NOrovirus is spread throughout AmericaAccording to the U.S. Centers for Disease Control and Prevention (CDC), the current number of infections is higher than at the same time in more than a decade.
There is still no antiviral treatment or vaccine for this devastating but thankfully short-lived disease. But Moderna scientists are in the final stages of testing what could be the first such attack using mRNA technology against the virus. We will introduce what you need to know about norovirus and the current status of gastroenteritis vaccine development.
Why is norovirus so rampant now?
“Norovirus, commonly known as gastroenteritis, has been around for a long time and is the leading cause of gastroenteritis, or inflammation of the intestinal tract that causes vomiting and diarrhea,” said Edmund, a pediatric infectious disease specialist at Rady Children's Hospital. Dr. Milder says: and UC San Diego Health.
There are nearly 50 different subtypes, or genotypes, of norovirus, which vary depending on the year of outbreak. For the past decade or so, one version of the virus, called GII.4, has been responsible for most infections around the world. Things changed last year when GII.17 became a dominant stock. This is partially responsible for the current increase in cases, as most people who have been infected with other types of norovirus do not have as strong an immunity to this type of norovirus, making them more susceptible to the disease. There is a possibility that it can be explained.
norovirus symptoms
For most people, the infection causes intestinal symptoms such as vomiting, diarrhea, and dehydration. Although unpleasant, these symptoms usually do not require treatment or hospitalization and often last only a few days. But older adults and young children often develop more severe illnesses, with about 100,000 people hospitalized and nearly 1,000 people (mostly older adults and young children) dying from infections in the United States each year. It is mainly caused by dehydration due to inability to control infections. food and water, According to the CDC.
Is norovirus the same as other viruses?
No, there are various reasons. First, it doesn't take a lot of virus to make someone sick. For most viruses, it takes thousands of virus particles to make you feel sick, but only 10 before you develop the intestinal symptoms characteristic of a norovirus infection.
To make matters worse, the virus can survive for several days on surfaces like countertops and doorknobs because it's encased in a particularly tough covering. Hand sanitizer is not effective in killing norovirus. To remove as much of the virus as possible, you should wash your hands with soap and water for 20 seconds. Also, norovirus cannot be destroyed by high or low temperatures. The most effective way to kill viruses on contaminated surfaces is to use a dilute solution of bleach and water and let it sit on the surface for at least 5 minutes before wiping it down.
Why is norovirus vaccination still not available?
There are nearly 50 different versions of the virus, meaning “each genotype requires a different immune response for protection,” said Dr. Dolan Fink, director of therapeutics for gastrointestinal pathogens and bacterial vaccines. say. With Moderna. Therefore, any vaccine requires educated guesses about which strains are likely to circulate that year, similar to the strategy of updating influenza vaccines each season.
How close are we to developing a norovirus vaccine?
Moderna is currently enrolling 25,000 people around the world in a Phase 3 trial of its vaccine after early trials showed promising results. In these studies, people vaccinated with the mRNA shots developed antibodies that effectively blocked norovirus proteins in human intestinal cells in clinical tests. Those who received the placebo vaccine did not show the same antibody activity.
Moderna's vaccine candidate includes three different noroviruses to increase the likelihood that the vaccine is well matched to circulating strains. “It would be great if there were conserved regions within norovirus proteins that could be targeted, but this is not the case,” Professor Fink says. Rather, they believe that taking this multivalent approach should provide sufficient protection against severe disease. This is a strategy the company is also using with its multivalent mRNA influenza vaccine. The mRNA platform also allows scientists to change and update viral targets more quickly, making them ideal for pivoting when viral strains change seasonally.
Recently, targeting multiple viral proteins has been shown to be effective. One of the mRNA COVID-19 shots was a bivalent vaccine that worked against two different strains of the virus.
Fink said Moderna plans to finish recruiting volunteers in the spring and will follow them for at least six months. But it could take longer to get a full report on how effective the vaccine is in the real world. To do so, it is necessary to infect a certain number of people with the virus and evaluate its effectiveness. However, more data should be available as the vaccine is tested in different facilities around the world.
Can vaccination prevent norovirus infection?
Like COVID-19 vaccines, mRNA norovirus vaccine candidates are not designed to prevent people from getting infected. But in theory, the vaccine could prevent vaccinated people, especially young people and older people, from getting seriously ill or being hospitalized.
How can I protect myself from norovirus?
There are no antiviral treatments or vaccines yet, so the best way to avoid getting sick is to maintain good hygiene. Wash your hands frequently and avoid touching your face and mouth. If you get sick, you can still shed the virus for days or weeks after you feel better, so stay home to avoid infecting others.
