![]() ![]() Researchers at the University of Hong Kong recently reported another change with omicron: where it replicates in the body. ![]() What are your treatment options if you get Covid-19? That echoes a report from Pfizer that a third dose of its vaccine made it just as effective against omicron as the initial doses were against the original virus. Moderna reported this week that a half-dose booster of its mRNA vaccine raised antibody levels against omicron 37-fold, while a full dose raised antibody levels 83-fold compared to just the two initial doses. But their efficacy against omicron isn’t zero, and with booster doses, protection from the variant improves dramatically. Most Covid-19 vaccines are optimized to help the immune system target the SARS-CoV-2 spike protein, and the changes in omicron do seem to render the first generation of vaccines less effective. Masked pedestrians walk by a banner that reads, “Science will make the breakthrough,” in New York City on December 21. The Food and Drug Administration this week granted its first emergency use authorization for an oral antiviral drug to treat Covid-19, Pfizer’s Paxlovid, for high-risk patients. Other therapies like antiviral drugs should still remain as effective against omicron, since they act on how the virus replicates instead of targeting its outer structure.īut most of these drugs have to be administered in the early stages of infection, which often requires testing to confirm. So far, only sotrovimab, the monoclonal antibody therapy developed by GlaxoSmithKline, seems to be effective against omicron. These changes to the spike protein also make therapies that use antibodies - monoclonal antibodies and convalescent plasma - less effective. That may explain why omicron seems to cause more reinfections and breakthrough infections in vaccinated people compared to other variants. Because of these changes, antibodies have a harder time recognizing and sticking to omicron’s spike. There are mutations on other parts of omicron’s spike protein as well. Omicron’s mutations seem to increase its affinity for ACE2, allowing it to more efficiently infect cells, thereby increasing its reproduction rate and transmissibility. Within its spike protein, omicron has mutations in the part of the spike that connects directly to a receptor called ACE2 on human cells. Omicron has 36 mutations in its spike protein, compared to 10 in alpha, 12 in gamma, and nine in delta. This makes the spike protein critical for how the virus functions and for how the immune system stops it. Antibodies attach to the spike protein and stop the virus from causing an infection. This is the part of the virus that comes into contact with human cells, and a prominent target for the immune system. One of the most important areas is in the spike protein of the virus. These changes are manifesting in several key ways. There are close to 50 mutations in the omicron variant compared to the original SARS-CoV-2 virus detected in China in 2019. The mutations in the omicron variant make it more prolific, dangerous, and elusive ![]() Through studying the genetics of the variant, scientists hope to get more clues about where it came from and potentially prevent the next variant from catching the world off-guard. From its genetic origins to the way it infects people, omicron is unusual and perplexing. Researchers are now racing to understand the variant to anticipate its next moves, but it’s proving to be challenging. How bad omicron gets also hinges on how people respond to it, particularly when it comes to getting vaccinated or boosted. Yet in South Africa, it appears that its omicron wave has already peaked without heavy casualties. It’s not yet clear whether these traits will drive up hospitalizations and deaths to record levels in the US and beyond, but epidemiological models show that omicron is likely to have a heavy toll this winter. Omicron could therefore push the Covid-19 pandemic into its worst phase yet. “It’s the ability to evade immunity coupled with this really high transmission rate that are the two things that set this variant apart from all the rest that have come before,” said Andrew Pekosz, a professor of microbiology at Johns Hopkins University. This includes people who were previously infected or vaccinated against Covid-19. In places like South Africa and the United Kingdom where omicron has been spreading fast, Covid-19 cases have doubled every three days or less. It’s a stunning new twist to the pandemic saga that has countries scrambling to prepare. ![]() The omicron variant of the SARS-CoV-2 virus, discovered just a few weeks ago, is poised to dominate Covid-19 cases around the world. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |