Tag Archives: immunity
Researchers from Cleveland Clinic’s Global Center for Pathogen Research & Human Health have developed a promising new COVID-19 vaccine candidate that utilizes nanotechnology and has shown strong efficacy in preclinical disease models.
According to new findings published in mBio, the vaccine produced potent neutralizing antibodies among preclinical models and also prevented infection and disease symptoms in the face of exposure to SARS-CoV-2 (the virus that causes COVID-19). An additional reason for the vaccine candidate’s early appeal is that it may be thermostable, which would make it easier to transport and store than currently authorized COVID-19 vaccines.
“Our vaccine candidate delivers antigens to trigger an immune response via nanoparticles engineered from ferritin–a protein found in almost all living organisms,” said Jae Jung, PhD, director of the Global Center for Human Health & Pathogen Research and co-senior author on the study. “This protein is an attractive biomaterial for vaccine and drug delivery for many reasons, including that it does not require strict temperature control.”
Added Dokyun (Leo) Kim, a graduate student in Dr. Jung’s lab and co-first author on the study, “This would dramatically ease shipping and storage constraints, which are challenges we’re currently experiencing in national distribution efforts. It would also be beneficial for distribution to developing countries.”
Other benefits of the protein nanoparticles include minimizing cellular damage and providing stronger immunity at lower doses than traditional protein subunit vaccines against other viruses, like influenza.
The team’s vaccine uses the ferritin nanoparticles to deliver tiny, weakened fragments from the region of the SARS-CoV-2 spike protein that selectively binds to the human entry point for the virus (this fragment is called the receptor-binding domain, or RBD). When the SARS-CoV-2 RBD binds with the human protein called ACE2 (angiotensin-converting enzyme 2), the virus can enter host cells and begin to replicate.
The researchers tested their vaccine candidate on a ferret model of COVID-19, which reflects the human immune response and disease development better than other preclinical models. Dr. Jung, a foremost authority in virology and virus-induced cancers, previously developed the world’s first COVID-19 ferret model–a discovery that has significantly advanced research into SARS-CoV-2 infection and transmission.
The DxTerity COVID-19 Saliva at-Home Collection Kit detects the presence of the virus but does not confirm immunity or detect antibodies. DxTerity‘s molecular-based PCR test received approval from the Food and Drug Administration last month. The test differs from the quicker and less expensive antigen tests, which use a nasal swab or throat swab to detect the virus.
A single COVID-19 testing kit is listed for $110, and a 10-pack bundle is available for $1,000.
Test takers must spit into a tube provided by the kit. The saliva sample is then inserted into a plastic bag and packed back into the box for shipment to one of DxTerity‘s laboratories certified by the Clinical Laboratory Improvement Amendments. Customers are also granted prepaid express return shipping with the test and should expect to receive results within 24 to 72 hours of sample receipt at the laboratory. DxTerity’s test is currently the only COVID-19 testing kit on Amazon.
“We have demonstrated the reliability and quality of our COVID-19 testing solution with big business and now we want to expand access to customers at home and small businesses,” said Bob Terbrueggen, founder and CEO of DxTerity, when he first announced the collaboration with the company last month. “Amazon is the perfect partner for expanding access to millions of U.S. customers.”
The test may not be valid for all travel purposes because sample collection is unsupervised, according to the product description. The Centers for Disease Control and Prevention recommends saliva specimens should be collected under supervision.
Amazon joins other retail giants in offering at-home COVID-19 saliva tests. Costco offers both regular and those approved for travel requirements to Hawaii, Bermuda and some other destinations for $129.99 and $139.99, respectively. However, the test has several dozen one-star reviews, with most complaining about delayed shipping and poor customer service from provider AZOVA.
For epidemiologists, the COVID-19 pandemic has greatly intensified their long-standing nightmare about another virus: the emergence of a new and deadly strain of flu. A universal flu vaccine, effective against any strain of the influenza virus that can infect humans, could protect us from this peril, but progress has been slow. A novel concept for one universal vaccine candidate has now passed its first test in a small clinical trial, its developers report today in Nature Medicine.
Seasonal flu vaccines induce antibodies against the “head” (slate) of the influenza surface protein hemagglutinin, but a new universal vaccine triggers antibodies (fragments of them shown in gray) that bind to the stalk (light blue) portion
“This is an important paper,” says Aubree Gordon, an epidemiologist at the University of Michigan School of Public Health who studies influenza transmission and vaccines.
The influenza virus rapidly accumulates mutations and easily “reassorts,” or swaps, genes between strains, creating variants that can dodge any past immunity people had acquired naturally or from vaccines. That’s why a new flu vaccine must be developed each year. 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 part of the head does reassort, or mutate, frequently, which allows new viral strains to dodge any immune memory and forces flu vaccinemakers to prepare new formulations each year, with updated HAs.
In the trial, 51 participants received the various vaccines and their antibodies were compared with those of 15 people who received placebos. A single shot of vaccine with chimeric HA inactivated viruses, the researchers report, “induced remarkably high antistalk antibody titers.”
Novavax announced Tuesday that its potential vaccine to prevent Covid-19 generated a promising immune response in an early stage clinical trial, but the biotech company’s stock fell briefly on concerns about its safety.
The phase one trial included 131 healthy participants between the ages 18 and 59 at two sites in Australia. Novavax said 106 participants received one of four dose levels of the potential vaccine, named NVX-CoV2373, with or without an adjuvant, which is an ingredient designed to enhance the immune response. The remaining 25 patients received a placebo. Participants received two doses of the potential vaccine via intramuscular injection approximately 21 days apart, the company reported. The vaccine produced neutralizing antibodies, which researchers believe are necessary to build immunity to the virus, and killer T-cells, the company said. Additionally, the neutralizing antibodies that were produced were higher than those seen in people who have recovered from Covid-19, Novavax underscored. The immune response was also stronger for those who had the adjuvant, the company said.
Novavax explained that the vaccine was well tolerated with no serious adverse events reported. Most patients reported tenderness and pain at the injection after the first dose, with some patients also reporting headaches, fatigue or muscle aches. Only one participant in the trial experienced a mild fever after a second dose, the company noted. Earlier media reports and analysts cited eight possible hospitalizations related to the study, but the company said no patients were hospitalized.
Abbott Laboratories’ antibody test for the new coronavirus is highly likely to correctly determine whether people have ever been infected with the fast-spreading virus, the company said, citing a U.S. study.
Researchers at the University of Washington School of Medicine report in the Journal of Clinical Microbiology that Abbott‘s test had a specificity of 99.9% and a sensitivity of 100%, suggesting very few false positives and no false negatives.
Antibody tests can tell whether a person has ever been infected and are considered crucial in efforts to get Americans back to work safely as the presence of antibodies to the virus indicates possible immunity to future infection.
Abbott’s test was launched last month under the U.S. Food and Drug Administration’s relaxed rules for some coronavirus tests, allowing their distribution before regulatory clearance. It has since received emergency use authorization from the FDA.
Abbott has already shipped more than 10 million antibody tests to hospitals and labs.