Several working groups are studying a unique drug that protects against all variants and even future coronaviruses. And to block infection and transmission of the virus, nasal vaccines could be a solution
After two years of pandemic, the first Covid vaccines that entered the market, in particular those with Pfizer and Moderna mRNA, worked very well to avoid serious illness or death in most cases, averting great suffering. However before with the arrival of the Delta variant, but above all with Omiron, the effectiveness of the vaccine decreased significantly, so much so that it was necessary to introduce a booster. Vaccines are designed to recognize parts of the original Sars-CoV-2 Spike protein, but variants with multiple Spike mutations, such as Omicron, are able to better evade protectionwhile maintaining high efficacy against deaths and severe forms of disease.
Pfizer and Moderna have started clinical trials on the specific anti Omicron vaccine but the virus mutates very quickly: many scientists fear that by the time it is distributed, another strain will already have appeared. it is now clear that the virus will continue to evolve as it has done so far for this reason many researchers around the world are working to develop a universal anti Covid-19 vaccine, if not a universal coronavirus vaccine, the vaccine coronavirus bread able to offer protection not only on Sars CoV-2 but also on all known human coronaviruses (including the four that cause common colds).
The ambitious goal, but it could be decisive because the great advantage of these vaccines that they would allow to manage not only new variants, but also new coronaviruses that could emerge with other leaps of species. It will take years for these vaccines to be developed, but innovative approaches are needed to induce broad and lasting protection against known and as-yet-unknown coronaviruses, he warned. Anthony Fauci, immunologist, director of the National Institute of Allergy and Infectious Diseases in the United States and White House advisor on the pandemic.
In general the working groups that are dedicated to the vaccine sandwich must take into account regions of the virus little prone to mutations and which remain fairly stable across all coronaviruses. Pamela Bjrkman, a structural biologist at the California Institute of Technology is developing a universal vaccine for some Sars-like viruses. A vaccine consisting of more parts of the virus tested on mice it would stimulate the formation of antibodies by blocking infections caused by several Sars-like viruses, including strains that were not used to create the vaccine. Researchers are convinced that guinea pigs’ immune systems have learned to recognize the common characteristics of coronaviruses and human tests will begin shortly.
The nanoparticle in the shape of a soccer ball
The United States Army recently released promising results from a vaccine candidate called Spik Ferritin Nanoparticle (SpFN) developed by researchers from the Walter Reed Army Institute of Research. Current vaccines feature only one version of Spike but as has been seen the risk that the virus mutates and is no longer recognized. Instead, this vaccine is based on a technology developed to produce universal influenza vaccines and composed of a nanoparticle, Ferritin Nanoparticle (SpFN), shaped like a soccer ball with 24 faces decorated with multiple copies of the original SARS-CoV-2 spike protein.
The immune system stimulated by this type of vaccine develops neutralizing antibodies capable of countering the different variants and those that may arise in the future for this, scientists believe that it will be able to confer a broader protection than current vaccines. The presence of multiple coronavirus spike proteins on a multifaceted nanoparticle can stimulate immunity in a way that creates much broader protection, he said at a December press conference. Kayvon Modjarrad, one of the researchers working on the project
In vitro testing and pre-clinical animal testing (published in Science Translation Medicine) have achieved excellent results. The SpFN nanoparticle preparation based on a ferritin platform induces highly potent and broadly neutralizing infected antibody responses against the major SARS-CoV-2 variants of concern, including the SARS-CoV-1 virus which emerged in 2002 (not yet tested on Omicron).
Phase 1, which started last April, enrolled 72 adults between the ages of 18 and 55 and also in this case the results were defined as promising. Phase 2-3 trials involving more participants are expected to begin shortly to confirm safety and efficacy. The SpFN nanoparticle vaccine tested with a double dose after 28 days and a booster after six months. Unlike mRNA vaccines, the SpFN vaccine can be stored in the refrigerator at 2-8 for six months and at room temperature for up to six months.
Hunting for the Achilles’ heel
Duke University researchers also announced in April 2021 that their coronavirus vaccine was 100% effective in primate testing. Five months later, Duke and two other academic institutions – the University of Wisconsin and Brigham and Women’s Hospital in Boston – received approximately $ 36.3 million to fund continued development of pan-coronavirus vaccines. What we try to do is target a specific part of the virus, its “Achilles heel,” he said Kevin Saunders, director of research at the Duke Human Vaccine Institute. For a vaccine to work on different types of coronaviruses, that “Achilles heel” would have to be a part of the virus that remains uniform across variants and over time, so when viruses mutate, the part that the vaccine targets the part that doesn’t. changes, or changes little.
At the beginning of the pandemic, researchers began looking for antibodies that deactivated Sars-like viruses and examined the antibodies present in the frozen cells of a patient recovered from the 2003 Sars-Cov infection and another patient recovered from Covid-19. The researchers identified a potent antibody named DH1047, present in the cells of both patients. When we vaccinated non-human primates with our vaccine they generated these antibodies that look like DH1047, Saunders said. The vaccine injected into monkeys has been shown to be able to protect not only from Sars-CoV-2, but also from the infection of several other coronaviruses.
Nasal vaccines
Another promising approach represented by a new generation of anti Covid vaccines, the spray ones, which can induceimmunity in the mucous membranes
dell’respiratory system, stopping the infection in the bud in its entrance door, thus preventing the virus from starting its journey towards the lungs, perhaps contributing to the so-called sterilizing immunity, or the condition in which the vaccinated subject does not become infected and does not infect others.
A working group from Yale University published the results of its anti-Covid vaccine in the form of a nasal spray in the journal Science Immunology last December, which appears to be able to counteract variants of the virus. The best immune defense occurs in the virus entry routes, the immunologist said Akiko Iwasaki, which coordinates the research. The beauty of this vaccine that it not only provides important protection, but long-lasting immunity and T and B cells remain on the mucosal surface stressed. So far the drug has been tested on mice and human tests are awaited.
Altimmune, a US biopharmaceutical company, is developing a Covid-19 vaccine that is administered as a nasal spray, but it seems that the immune response triggered at the end of the human trial is significantly lower than hoped for after the encouraging results obtained with the animals. Also there Meissa Vaccines, a Californian company, has just started phase 1 trials after good results with animal testing.
January 30, 2022 (change January 30, 2022 | 13:11)
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