Vaccine Info

Influenza Vaccines

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Last reviewed
September 18, 2021

Flu Shots for 2021-2022 - What's New

Influenza vaccines, known as flu shots, protect people against the influenza viruses that research indicates will be most common during the upcoming flu season. Influenza viruses belong to the Orthomyxoviridae RNA virus family and classify into three distinct types based on their significant antigenic differences; influenza A, influenza B, and influenza C, reports the U.S. NIH.

Most importantly, influenza vaccines do not cause the seasonal flu since they are made with either killed or weakened viruses, says the U.S. CDC.

The U.S. FDA’s Vaccines and Related Biological Products Advisory Committee published recommendations for the 2021-2022 flu season on this webpage. Influenza vaccines are manufactured differently, and different preparations have different indications as licensed by the U.S. FDA. The types of influenza vaccine include inactivated influenza vaccines (IIV) and live attenuated influenza vaccines (LAIV). In addition, two new influenza vaccines have been licensed for use in people aged 65 and older; a quadrivalent high-dose influenza vaccine and a quadrivalent adjuvanted influenza vaccine. The European Medicines Agency also announced its flu shot recommendations for the Fall of 2021.

On June 24, 2021, the CDC's vaccine committee reviewed Influenza Vaccines Expected to be Available by Age Indication, United States, 2021–22 Influenza Season, which included 'Influenza Vaccine Contraindications and Precautions—Allergic Reactions to Influenza Vaccines or their Components.' The ACIP affirmed the updated MMWR Recommendations and Reports.

Flu Shot Availability for 2021-2022

On September 15, 2021, the U.S. FDA confirmed the number of flu vaccine lots released and available for distribution in the USA. Over 190 million flu vaccines are expected to be distributed the 2021-2022 flu season.

COVID-19 Vaccines and Flu Shots

The CDC's ACIP stated 'If coadministered, COVID-19 vaccines and vaccines that might be more likely to cause a local reaction (e.g., aIIV4 or HD-IIV4) should be administered in different limbs, if possible.' However, 'No data are currently available concerning coadministration of currently Authorized COVID-19 vaccines and influenza vaccines,' stated Lisa Grohskopf, M.D., MPH, ACIP vaccine committee presentation (slide #14) on June 24, 2021.

Quadrivalent Influenza Vaccines: 2021-2022 Flu Season

Six months and older:

Afluria is an inactivated quadrivalent influenza vaccine indicated for active immunization against influenza disease caused by subtypes A and B.

Fluarix is prepared from influenza viruses propagated in embryonated chicken eggs.

Flulaval is a quadrivalent, split-virion, inactivated influenza virus vaccine prepared from virus propagated in the allantoic cavity of embryonated hens’ eggs.

Fluzone Quadrivalent is an inactivated vaccine that prevents influenza disease caused by influenza A subtype viruses and type B viruses.

Two-49 years of age:

FluMist is an Intranasal vaccine that is a live quadrivalent vaccine formulated to contain four vaccine virus strains.

Flucelvax is a cell culture-based flu vaccine to help offer protection against 4 flu virus strains. 

Eighteen-64 years of age:

Flublok is made without the use of eggs. Therefore, it is not subject to the mutations that are sometimes introduced into the vaccine during egg adaptation that can cause the traditional vaccines to be ineffective.

Sixty-five years and older:

Fluad consists of an inactivated, quadrivalent influenza virus antigen produced in eggs and an oil-in-water emulsion adjuvant, MF59C.1.

Fluzone High-Dose contains 4 times the antigen of standard-dose inactivated influenza vaccines.

Trivalent Influenza Vaccine: 2021-2022 Flu Season

Sixty-five years and older:

Fluad consists of an inactivated, trivalent influenza virus antigen produced in eggs and an oil-in-water emulsion adjuvant, MF59C.1.

Influenza Vaccine Candidates

Existing flu vaccines contain weakened or inactivated influenza viruses with a mix of hemagglutinins (HAs), the proteins that stud their surfaces. These vaccines primarily aim to trigger antibody responses against HA’s top part or head. Genetic changes in flu viruses rarely alter most of the head. But a small amount of the head reassorts, or mutates, frequently, allowing new viral strains to dodge any immune memory and forcing flu vaccine makers to prepare new formulations each year, with updated HAs, wrote Jon Cohen, a staff writer for Science.

Flu-v Influenza Vaccine is a synthetic universal flu vaccine candidate that offers protection across a broad influenza spectrum forcing 1+NP forcing vaccine candidate consisting of MVA, a replication-deficient pox viral vector safely tested in thousands of patients generate a strong immune reaction against Matrix 1 Nucleoprotein influenza antigens. 

NasoVAX is a recombinant intranasal vaccine that is being developed for both seasonal and pandemic use.

Redeeflu (M2SR) is a nasal vaccine candidate utilizing a proprietary M2 deleted, single replication influenza virus.

NanoFlu is a quadrivalent recombinant hemagglutinin (HA) protein nanoparticle influenza vaccine produced by Novavax in its SF9 insect cell baculovirus system. NanoFlu uses HA amino acid protein sequences similar to the recommended wild-type circulating virus HA sequences. In addition, NanoFlu contains Novavax's patented saponin-based Matrix-M™ adjuvant.

Zoonotic Influenza News 2021

Please visit the latest Avian and Swine Influenza News.

Influenza Vaccine News 2021

September 13, 2021 - The WHO published Influenza Update N° 402, which disclosed the WHO GISRS laboratories tested more than 282,929 specimens during the period and found less than 1% (1,580) were positive for influenza viruses, of which 983 (62.2%) were typed as influenza A and 597 (37.8%) as influenza B. 

September 12, 2021 - Local media reported India's National Centre for Disease Control confirmed from January to July 2021, only 65 H1N1 cases and no deaths were reported in the country. However, on July 21, 2021, India's National IHR focal point notified the WHO of one human case of avian influenza A(H5N1) from Haryana state, northern India. This is the first reported human infection of the influenza A(H5N1) virus in India.

September 10, 2021 - The U.S. CDC's Weekly U.S. Influenza Surveillance Report indicates influenza virus circulation remains very low; therefore, increases in Influenza-like Illness activity are likely due to the circulation of other respiratory viruses. Based on mortality surveillance data available on September 9, 2021, 20.1% of the deaths that occurred during the week ending September 4, 2021 (week 35) were due to pneumonia, influenza, and/or COVID-19 (PIC). Among the 3,388 PIC deaths reported for this week, 2,785 had COVID-19 listed as an underlying or contributing cause of death on the death certificate, and three listed influenza, indicating that current PIC mortality is primarily due to COVID-19 and pneumonia, but not influenza. 

September 9, 2021 - Public Health England reported the overall influenza positivity remained very low at 0.0% in week #35, with none of the 2,107 samples testing positive for influenza.

September 8, 2021 - Novavax, Inc. announced enrollment of participants in a Phase 1/2 study to evaluate the safety and immunogenicity of a combination vaccine using Novavax's NanoFlu seasonal influenza and COVID-19 vaccines. In preclinical studies, the COVID-NanoFlu Combination Vaccine demonstrated robust, functional immune responses to each component of the quadrivalent influenza vaccine and the SARS-CoV-2 spike protein, with Matrix-M adjuvant playing a key role.

September 7, 2021 - The American Academy of Pediatrics issued a Policy Statement: Recommendations for Prevention and Control of Influenza in Children, 2021–2022.

September 3, 2021 - The U.S. CDC's weekly flu report (#34) confirmed 'one influenza-associated pediatric death has occurred during the 2020-2021 season.'

September 2, 2021 - Public Health England reported In week #34, the overall influenza positivity in 2021 remained very low at 0.04%, with 1 of the 2,350 samples testing positive for influenza (influenza A(not subtyped)).

August 30, 2021 - In the WHO's N #401 Global Influenza update covering the first half of August 2021, influenza levels were reported to be very low in both hemispheres. The WHO GISRS laboratories tested more than 215,281 specimens during that time period: 1,424 were positive for influenza viruses, of which 927 (65%) were typed as influenza A and 497 (35%%) as influenza B. Of the sub-typed influenza A viruses, 55 (6.2%) were influenza A(H1N1)pdm09, and 830 (93.8%) were influenza A(H3N2). Of the 455 characterized B viruses, 100% belonged to the B-Victoria lineage.

August 27, 2021 - The U.S. CDC published its weekly report, which stated, 'Nationwide during week #33, 2.2% of patient visits reported through ILINet were due to ILI. Although increasing, the percentage of patient visits for ILI remains below the baseline of 2.6% nationally. Since influenza virus circulation remains low; therefore, increases in ILI activity are likely due to increased circulation of other respiratory viruses.

August 26, 2021 - the UK's PHE's Respiratory Datamart confirmed no influenza-positive samples were detected in week #33. In addition, other indicators for influenza such as hospital admissions and GP Influenza-like-Illness consultation rates remain very low.

August 24, 2021 - The JAMA Network published the findings of a cross-sectional study that identified racial and ethnic disparities in rates of influenza-associated hospitalization, ICU admission, and in-hospital death from the 2009 to 2010 through 2018 to 2019 influenza seasons, with the widest disparities occurring among young children from racial/ethnic minority groups. Because data were not available for the underlying source population, this analysis did not adjust rates for other factors, such as vaccination status, underlying medical conditions, receipt of antivirals, or illness severity at hospital admission, all of which could potentially impact findings.

August 23, 2021 - The U.S. CDC reported during week #32, 2.1% of patient visits reported through ILINet were due to ILI. Although increasing, the percentage of patient visits for ILI remains below the baseline of 2.6% nationally. One region (Region 4) is above their region-specific baseline, while the remaining regions are below their baselines. Influenza virus circulation remains low; therefore, increases in ILI activity are likely due to increased circulation of other respiratory viruses.

August 20, 2021 - The US Centers for Disease Control and Prevention confirmed (1) influenza-associated pediatric death occurring during the 2020-2021 season. This data compares with last flu season when (198) children died from influenza-related illness in the USA.

August 19, 2021 - Public Health England published Week #33 report (up to week 32 data). A total of 2,690 participants completed the weekly surveillance survey in week 31, of which 63 (2.3%) reported fever or cough and 24 (0.9%) reported influenza-like illness (ILI). The most commonly used healthcare service reported by respondents remains to telephone a GP practice.

August 16, 2021 - The WHO published Influenza Update N° 400 based on August 1, 2021. Globally, despite continued or even increased testing for influenza in some countries, influenza activity remained at lower levels than expected for this time of the year. 

August 13, 2021 - The U.S. CDC published the 2020-2021 Influenza Season for Week #31 report. Nationwide during week #31, 2.0% of patient visits reported were due to Influenza-like Illness (ILI). Although increasing, the percentage of patient visits for ILI remains below the national baseline of 2.6%.

August 9, 2021 - BioNTech SE confirmed BNT161, a Phase 1 clinical trial, is expected to start in the third quarter of 2021. The clinical trial will evaluate modified RNA influenza vaccine candidates based on the proven BNT162b2 COVID-19 vaccine platform. BNT161 is partnered with Pfizer Inc.

August 5, 2021 - A new study: Impact of mandatory vaccination of healthcare personnel on rates of influenza and other viral respiratory pathogens. 'Our fitted regression models suggest that if influenza vaccination rates in clinics where vaccination was not mandated had equaled those where the flu vaccine was mandated, HCP influenza infections would have been reduced by 52.1% (95% CI, 51.3%–53.0%). '

August 3, 2021 - The journal PLOS published a news study: Examining the potential benefits of the influenza vaccine against SARS-CoV-2: A retrospective cohort analysis of 74,754 patients. Conclusion - Significant findings favoring influenza vaccination mitigating the risks of sepsis, stroke, deep vein thrombosis, emergency department & Intensive Care Unit admissions suggest a potential protective effect that could benefit populations without readily available access to SARS-CoV-2 vaccination. 

August 2, 2021 - The WHO published Influenza Update N° 399 based on data from July 18, 2021. Globally, influenza activity remained at lower levels than expected for this time of the year. 

July 30, 2021 - The U.S. CDC reported for week #29. among the 1,381 PIC deaths confirmed last week, only one listed influenza.

July 29, 2021 - A new study: Single Replication M2SR Influenza Vaccine-Induced Immune Responses Associated with Protection Against Human Challenge with Highly Drifted H3N2 Influenza Strain. Conclusions: Subjects with vaccine-induced neutralizing antibodies were protected against infection and illness following a challenge with an antigenically distinct virus. This is the first demonstration of vaccine-induced protection against a highly drifted H3N2 challenge virus.

July 29, 2021 - PHE's Weekly national Influenza and COVID-19 surveillance report through Respiratory Datamart, one influenza-positive sample was detected in week #29 and influenza B. However, other indicators for influenza such as hospital admissions and GP influenza-like illness consultation rates remain low.

July 27, 2021 - Seqirus announced that it has begun to ship its portfolio of seasonal influenza vaccines across the U.S. in preparation for the 2021-2022 flu season. The company is supplying approximately 60 million doses of influenza vaccines for healthcare providers across the U.S.

July 23, 2021 - The U.S. CDC published: Changes in Influenza and Other Respiratory Virus Activity During the COVID-19 Pandemic — the United States, 2020–2021. Influenza viruses and human metapneumovirus circulated at historic lows through May 2021. In April 2021, respiratory syncytial virus activity increased. Common human coronaviruses, parainfluenza viruses, and respiratory adenoviruses have been increasing since January or February 2021. Rhinoviruses and enteroviruses began to increase in June 2020.

July 19, 2021 - The World Health Organization reported in its latest global flu update. Globally, despite continued or even increased testing for influenza in some countries, influenza activity remained at lower levels than expected for this time of the year. 

July 15, 2021 - The UK's NHS published 'National influenza and COVID-19 report, monitoring seasonal flu, and other seasonal respiratory illnesses.' Through Respiratory Datamart, there were no influenza-positive samples detected in week #27. Other indicators for influenza such as hospital admissions and GP influenzalike illness consultation rates remained low.

July 11, 2021 - According to a study presented at the European Congress of Clinical Microbiology & Infectious Diseases, using the real-time data of thousands of patients, allowing for precise cohort matching and increasing external validity. Our analysis outlines the potential protective effect of influenza vaccination in SARS-CoV-2-positive patients against 15 adverse outcomes within 30, 60, 90, and 120 days of a positive diagnosis. In addition, significant findings in favor of influenza vaccination in mitigating the risks of sepsis, stroke, DVT, ED & ICU admissions suggest a potential protective effect that could benefit populations without readily available access to SARS-CoV-2 vaccination and thus merits further investigation with future prospective studies.

July 9, 2021 - The U.S. CDC published Week #26 Influenza Surveillance report. No influenza-associated pediatric deaths were reported to CDC during week #26.

July 7, 2021 - Cambridge, MA-based Moderna, Inc. announced the first participants had been dosed in the Phase 1/2 study of mRNA-1010, a quadrivalent seasonal influenza mRNA vaccine candidate.

July 5, 2021 - The WHO reported 'Globally, despite continued or even increased testing for influenza in some countries, influenza activity remained at lower levels than expected for this time of the year. The WHO Global Influenza Surveillance and Response System laboratories tested more than 146,816 specimens and found only 766 specimens positive for influenza viruses, 682 (89%) as influenza B. All 624 (100%) were ascribed to the B-Victoria lineage of the type B viruses for which lineage was determined.

July 2, 2021 - The U.S. CDC reported 'nationwide during week #25, 1.2% of patient visits reported through ILINet were due to Influenza-like Illness. This percentage is below the national baseline of 2.6%. Additionally, one influenza-associated pediatric death occurring during the 2020-2021 season has been reported to CDC.

July 1, 2021 - FluGen, Inc. announced that it had been awarded funding from the United States DOD to conduct a study of M2SR, the Company's investigational, supra-seasonal, live, single-replication, intranasal influenza vaccine. 

June 30, 2021 - California-based Meissa Vaccines announced today the first seronegative participants had received MV-012-968, Meissa’s intranasal live attenuated RSV vaccine candidate, in a Phase 1c study in infants and young children.

June 25, 2021 - Public Health England published influenza surveillance results from the winter period, 2020-2021. Vaccine uptake in England varied by cohort for the 2020 to 2021 season. Vaccine uptake in the 65 years and over cohort and the 2 and 3-year-old cohorts is the highest ever achieved. Vaccine uptake in the 65 years and over cohort was 80.9%, compared to 72.4% in 2019 to 2020, and uptake in the 2 and 3-year-old cohorts was 56.7% compared to 43.8% in 2019 to 2020. Vaccine uptake in the clinically at-risk cohorts is higher than ever recorded, at 53.0%, compared to 44.9% in 2019 to 2020. Vaccine uptake in pregnant women in England in the 2020 to 2021 season remained stable at 43.6%, compared to 43.7% in 2019 to 2020.

June 22, 2021 - Sanofi Pasteur and Translate Bio (NASDAQ: TBIO), a clinical-stage messenger RNA (mRNA) therapeutics company, have initiated a Phase 1 clinical trial evaluating an mRNA-based investigational vaccine against seasonal influenza.

June 15, 2021 - The Journal of Experimental Medicine published a study led by Yale researchers that found common respiratory viruses jump-start the activity of interferon-stimulated genes, early-response molecules in the immune system, which can stop the SARS-CoV-2 virus replication within a person’s airway tissues infected with the common cold.

June 14, 2021 - The PAHO reported influenza B detections that accounted for most of the meager numbers of worldwide influenza detections.

June 14, 2021 - Seqirus US and Novavax Inc. announced the first study to demonstrate the safety, immunogenicity, and efficacy profile of a COVID-19 vaccine candidate when co-administered with seasonal influenza vaccines. The data non-peer-reviewed is now available on medRxiv.

June 8, 2021 - The JAMA published a population-based cohort study with a mean follow-up duration of 3.6 years; maternal influenza vaccination during pregnancy was not significantly associated with an increased risk of adverse early childhood health outcomes.

June 4, 2021 - Nationwide, during week #21, the U.S. CDC reported 1.1% of patient visits reported through ILINet were due to Influenza-like Illness. This percentage is below the national baseline of 2.6%.

June 3, 2021 - Data from a systematic review and meta-analysis published in Influenza and Other Respiratory Viruses confirming the benefit of Seqirus’ MF59®-adjuvanted trivalent seasonal influenza vaccine for adults 65 and older.

June 1, 2021 - The first doses of Seqirus’s enhanced influenza vaccine, destined for the U.K., come off a new high-speed fill-and-finish line in Liverpool, UK. Seqirus Liverpool is the largest vaccine manufacturing facility in the U.K., producing over 50m doses of seasonal influenza vaccine each year, with the ability to increase production to 200m doses in the event of an influenza pandemic.

May 28, 2021 - The U.S. CDC confirmed it performs genetic and antigenic characterization of U.S. viruses submitted from state and local health laboratories. These data compare how similar the currently circulating influenza viruses are to the reference viruses used for developing new influenza vaccines and monitor evolutionary changes that continually occur in circulating influenza viruses. The CDC reported it antigenically characterized 9 influenza viruses collected in the United States from September 27, 2020, to May 22, 2021.

May 24, 2021 - Study published by the journal Nature related to key factors impacting vaccine effectiveness among individuals. Results identify leptin (an adipose cell-secreted hormone) as a potential biomarker for vaccine efficacy, with low leptin levels associated with reduced vaccine responses in younger and older individuals.

May 3, 2021 - Seqirus-US announced Phase 3 clinical data demonstrating that the company's cell-based quadrivalent seasonal influenza vaccine (QIVc) was as safe and immunogenic as a standard quadrivalent seasonal influenza vaccine (QIV) in children six months through <4 years of age during the U.S. 2019/20 influenza season.

April 29, 2021 - Peer-reviewed research: Efficacy of live attenuated and inactivated influenza vaccines among children in rural India: A 2-year, randomized, triple-blind, placebo-controlled trial. In this study, LAIV and IIV vaccines were safe and moderately efficacious against influenza virus infection among Indian children.

April 20, 2021 - Seqirus, part of CSL Limited (ASX: CSL), announced new real-world evidence on the company's MF59® adjuvanted, trivalent influenza vaccine (aTIV) peer-reviewed medical journal Clinical Infectious Diseases. Study results indicate aTIV was more effective in reducing influenza-related medical encounters than standard egg-based quadrivalent influenza vaccine and high-dose trivalent influenza vaccine among adults 65 and older during the 2017/18 and 2018/19 U.S. influenza seasons.

April 15, 2021 - Longeveron Inc. (NASDAQ: LGVN) announced today the completion of the Company’s Phase I/II clinical study of using Lomecel-B to improve immune response to influenza vaccine in subjects with Aging Frailty. Lomecel-B is an allogeneic, bone marrow-derived medicinal signaling cell (MSC) product manufactured under current good manufacturing practices (cGMP) by Longeveron. It is anticipated that the top-line trial results will be announced in the 3rd quarter of 2021. Lomecel-B can reduce inflammation associated with Aging Frailty and promote an anti-inflammatory state by releasing anti-inflammatory molecules, which can balance the immune system and improve the function of B lymphocytes. In addition, as B cells are responsible for antibody production in response to vaccines, Lomecel-B may boost antibody generation and immunity following vaccination in subjects with Aging Frailty.

March 30, 2021 - The European Medicines Agency issued recommendations for the influenza virus strains that vaccine manufacturers should include in vaccines to prevent seasonal influenza from autumn 2021.

March 27, 2021 - A study conducted in France published in The Lancet concluded 'Among patients admitted to hospital with community-acquired pneumonia who met clinical stability criteria, discontinuing β-lactam treatment after 3 days was non-inferior to 8 days of treatment. These findings could allow a substantial reduction of antibiotic consumption.'

March 24, 2021 - Researchers at the University of Washington School of Medicine announced they had developed experimental flu shots that protect animals from a wide variety of seasonal and pandemic influenza strains. If proven safe and effective, these next-generation influenza vaccines may replace current seasonal options by protecting against many more strains that current vaccines do not adequately cover. A study appears in the March 24 edition of the journal Nature.

March 19, 2021 - The Australian Technical Advisory Group on Immunisation released advice for immunization providers in its Statement on administering seasonal influenza vaccines in 2021. This year both flu and COVID-19 vaccines will be available in Australia. Therefore, it is important to plan vaccination timing to give the best protection against both of these potentially serious diseases.

March 18, 2021 -  A paper published in the Journal of General Internal Medicine, physician-researchers at Beth Israel Deaconess Medical Center assessed the relative impact of COVID-19 on patients hospitalized with the viral infection in March and April 2020 versus patients hospitalized with influenza during the last five flu seasons at the medical center. Overall, the team demonstrated that COVID-19 cases resulted in significantly more weekly hospitalizations, more use of mechanical ventilation, and higher mortality rates than influenza.

March 8, 2021 - Certain patients have an increased risk of influenza infections and poor serologic response to standard influenza vaccination. A new study found that tandem high-dose influenza vaccination leads to more robust and durable seroprotection in high-risk patients.

March 4, 2021 - Seqirus announced that the U.S. Food and Drug Administration had approved FLUCELVAX® QUADRIVALENT, the company’s cell-based quadrivalent influenza vaccine, for an expanded age indication for people two years of age and older.

March 3, 2021 - RESEARCH ARTICLE INFLUENZA: Broad neutralization of H1 and H3 viruses by adjuvanted influenza HA stem vaccines in nonhuman primates. Antibodies elicited by these headless HA stabilized-stem vaccines neutralized diverse H1 and H3 influenza viruses. In addition, they shared a mode of recognition analogous to human bnAbs, suggesting that these vaccines have the potential to confer broadly protective immunity against diverse viruses responsible for seasonal and pandemic influenza infections in humans.

March 1, 2021 - PLOS reported 'the global burden of influenza-associated lower respiratory tract infections and hospitalizations among adults: A systematic review and meta-analysis. This meta-analysis estimated influenza viruses are associated with over 5 million hospitalizations worldwide per year. Together, the available data demonstrate the importance of influenza viruses as a cause of severe disease and hospitalizations in younger and older adults worldwide.'

February 26, 2021 - The WHO recommended influenza virus vaccine composition in the 2021 - 2022 northern hemisphere influenza season.

February 26, 2021 - The National IHR Focal Point for the Russian Federation recently notified the WHO of avian influenza A(H5N8) in seven human clinical specimens. These are the first reported detection of avian influenza A(H5N8) in humans. Furthermore, according to the latest notifications from the World Organization for Animal Health, Afghanistan became the latest country to report highly pathogenic H5N8 avian influenza in poultry.

February 24, 2021 - Russian authorities reported the detection of influenza A(H5N8) virus infection in seven poultry workers in an outbreak of highly pathogenic avian influenza (HPAI) A(H5N8) virus on a poultry farm in the south of Russia. All seven human cases were reported to be mild or asymptomatic. HPAI A(H5N8) viruses have circulated in European bird populations since 2014, causing large outbreaks and affecting several million birds and poultry.

February 22, 2021 - MAJOR ARTICLE: Impact of the Influenza Vaccine on COVID-19 Infection Rates and Severity. The odds of testing positive for COVID-19 were reduced in patients who received an influenza vaccine than those who did not by 24%.

February 17, 2021 - Twice annually, the WHO organizes consultations with an advisory group of experts to analyze influenza virus surveillance data generated by the WHO Global Influenza Surveillance and Response System (GISRS) and issues recommendations on the composition of influenza vaccines for the following influenza season. These recommendations are used by the national vaccine regulatory agencies and the pharmaceutical companies to develop, produce and license influenza vaccines.

February 9, 2021 - Study published by The Lancet: Prevention of influenza during mismatched seasons in older adults with an MF59-adjuvanted quadrivalent influenza vaccine: a randomized, controlled, multicentre, phase 3 efficacy study. Summary: The prespecified criterion for showing the efficacy of aQIV in older adults was not met during the influenza seasons with high amounts of vaccine strain mismatch. Vaccine efficacy was higher against influenza cases associated with higher fever, representing a more clinically significant disease.

February 9, 2021 - The findings of a systematic review and meta-analysis published by The JAMA Network suggest that given the similarity in immunogenicity between the reduced dose intradermal and full dose intramuscular influenza vaccine, the low-dose intradermal vaccine could be a reasonable alternative to standard-dose intramuscular vaccination. It will be important to determine if this dose-sparing finding holds across age groups and newer vaccines, particularly when recent high-dose formulations have demonstrated improved immunogenicity in older adults in whom immune responses have historically struggled.

February 8, 2021 - GAVI article: How COVID-19 is altering cold and flu seasons. Pandemic restrictions and wider use of flu vaccines may have explained 2020’s record low seasonal flu cases, but what will the picture look like in tropical countries with year-round flu?

February 3, 2021 - BioCryst Pharmaceuticals, Inc. announced that the U.S. Food and Drug Administration had approved a supplemental new drug application for RAPIVAB® (peramivir injection), expanding the patient population of RAPIVAB for the treatment of acute uncomplicated influenza to include patients six months and older who have been symptomatic for no more than two days. Before this FDA approval, RAPIVAB had been indicated for patients two years and older.

February 2, 2021 - Study: A replication-competent adenovirus-vectored influenza vaccine induces durable systemic and mucosal immunity. Intranasal influenza vaccine spurred strong immune response in the Phase 1 study and reported the U.S. NIH.

January 23, 2021 - Study: Clinical and Economic Outcomes Associated with Cell-Based Quadrivalent Influenza Vaccine vs. Standard-Dose Egg-Based Quadrivalent Influenza Vaccines during the 2018–19 Influenza Season in the United States. Among the overall cohort, QIVc had higher adjusted rVEs against hospitalizations/ER visits related to influenza, all-cause hospitalizations, and hospitalizations/ER visits associated with any respiratory event than QIVe-SD. The adjusted annualized all-cause total costs were higher for QIVe-SD compared to QIVc ((+$461); p < 0.05).

January 19, 2021 - Researchers observed decreased effectiveness of influenza vaccine with increasing time since vaccination for prevention of influenza A(H3N2), influenza A(H1N1)pdm09, and influenza B (Yamagata)-associated hospitalizations among adults. The maximum vaccine effectiveness (VE) was observed shortly after vaccination, followed by an absolute decline in VE of about 8 to 9% per month post-vaccination.

January 15, 2021 - The Massachusetts Department of Public Health is removing the vaccination requirement which applied to all children over the age of 6 months attending Massachusetts child care, pre-school, kindergarten, K-12, or college due to the “mild” flu season and the fledgling efforts to administer the COVID-19 vaccine.

January 14, 2021 - JAMA Network Original Investigation - Safety, Reactogenicity, and Health-Related Quality of Life After Trivalent Adjuvanted vs. Trivalent High-Dose Inactivated Influenza Vaccines in Older Adults. In a randomized clinical trial of 757 older adults (378 receiving aIIV3 and 379 receiving HD-IIV3), the proportion of participants with moderate-to-severe injection-site pain was not higher after aIIV3 than HD-IIV3. In addition, no vaccine-related serious adverse events occurred, and postvaccination health-related quality of life was similar between aIIV3 and IIV3-HD groups. These findings suggest that a safety standpoint, aIIV3 or HD-IIV3, is an acceptable option to prevent influenza in older adults.

January 12, 2021 - Over 80% of those aged 65 and over in England have received the flu vaccine so far this year, the highest uptake ever achieved, reported the NHS. This includes an uptake rate of 51.5% in clinical at-risk groups (under 65 years), the highest achieved in the last seven seasons. In addition, flu vaccine uptake rates are higher than last season for all other eligible groups.

January 12, 2021 - JAMA Network article: Broad, Durable Antibody Response in Universal Flu Vaccine Trial.

January 9, 2021 - A study published in the International Journal of Infectious Diseases found that early administration of Oseltamivir (Tamiflu) is associated with a reduction in 30-day readmissions and composite-outcome of 30-day readmissions and mortality adult hospitalized influenza patients when compared to delayed/no-treatment.

Universal Influenza Vaccine Research

A key focus of influenza research programs is developing a universal flu vaccine that provides robust, long-lasting protection against multiple flu subtypes, rather than a select few. Such a vaccine would eliminate the need to update and administer the seasonal flu vaccine each year. In addition, it could protect against newly emerging flu strains, potentially including those that could cause a flu pandemic.

Influenza Medicines

Several medications, such as Tamiflu or Xofluza (Baloxavir Marboxil), can reduce the seasonal flu's severity and duration. Still, they're most effective in the first 48 hours after experiencing influenza symptoms. In addition, access to these medicines requires a healthcare provider's prescription.

A JAMA Original Investigation published on August 13, 2021: Comparison of Antiviral Agents for Seasonal Influenza Outcomes in Healthy Adults and Children concluded 'all 4 antiviral agents assessed were associated with shortening TTAS; zanamivir was associated with the shortest time to alleviation of influenza symptoms, and baloxavir was associated with a reduced rate of influenza-related complications.'

    Influenza FAQs

    Note: This page's content is aggregated from the US CDC, the WHO, pharmaceutical manufacturers, university studies, and the Precision Vaccinations news network. This content is reviewed by healthcare professionals, such as Dr. Robert Carlson.

    Clinical Trials

    No clinical trials found