Breaking News
March 22, 2018 - New ocular inserts allow patient’s cornea to absorb more antibiotics
March 22, 2018 - FDA Alert: NeuroBlate Probe by Monteris Medical: Letter to Health Care Providers, Class I Recall
March 22, 2018 - Morning Break: Booze Study Brouhaha; Stem Cells for MS; Big Debt Problem
March 22, 2018 - New wearable tech from Western may hold big benefits for people with Parkinson’s
March 22, 2018 - Immune cells can repopulate in the retina after elimination, mice study shows
March 22, 2018 - Research provides better understanding of how cancerous cells behave in low oxygen
March 22, 2018 - Menopausal hormone therapy taken soon after menopause may benefit the brain
March 22, 2018 - Booze Boosts Your Heart Rate
March 22, 2018 - Skeptical Cardiologist: Classifying Heart Failure
March 22, 2018 - Instead of nagging your spouse to lose weight, try going on a diet yourself
March 22, 2018 - Neem Biotech to share findings on cystic fibrosis biofilm disruption at ECFS Basic Science Conference
March 22, 2018 - Study uncovers new genetic cause of posterior polymorphous corneal dystrophy
March 22, 2018 - ENDO: Big Breakfast May Help in Diabetics
March 22, 2018 - I’m not overweight, so why do I need to eat healthy foods?
March 22, 2018 - UCLA-led study suggests unexpected reason for reduction in cardiovascular health disparities
March 22, 2018 - Study suggests detailed neuropsychological assessment for brief cardiac arrest survivors
March 22, 2018 - Anticoagulant drugs found safe to use in patients undergoing surgery for irregular heartbeat
March 22, 2018 - SP Industries appoints Brian Larkin as new President and CEO
March 22, 2018 - GTx Announced New Data Demonstrating Enobosarm’s Potential to Treat Stress Urinary Incontinence
March 22, 2018 - Higher Risk of Brain Deficits in Older Alcoholics
March 22, 2018 - Top US health official resigns in conflict of interest
March 22, 2018 - Study shows benefits of hair loss drug in improving cognitive function and vascular health
March 22, 2018 - Researchers explain link between 2 key Alzheimer’s proteins
March 22, 2018 - Patients on replacement therapy with thyroid hormone may have more comorbidities
March 22, 2018 - Higher online patient ratings linked to urologists who saw fewer Medicare patients
March 22, 2018 - FDA Approves Ilumya (tildrakizumab-asmn) for the Treatment of Moderate-to-Severe Plaque Psoriasis
March 22, 2018 - Beer Raises Heart Rate; KardiaBand Hyperkalemia Test; CHD Clinics
March 22, 2018 - A retinal implant that is more effective against blindness
March 22, 2018 - New system based on artificial intelligence provides reliable detection of breast cancer
March 22, 2018 - Research offers new understanding about cause of Parkinson’s disease
March 22, 2018 - HORIBA’s Microsemi CRP analyzer improves quality of care in emergency pediatric units, study shows
March 22, 2018 - Neuroscientists move closer to developing tools for deciphering brain function
March 22, 2018 - New test methods with less fear
March 22, 2018 - Range of Vaginal Dryness Products Can Help Postmenopausal Women: Study
March 22, 2018 - Higher Dose Tx Deemed Safe in Pulmonary TB
March 22, 2018 - Discovery of new ALS gene points to cytoskeleton as potential target for drug development
March 22, 2018 - Diet soda associated with higher odds of diabetic retinopathy
March 22, 2018 - LSD reduces ‘sense of self’
March 22, 2018 - Vitamin D deficiency linked to metabolic syndrome in postmenopausal women
March 22, 2018 - Changes in the intestines may be responsible for reversal of diabetes after bariatric surgery
March 22, 2018 - iPads and Cancer; Clot Retrieval and Stroke: It’s PodMed Double T!
March 22, 2018 - Premature births linked to changes in mother’s bacteria
March 22, 2018 - Brain SPECT scans predict treatment outcomes in patients with depression
March 21, 2018 - Researchers succeed in integrating artificial organelles into cells of living organism
March 21, 2018 - Researchers discover ‘missing mutation’ in severe infant epilepsy
March 21, 2018 - Researchers develop statistics-based computational scheme to zoom in on brain function
March 21, 2018 - Verge joins Genomics England’s Discovery Forum industry partnership
March 21, 2018 - Trovagene Announces First Patient Successfully Completes Cycle 1 of Treatment with PCM-075 in Combination with Low Dose Cytarabine (LDAC) in AML Trial
March 21, 2018 - Congenital Cardiac Cath Tx Often Strays from Guidelines
March 21, 2018 - Marked increase in cardiovascular risk factors in women after preeclampsia
March 21, 2018 - New app may help predict, track manic and depressive episodes in bipolar patients
March 21, 2018 - Discovery of genes could lead to development of novel therapies for EBV-related cancers
March 21, 2018 - High-fat, high-cholesterol diet depletes ranks of artery-protecting immune cells
March 21, 2018 - Research misconduct allegations shadow likely CDC appointee
March 21, 2018 - Most Breast Ca Patients Fail to Get Genetic Counseling
March 21, 2018 - Lopsided ear function can lead to lopsided brain development
March 21, 2018 - Acupuncture helps manage menopausal symptoms, review finds
March 21, 2018 - Motor skill training may contribute to reading skills in obese children
March 21, 2018 - Poor dental health may be related to increased diabetes risk
March 21, 2018 - Chronic opioid users at increased risk of complications after spinal fusion surgery
March 21, 2018 - Study uncovers potential therapeutic target against large family of parasites
March 21, 2018 - NSAID use linked to increased risk of atrial fibrillation
March 21, 2018 - Scientists develop brain “stethoscope” that can detect silent seizures
March 21, 2018 - New method predicts effects of global warming on disease
March 21, 2018 - Insurance Company Hurdles Burden Doctors, May Harm Patients
March 21, 2018 - Renal Transplant from HCV-Positive Donors Feasible
March 21, 2018 - Myelodysplastic syndrome: MedlinePlus Medical Encyclopedia
March 21, 2018 - Research reveals brain mechanism involved in language learning
March 21, 2018 - Many parents still hesitate to try early peanut introduction, survey finds
March 21, 2018 - Audiologist urges tinnitus sufferers facing ‘revolving door healthcare’ to seek support
March 21, 2018 - Study reveals impact of prostate cancer on wives and partners of sufferers
March 21, 2018 - ‘Almost a Miracle Drug’: What We Heard This Week
March 21, 2018 - Study shows NIH spent >$100 billion on basic science for new medicines
March 21, 2018 - Columbia researchers identify nerve cells that drive fruit fly’s escape behavior
March 21, 2018 - Sartorius Stedim Biotech selected by ABL Europe to supply single-use process technologies
March 21, 2018 - Increase in coffee consumption may help battle against colon cancer
March 21, 2018 - Hydrogel may accelerate healing of diabetic ulcers
March 21, 2018 - Dermira’s Two Phase 3 Trials Evaluating Olumacostat Glasaretil in Patients with Acne Vulgaris Did Not Meet Co-Primary Endpoints
March 21, 2018 - DePuy Synthes introduces ACTIS Total Hip System for improving initial implant stability
March 21, 2018 - ‘Oh, It Was Nothing’
Altering genetic mutation could enhance FluMist vaccine’s protective effect

Altering genetic mutation could enhance FluMist vaccine’s protective effect

image_pdfDownload PDFimage_print

Researchers at Johns Hopkins Bloomberg School of Public Health have discovered a genetic mutation in the FluMist intranasal flu vaccine that has the potential to be altered to enhance the vaccine’s protective effect.

This flu season marks the second that the panel that advises the Centers for Disease Control and Prevention (CDC) on vaccines has recommended that FluMist not be used in the U.S. The Advisory Committee on Immunization Practice found that the vaccine had grown less effective in recent years, possibly due to shifts in circulating flu strains, and researchers have been searching for ways to restore its effectiveness.

In the new study, the Bloomberg School researchers discovered a previously overlooked mutation, present within two of the viral strains used in the vaccine, that reduces virus production. When the researchers reversed the mutation in one of the viruses, the virus became more active, making copies of itself – which is known as replicating – more quickly in cultured human nasal cells and inducing a stronger production of immune proteins.

The findings appears in the journal Vaccine.

“Only one component of FluMist – the one targeting the Type A H1N1 virus – has been failing in the U.S. recently,” says Andrew S. Pekosz, PhD, professor in the Bloomberg School’s Department of Molecular Microbiology and Immunology. “It’s not clear exactly why it has failed but this mutation we identified could be used to make that component of the vaccine a little stronger, thereby improving vaccine efficacy. We now see the possibility of altering this mutation and perhaps others in the vaccine to optimize the vaccine’s protective effect, perhaps for different age groups.”

Three types of influenza viruses affect people, Type A, Type B and Type C, and flu vaccines include a mix of virus strains tailored to anticipate the upcoming flu season. The CDC estimates that over the past seven years, flu viruses have caused 9.2 million to 60.8 million illnesses, 140,000 to 710,000 hospitalizations, and 12,000 to 56,000 deaths annually in the U.S. Across the globe, there are an estimated three to five million cases of severe flu cases and about 250,000 to 500,000 deaths.

The FluMist vaccine, also known as LAIV (live, attenuated influenza vaccine) is made from four weakened flu virus strains, two representing the influenza A type, and two representing the influenza B type. Two segments of the strains used in the vaccine are altered periodically to match the strains of influenza circulating in the population.

The non-varying parts of the vaccine are made from a special, cold-adapted H2N2 strain that is known to contain mutations that slow its replication at the temperatures found in the human nose and throat. That slowing of activity is largely what keeps these vaccine strains from causing illness in people, although they remain active enough to induce at least partial immune protection against future influenza A infections.

Scientists in previous studies have linked the slower replication of this cold-adapted strain to changes in three virus genes. However, there have been hints in recent years, from Pekosz’s work and others’, that another gene encoding a viral protein called M2 may also contribute to this effect.

“We had studied M2 for years, but one day recently a student in my lab noticed that the M2 in the LAIV influenza A viruses contains a mutation in the same part of the protein that we had previously identified as affecting viral replication,” Pekosz says.

The researchers found that when they introduced this same mutation into a strain of influenza A virus that normally doesn’t have it, the replication rate of the virus dropped. Alternate mutations at the same site on the M2 gene also resulted in a slowing of viral replication.

The team then did the opposite experiment, starting with a FluMist influenza A strain and reversing the M2 mutation. They found that this enhanced the replication rate of the strain in human nasal cells.

The enhanced activity of the virus also led to a jump in production, in infected cells, of the immune protein interferon lambda, indicating an increased immune response. The result showed in principle that this mutation site, and perhaps others on the virus, may be used as “dimmer switches” to adjust the vaccine’s strength up or down–so that it induces a robustly protective immune response without also causing illness.

“What we’re trying to do now is make a panel of these LAIV viruses with different mutations to see if we can boost the replication rates to get vaccine formulations that protect children and other age groups better than LAIV has done in the past few years,” Pekosz says.


Tagged with:

About author

Related Articles