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A new Covid-19 variant is spreading. Here's what you need to know

A new Covid-19 variant is spreading. Here's what you need to know

CNN5 hours ago

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A new coronavirus variant is spreading in many parts of the world.
The variant, NB.1.8.1, has been identified as the cause of Covid-19 resurgence in China and several other Asian countries. Experts in Europe are predicting a possible increase in cases there.
A summer wave also could occur in the United States. According to the US Centers for Disease Control and Prevention, NB.1.8.1 already represents about one-third of new Covid-19 cases as of June 7. This is a significant increase from just a month before, when the new variant represented just 5% of new Covid-19 cases.
Could another summer wave really occur? Do current vaccines still work, and if so, who should consider getting another dose now? And what precautions should people take to reduce their risk of contracting Covid-19?
To help us with these questions, I spoke with CNN wellness expert Dr. Leana Wen, an emergency physician and clinical associate professor at the George Washington University. Wen previously served as Baltimore's health commissioner.
CNN: What should people know about the new variant?
Wen: The SARS-CoV-2 virus is constantly mutating, and it's entirely expected that there will be new variants. The more opportunities the virus is given to spread, the more opportunities it has to mutate.
Every time a new variant arises that appears to be outcompeting previous strains, it's important to ask three questions: Is it causing more severe disease, is it more contagious, and do existing vaccines still work against it?
This new variant, NB.1.8.1, also called Nimbus, is a descendant of the Omicron strain. The World Health Organization has deemed the new strain a 'variant under monitoring.' However, WHO also reports that surveillance data do not show that it has increased severity compared with previously circulating variants. Given that this strain is outcompeting previous variants, it's possible that it could be more contagious, but there is nothing to suggest that it is being spread differently compared with past variants.
As for whether existing vaccines work against this variant, the answer is not known. WHO cites laboratory data showing that it could have some immune escape, which means it may be less responsive to the immunity provided by vaccines or prior infection and suggesting a possible reduction in vaccine efficacy. At the same time, NB.1.8.1 is a close descendant of other strains against which the vaccines have efficacy.
I expect there will be more data available in the coming weeks, as federal health officials will soon decide the formulation of this fall's updated Covid-19 vaccine. Knowing that NB.1.8.1 constitutes a growing proportion of cases, they will most likely try to ensure that the formulation has efficacy again this variant.
CNN: What are symptoms of N.B.1.8.1 infection?
Wen: The symptoms appear to be similar to infection with other variants. There is a large range of symptoms and severity. Some patients may have allergy-like symptoms, such as stuffy and runny nose. Others may have cold- or flulike symptoms, with fever, sore throat, fatigue, headache and muscle or body aches. Some people may develop cough and difficulty breathing. Some may have nausea, vomiting or diarrhea.
While most people will recover, some could become severely ill and require hospitalization. Some individuals who contract Covid-19 may also develop the post-viral condition known as long Covid.
CNN: Could another summer wave really happen again?
Wen: Yes. It could be triggered by a new variant that's more contagious and that has some degree of immune escape. A wave also could occur simply because of declining population immunity. Some experts believe that the emergence of this new strain combined with less recent Covid-19 activity could start a wave in the next couple of months.
What we have seen from several years of experience with Covid-19 is that infections tend to come in waves. A surge in cases leads to many people falling ill, then recovering and developing short-term immunity to infection. Infection rates decline for several months, then they begin to increase again.
Summer waves of Covid-19 have occurred over the past few years. It's certainly possible that the pattern repeats this year.
CNN: Who should consider getting the vaccine now instead of waiting for the fall formulation?
Wen: This is a difficult question to answer because the landscape around Covid-19 vaccination has been changing. Just last month, US Health and Human Services Secretary Robert F. Kennedy Jr. announced that Covid-19 shots are no longer recommended for healthy children and pregnant women. These shots appear to still be accessible for children; for instance, the CDC's guidance now reads that children can get the shots after consulting with their health care provider. However, there are already reports of pregnant women having more difficulty obtaining these vaccines.
This and other guidance could soon change, as Kennedy has reconstituted the panel of external experts who advise the CDC on vaccine recommendations, and this new panel could make different decisions during their upcoming meeting in late June. Another uncertainty is when a new round of vaccines will be made available.
One way to approach this decision is to consider your risk of severe outcomes if you were to contract Covid-19. Those who are 65 and over or who have chronic underlying medical conditions should consider getting another dose of the vaccine now, if they are eligible. That way, they have additional protection in case there is a summer wave, since the existing vaccine probably retains some efficacy against the new variant. And they can still get another dose in the fall when the new formulation will presumably be released.
As for those who are younger and generally healthy, some who have not yet received the 2024-25 formulation also may consider getting the vaccine now before guidelines change and they may no longer be eligible. People should discuss their specific medical situations with their primary care physician.
CNN: What precautions should people consider to reduce their risk of contracting this variant?
Wen: The same precautions we've been discussing throughout the Covid-19 pandemic still apply. This is a respiratory virus that could be airborne, so be on guard, particularly in crowded indoor settings.
People who are especially vulnerable to severe disease should try to avoid these settings. If they need to go into, say, a crowded train station, they should consider wearing a well-fitting N95 or equivalent mask.
Those people visiting vulnerable individuals may wish to avoid higher-risk settings in the days before the visit to reduce the chance of spreading not only Covid-19 but also other respiratory illnesses.

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The company hasn't revealed how much of a setback it might be for the vehicle or its launch facilities. Preliminary data suggested the explosion was caused by a gas tank that exploded, Musk said in a social media post. The tank 'failed below its proof pressure,' he said, meaning that prior stress tests and the known properties of the tank suggested it should have survived the scenario. It's potentially a unique problem that has never been observed before. During his May 29 speech, Musk emphasized that introducing even more upgrades and further stretching Starship's size is crucial to long-term success. 'It takes three major iterations of any major new technology to have it really work well,' Musk told employees during his Starship update. Musk has said he hopes the updated Starship will make its flight debut by the end of the year. But even if the new version pulls off a pristine test flight along the same suborbital route where SpaceX has carried out previous Starship test missions, it won't guarantee the vehicle is ready for an interplanetary excursion. That's because, even with added fuel capacity, Starship must be topped off with more propellant after it reaches space to make the long trip to Mars. SpaceX plans to do this by launching a series of tankers, or Starship vehicles designed to carry batches of fuel and oxidizer. Those tankers would rendezvous with the Starship while it idles in Earth's orbit, transferring thousands of pounds of propellant and delivering the fuel the vehicle needs to continue its journey deeper into the solar system. Notably, transferring fuel between two vehicles in space has never been done before. 'We've never done that. Nobody's done that — transferring fuel from one spacecraft to another in orbit autonomously,' said Bruce Jakosky, a professor emeritus of geological sciences at the University of Colorado Boulder's Laboratory for Atmospheric and Space Physics. 'That's difficult,' Jakosky added, especially considering the Starship vehicle runs on cryogenic fuels — essentially oxygen and methane that are kept at temperatures so cold they liquify. And in the microgravity environment of orbit, that fuel can float about in its tank rather than settling in one place. So, among myriad other technical difficulties, SpaceX will likely have to devise pumps or motors that can effectively funnel the fuel from one ship to another. Currently, it's not even clear how many tankers SpaceX would need to launch to give one Starship vehicle enough gas for a trip to Mars. (In prior estimates, NASA personnel and third-party experts projected it may take roughly one dozen Starship tankers for a moon mission.) In his speech, Musk said that he believed in-space fuel transfer would be 'technically feasible.' SpaceX will not attempt to carry out its first tanker flight test before next year, Musk added. Even after SpaceX sorts out the propellant transfer problem, they'll face another significant technological question: How will Starship survive the trip down to the surface of Mars? Musk last month called this issue 'one of the toughest problems to solve.' 'No one has ever developed a truly reusable orbital heat shield so that is extremely difficult to do,' he said. 'This will be something that we'll be working on for a few years, I think, to keep honing.' Vehicles that need to safely land on planetary bodies while traveling at orbital speeds must have a component called a heat shield — a special coating on the vehicle's exterior that serves as a buffer to the scorching temperatures generated by the process of entering a planet's atmosphere. On Mars, one crucial problem is the air: It's almost entirely made up of carbon dioxide. When Starship slams into Mars' atmosphere, it will violently compress the air in front of it and create searing temperatures. And the conditions of reentry are so intense that the process literally rips electrons away from atoms and splits molecules, turning the carbon dioxide into carbon and oxygen — the latter of which may start to 'oxidize' or essentially incinerate the spacecraft's heat shield, Musk said. Reentry on Mars will actually produce more heat-shield-destroying oxygen than the process of returning to Earth, Musk noted. Starship's heat shield will ultimately need to be durable enough to survive both types of reentry, potentially multiple times. While the odds of SpaceX solving all the necessary technical quandaries in time to send a cargo-filled Starship to Mars at the end of next year are likely small, even larger problems must be solved later down the road. If SpaceX wants to send humans to the red planet, for example, the company must figure out how to ensure Starship's exterior can keep people safe from the deadly radiation that will shower down throughout the six-month journey. Life support systems with plenty of breathable air would need to be on board. As Musk put it, every single human need must be accounted for. 'You can't be missing even, like, the equivalent of vitamin C,' he said. Once a Starship vehicle reaches its destination, it would likely need to top off its fuel at a Martian depot before returning home — another feat that presents enormous technological challenges. The idea that enough infrastructure will exist on Mars by 2029 — or 2031, as Musk has said in prior social media posts — to make such a crewed mission possible is outlandish. Still, industry experts say SpaceX's bold ambitions spark both excitement and skepticism. 'I am a fan of what SpaceX is trying to do. I totally subscribe to this vision of a multi-planetary society,' said Olivier de Weck, the Apollo Program Professor of Astronautics and Engineering Systems at the Massachusetts Institute of Technology. 'But it's a logistical problem first and foremost. And what's lacking to me is the thought about the cycling, the fuel production — and the return to Earth.' But Phil Metzger, a planetary physicist with the Florida Space Institute, emphasized that SpaceX does tend to deliver on its promises, even if it's a few years behind schedule. 'I feel like they got unlucky on some of their (Starship test flight failures), having the types of failures they had the last three in a row,' Metzger said. 'Considering their design and development philosophy, I think they're still within the window of expected outcomes.' But, Metzger added, 'we're reaching the point where you start to worry.'

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