![]() The gene sequence was carefully designed to create a nanoparticle with a ferritin core that is studded with spike proteins. These cells then produce large quantities of the spike-ferritin nanoparticle. This combined gene is placed in an artificial piece of DNA called a plasmid that is inserted into cultured cells. This vaccine candidate also uses the genetic information for the original Wuhan strain’s spike protein, but it combines it with the genetic information for the ferritin nanoparticle. On April 20, 2022, a press release from the maker of NVX-CoV2373 announced that the combination vaccine was “well tolerated” and that the company will move forward with phase 2 clinical trials. The vaccine is also in clinical trials as an influenza/COVID-19 combination vaccine. Later, studies on NVX-CoV2373 showed the vaccine creates an immune response that can recognize both the delta and omicron variants. These trials happened before the delta or omicron variants were circulating, so vaccine efficacy against the newer variants could not be tested. The results, also published by The New England Journal of Medicine in December 2021, found that two shots given to adults 21 days apart showed about 90% efficacy in preventing infection seven days after the second shot. as alpha, beta, gamma, epsilon and iota variants of COVID-19 were circulating. It was also was tested in Mexico and the U.S. The results of that phase 3 clinical trial were published by The New England Journal of Medicine in September 2021. ![]() This vaccine was tested in the United Kingdom as alpha, gamma and beta variants of COVID-19 were spreading. The technical name for this is a recombinant protein nanoparticle.Īlthough similar to the messenger RNA lipid nanoparticle, there are two important differences: the NVX-CoV2373 nanoparticle contains the spike protein and not the messenger RNA for the spike protein, and it has a different saponin adjuvant. ![]() As they are on the virus, the spike proteins are on the outside, with the part that binds to cells facing out. These spike trimers are mixed with a substance that stimulates the immune system ― an adjuvant ― to form nanoparticles. The spike proteins self-assemble into 3D structures that look like jacks, called “trimers,” which are purified from the cells. Once insect cells are infected, the cells read the instructions and create large amounts of spike protein. That gene is inserted into a virus capable of infecting insects but not people. Protein Nanoparticle Vaccine NVX-CoV2373Ĭreating the NVX-CoV2373 vaccine starts with identifying the genetic instructions for the spike protein. The protein vaccines are like a bakery cake - the spike proteins are delivered to the body. Think of it like this: the mRNA vaccine is like a cake recipe - the messenger RNA gives the correct amount of each ingredient to make SARS-CoV-2 spike proteins, but the body’s cells actually combine the ingredients and make the proteins. The difference is in how the spike proteins show up. All of the current COVID-19 vaccines in the U.S., and the nanoparticle vaccines, use the spike gene from the original Wuhan strain of SARS-CoV-2, the virus that causes COVID-19. These proteins, called spikes, are what dock on human cells ― a crucial step for infection. How Nanoparticle Vaccines WorkĬoronaviruses are named for their corona, or crown, of proteins. ![]() But other COVID-19 vaccines use protein nanoparticles as vaccines. More recently, the Food and Drug Administration approved messenger RNA (mRNA) COVID-19 vaccines that use lipid nanoparticles as a bubble around the genetic information they carry. The Mayo Clinic Vaccine Research Group, in collaboration with virologists worldwide, has worked on nanoparticle delivery for vaccines since 2015 for both the influenza H5N1 and Zika viruses. “They are the right size for immune cells to digest, they have the right chemical and electrical charge to be taken up by the immune cells, and they are capable of carrying proteins the immune system can learn to recognize.” “Much like Goldilocks and the porridge that is ‘just right,’ nanoparticles have many characteristics that make them very good at stimulating the immune system,” says Dr. Nanoparticles are a group of proteins or substances that measure between 1 and 100 nanometers. But what are nanoparticles? What are nanoparticle vaccines? And how could one vaccine provide immunity to multiple viruses? Richard Kennedy, Ph.D., an immunologist and co-director of Mayo Clinic’s Vaccine Research Group, explains. COVID-19 vaccine are bringing nanoparticle bioengineering technology into the news. ![]()
0 Comments
Leave a Reply. |