 pandemic

Inhibition of influenza A virus and SARS-CoV-2 infection or co-infection by griffithsin and griffithsin-based bivalent entry inhibitor

Outbreaks of acute respiratory viral diseases, such as influenza and COVID-19 caused by influenza A virus (IAV) and SARS-CoV-2, pose a serious threat to global public health, economic security, and social stability. This calls for the development of broad-spectrum antivirals to prevent or treat infection or co-infection of IAV and SARS-CoV-2. Hemagglutinin (HA) on IAV and spike (S) protein on SARS-CoV-2, which contain various types of glycans, play crucial roles in mediating viral entry into host cells. Therefore, they are key targets for the development of carbohydrate-binding protein-based antivirals. This study demonstrated that griffithsin (GRFT) and the GRFT-based bivalent entry inhibitor GL25E (GRFT-L25-EK1) showed broad-spectrum antiviral effects against IAV infection in vitro by binding to HA in a carbohydrate-dependent manner and effectively protected mice from lethal IAV infection. Although both GRFT and GL25E could inhibit infection of SARS-CoV-2 Omicron variants, GL25E proved to be significantly more effective than GRFT and EK1 alone. Furthermore, GL25E effectively inhibited in vitro co-infection of IAV and SARS-CoV-2 and demonstrated good druggability, including favorable safety and stability profiles. These findings suggest that GL25E is a promising candidate for further development as a broad-spectrum antiviral drug for the prevention and treatment of infection or co-infection from IAV and SARS-CoV-2.IMPORTANCEInfluenza and COVID-19 are highly contagious respiratory illnesses caused by the influenza A virus (IAV) and SARS-CoV-2, respectively. IAV and SARS-CoV-2 co-infection exacerbates damage to lung tissue and leads to more severe clinical symptoms, thus calling for the development of broad-spectrum antivirals for combating IAV and SARS-CoV-2 infection or co-infection. Here we found that griffithsin (GRFT), a carbohydrate-binding protein, and GL25E, a recombinant protein consisting of GRFT, a 25 amino acid linker, and EK1, a broad-spectrum coronavirus inhibitor, could effectively inhibit IAV and SARS-CoV-2 infection and co-infection by targeting glycans on HA of IAV and spike (S) protein of SARS-CoV-2. GL25E is more effective than GRFT because GL25E can also interact with the HR1 domain in SARS-CoV-2 S protein. Furthermore, GL25E possesses favorable safety and stability profiles, suggesting that it is a promising candidate for development as a drug to prevent and treat IAV and SARS-CoV-2 infection or co-infection.

The association between influenza vaccination and the perception of COVID-19 as well as COVID-19 vaccination behavior among community residents in Anhui province, China

Influenza is a significant public health threat associated with high morbidity and mortality globally. This study investigated the influenza vaccination rate (IVR) among community residents in Anhui province, China, and explored the association between participants' influenza vaccination and their key sociodemographic characteristics, perception of COVID-19 as well as COVID-19 vaccination behavior. We found that the IVR among respondents in Anhui province was 27.85% in 2020. Regression analyses revealed that males (OR = 1.41, 95% CI: 1.01 ~ 1.96), residents with above middle school education (OR = 1.88, 95% CI: 1.04 ~ 3.39), considered themselves likely to be infected with COVID-19 (OR = 1.53, 95% CI: 1.04 ~ 2.24), had received the COVID-19 vaccine (OR = 9.85, 95% CI: 3.49 ~ 27.78), did not plan to receive COVID-19 vaccine in the future (OR = 1.70, 95% CI: 1.17 ~ 2.47), and had no adverse reactions after COVID-19 vaccination (OR = 1.54, 95% CI: 1.04 ~ 2.27) were associated with a higher IVR. The acceptance of influenza vaccination was mainly associated with respondents' gender, education, perception of COVID-19, history of COVID-19 vaccination in city and countryside community residents in Anhui province.

Impact of COVID-19 Pandemic on the Influenza Vaccination and Predictors of Influenza Vaccination in Japan: A Cross-sectional Study

OBJECTIVE

With the current global pandemic of COVID-19, there is concern that an influenza outbreak could exacerbate the health care burden. Improving the influenza vaccination rate is becoming more critical because controlling the spread of influenza is essential for reducing excess mortality. Therefore, we investigated whether the influenza vaccination rate changed during the COVID-19 pandemic in Japan and identified the factors associated with influenza vaccination uptake.

DESIGN

This cross-sectional study used data from an Internet survey with adjustments to approximate a nationally representative estimate using inverse probability weighting.

SETTING

A total of 23 142 respondents, aged 15 to 80 years, were evaluated to estimate weighted percentages and prevalence ratios with 95% confidence intervals of influenza vaccination in the period 2020-2021.

RESULTS

Overall, in the period 2020-2021, the influenza vaccination rate rose from 38.1% before the COVID-19 pandemic to 44.6%. "Using traditional media" was a positive predictor of influenza vaccination uptake. "Using social media," "COVID-19 vaccine hesitancy," and "living in a prefecture with a high proportion of COVID-19 cases" were negative predictors.

CONCLUSIONS

It is crucial to use predictors of influenza vaccination, such as how to use the media, for promoting a more widespread influenza vaccination uptake. The results of this study may be helpful in improving influenza vaccination rates, which could reduce the burden on health care services during outbreaks of influenza and COVID-19.

Antiviral Activity of Technologically Processed Antibodies to CD4 Receptor against Influenza Infection

The antiviral activity of technologically processed antibodies to CD4 receptor was evaluated a model of sublethal A/California/04/2009 (H1N1)pdm09-induced influenza infection in female BALB/c mice. The technologically processed antibodies increased animal survival rate by 50% in comparison with the placebo group (p<0.05), which correlated with significant inhibition of virus replication in the lungs (p<0.05). The reference drug Tamiflu increased mouse survival rate (by 47%), decreased the virus titer in the lungs, and prevented body weight loss (p<0.05 in comparison with the placebo group by all parameters). The intrinsic protective activity of technologically processed antibodies to CD4 receptor was demonstrated, which manifested in a decrease in viral load in the lower respiratory tract and an increase in the survival rate.

Correlation of clinical characteristics between patients with seasonal influenza and patients infected by the wild type or delta variant of SARS-CoV-2

Background

We compared the clinical characteristics of the patients with COVID-19, infected by the wild type or delta variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in connection with those of patients with seasonal influenza, all in mild cases.

Methods

We retrospectively studied 245 and 115 patients with mild COVID-19 infected by the wild type and the delta variant of SARS-CoV-2, respectively, with their demographic information, medical history, and laboratory data from hospital records, individually compared to 377 patients with mild seasonal influenza, before and after individual treatment.

Results

Compared to the influenza cohort, the COVID-19 cohort or the COVID-19 delta variant cohort demonstrated younger median age, lower male ratio, and shorter duration from disease onset to hospitalization. Hypertension remained the top comorbidity among all cohorts. Based on patients' data upon hospitalization, the correlation of clinical characteristics between patients with influenza and those with the wild-type COVID-19 is greater than that between patients with influenza and those with the delta variant COVID-19. Individual treatment in each viral disease alleviated most hematological parameters, but some compromised biomarkers at the time of hospital discharge revealed persistent renal or myocardial impairment among patients with COVID-19 and influenza in recovery.

Conclusion

Timely and proper treatment using broad-spectrum antibiotics and antiviral drugs could moderately alleviate the acute viremia and possible bacterial co-infection in patients with mild COVID-19 and influenza, followed by compromised recovery. To prepare for the flu season amid the COVID-19 pandemic, preventive and adequate immunizations of both flu and COVID-19 vaccines, as well as specific therapeutics to effectively reverse viral impairments, are in urgent need.

The double-edged impacts of COVID-19 epidemic on influenza vaccination uptake in nurses in Hong Kong

BACKGROUND

Worldwide, the COVID-19 pandemic has disrupted influenza seasonality and impacted influenza vaccination behaviours. This study examines the patterns of influenza vaccination uptake in nurses during the pre-pandemic seasons and amidst the pandemic in 2020/21 in subtropical Hong Kong.

METHODS

In April 2021, a cross-sectional survey was conducted in practising and student nurses. Six patterns were differentiated by their influenza vaccination status in 2020/21 and preceding five seasons: (a) resistance throughout, (b) negative change, (c) decreased tendency, (d) increased tendency (e) positive change, and (f) adherence throughout. Participants' characteristics and reasons for vaccination/non-vaccination and their associations with each vaccination pattern were explored using multivariable multinomial regression.

RESULTS

Among 1323 nurses (88% female with a median age of 39 years), no substantial change in vaccination uptake was noted from 2019/20 (41%) to 2020/21 (42%). Some 4% were positive-changers who were older at age of ≥50 years (aOR 4.77) and more likely to anticipate a reduced risk of severe disease with COVID-19/influenza co-infection following vaccination (aOR 8.76). Negative-changers made up 3% and were more inclined to perceive an unlikelihood of widespread influenza outbreaks amidst the pandemic (aOR 3.67). Some 26 and 43% remained adherent and resistant to influenza vaccination throughout respectively notwithstanding the COVID-19 outbreak.

CONCLUSIONS

In contrast to the increased uptake elsewhere, the stable influenza vaccination coverage among nurses in Hong Kong could be explained by the ubiquity of strict physical distancing regulations, which have deterred vaccination in some nurses that offsets the new uptakes induced by the mild COVID-19 outbreaks.

Safety and immunogenicity of a high-dose quadrivalent influenza vaccine administered concomitantly with a third dose of the mRNA-1273 SARS-CoV-2 vaccine in adults aged ≥65 years: a phase 2, randomised, open-label study

Background

Concomitant seasonal influenza vaccination with a COVID-19 vaccine booster could help to minimise potential disruption to the seasonal influenza vaccination campaign and maximise protection against both diseases among individuals at risk of severe disease and hospitalisation. This study aimed to assess the safety and immunogenicity of concomitant administration of high-dose quadrivalent influenza vaccine (QIV-HD) and a mRNA-1273 vaccine booster dose in older adults.

Methods

This study is an ongoing, phase 2, multicentre, open-label, descriptive trial at six clinical research sites in the USA. We describe the interim results up to 21 days after vaccination (July–August, 2021). Community-dwelling adults aged 65 years and older, who were previously vaccinated with a two-dose primary schedule of the mRNA-1273 SARS-CoV-2 vaccine, were eligible for inclusion. The second dose of the primary mRNA-1273 vaccination series was required to have been received at least 5 months before enrolment in the study. Participants were randomly assigned (1:1:1) using a permuted block method stratified by site and by age group (<75 years vs ≥75 years), to receive concomitant administration of QIV-HD and mRNA-1273 vaccine, QIV-HD alone, or mRNA-1273 vaccine alone. Randomisation lists, generated by Sanofi Pasteur biostatistics platform, were provided to study investigators for study group allocation. Unsolicited adverse events occurring immediately, solicited local and systemic reactions up to day 8, and unsolicited adverse events, serious adverse events, adverse events of special interest, and medically attended adverse events up to day 22 were reported. Haemagglutination inhibition antibody responses to influenza A/H1N1, A/H3N2, B/Yamagata, and B/Victoria strains and SARS CoV-2 binding antibody responses (SARS-CoV-2 pre-spike IgG ELISA) were assessed at day 1 and day 22. All analyses were descriptive. The study is registered with ClinicalTrials.gov, NCT04969276.

Findings

Between July 16 and Aug 31, 2021, 306 participants were enrolled and randomly assigned, of whom 296 received at least one vaccine dose (100 in the coadministration group, 92 in the QIV-HD, and 104 in the mRNA-1273 group). Reactogenicity profiles were similar between the coadministration and mRNA-1273 groups, with lower reactogenicity rates in the QIV-HD group (frequency of solicited injection site reactions 86·0% [95% CI 77·6–92·1], 91·3% [84·2–96·0], and 61·8% [50·9–71·9]; frequency of solicited systemic reactions 80·0%, [70·8–87·3], 83·7% [75·1–90·2], and 49·4% [38·7–60·2], respectively). Up to day 22, unsolicited adverse events were reported for 17·0% (95% CI 10·2–25·8) of participants in the coadministration group and 14·4% (8·3–22·7) of participants in the mRNA-1273 group, and tended to be reported at a slightly lower rate (10·9% [5·3–19·1]) in participants in the QIV-HD group. Seven participants each reported one medically attended adverse event (three in the coadministration group, one in the QIV-HD group, and three in the mRNA-1273 group). There were no serious adverse events, adverse events of special interest, or deaths. Haemagglutination inhibition antibody geometric mean titres increased from day 1 to day 22 to similar levels in the coadministration and QIV-HD groups, for each influenza strain (A/H1N1: 363 [95% CI 276–476] vs 366 [272–491]; A/H3N2: 286 [233–352] vs 315 [257–386]; B/Yamagata: 429 [350–525] vs 471 [378–588]; B/Victoria: 377 [325–438] vs 390 [327–465] for the coadministration and QIV-HD groups, respectively). SARS-CoV-2 binding antibody geometric mean concentrations also increased to similar levels in the coadministration and mRNA-1273 groups at day 22 (7634 [95% CI 6445–9042] and 7904 [6883–9077], respectively).

Interpretation

No safety concerns or immune interference were observed for concomitant administration of QIV-HD with mRNA-1273 booster in adults aged 65 years and older, supporting co-administration recommendations.

Funding

Sanofi Pasteur.

Acceptance of COVID-19 and Influenza Vaccine Co-Administration: Insights from a Representative Italian Survey

Co-administration of coronavirus disease 2019 (COVID-19) and seasonal influenza vaccines has several advantages, has been advocated by various public health authorities and should be seen as an opportunity to increase the uptake of both vaccines. The objective of this survey was to quantify the acceptance of concomitant COVID-19/influenza vaccination and to identify its correlates in a representative sample of Italian adults. Of 2463 participants, a total of 22.9% were favorable to vaccine co-administration, while 16.6% declared their firm unwillingness to receive both vaccines simultaneously. The remaining 60.5% of subjects could be dubbed hesitant to some degree. Compliance with the primary COVID-19 vaccination schedule (adjusted proportional odds ratio (aOR) = 7.78), previous influenza vaccination (aOR = 1.89) and trust in public health institutions (aOR = 1.22) were the main determinants of positive attitudes toward vaccine co-administration. Other significant correlates included age, sex, perceived disease severity and vaccination risk–benefit, being offered a more personalized influenza vaccine and recent seeking for influenza-related information. In Italy, hesitancy toward COVID-19/influenza vaccine co-administration is common and appears to be higher than hesitancy toward either vaccine administered alone. This pattern is multifaceted and requires specific and tailored strategies, with public health institutions playing the central role.