Technologies

After 2 years of the COVID pandemic… we still have big questions

We’ve learned a lot about masks, quarantines and spike proteins in the past two years. We still don’t know enough about long COVID, vaccine protection and the origins of COVID-19.

For the most up-to-date news and information about the coronavirus pandemic, visit the WHO and CDC websites.

In December 2019, a group of people in Wuhan, China, began to experience what was described as an unknown pneumonia, later identified as COVID-19, which quickly blanketed the globe. To date, there have been 280 million infections to date, resulting in 5.4 million deaths.

Since then, advances against SARS-CoV-2, the virus that causes COVID-19, have come rapidly: Multiple effective vaccines emerged in a single year, far faster than the typical four to 10 years of development. And Pfizer has just received FDA authorization for its COVID antiviral drug Paxlovid, which the pharmaceuticals giant says could cut the risk of hospitalization or death from COVID-19 by up to 89%.

Infectious disease experts have discovered much about the science of COVID-19 and can now quickly identify mutations, like those found in the delta and omicron variants.

However, two years on, as the US passes 800,000 deaths from COVID — and tens of millions more infections and hospitalizations — scientists are still struggling to answer some of our biggest questions. For additional information on COVID-19, here’s what we know about the new omicron variant and how to get free at-home testing kits. And be sure to learn how to put your vaccine card on your phone.

Why does COVID make some people more sick, including long COVID?

We know the virus causes symptoms ranging from headaches, fever and disorientation to nausea and vomiting, and even loss of taste or smell. While scientists continue to piece together who is more likely to get hit with these outcomes, they still lack answers about why some experience serious illness and others don’t.

Age is definitely the biggest correlation for severe disease, Gigi Gronvall, a senior scholar at the Johns Hopkins Center for Health Security, told CNET. «But there have been 29-year-olds who have died, children who have died, when all indications suggest they should have had a mild disease course.»

Scientists are also trying to get their arms around «long COVID» — a range of symptoms that can run on for weeks or even months after a patient is first infected. The World Health Organization has issued a definition that includes a variety of lingering symptoms — including fatigue, trouble breathing, sleeplessness, difficulty focusing, anxiety and depression — and the list keeps changing. Even so, the condition’s cause is not clearly known.

«After two years, we don’t understand much about long COVID, and don’t know its prevalence with omicron after vaccination,» Bob Wachter, the chair of the department of medicine at the University of California, San Francisco, tweeted Wednesday. «It remains a hardship for millions, and a lingering concern for me as I think about the prospect of getting even a ‘mild’ case of omicron.»

While some general symptoms, like loss of smell and taste, appear less common with omicron, Gronvall said, «we just don’t know if people with that variant will suffer long COVID. We just haven’t had enough time to tell.»

How long will immunity from vaccines last with variants like omicron?

The first COVID-19 vaccines went into arms a year ago in the US, and the two most effective in the US — from Moderna and Pfizer/BioNTech — took a unique approach: Using Messenger RNA (mRNA) to teach our cells how to make a protein that will trigger an immune response to the virus.

While researchers have been studying mRNA vaccines «for decades,» according to the CDC, this marks the first time they’ve been made available to the public. Scientists continue to gather information on how effective they are — and how long until their effectiveness begins to decline.

«We are definitely still figuring that out,» Gronvall said. «We’re seeing that protection wanes earlier than six months, which is why boosters are being recommended at six months.»

As new variants like the quick-spreading omicron emerge, she added, «whether the booster will be sufficient for a long period of time or not is something we still need to uncover.»

According to the World Health Organization, the Pfizer and Moderna vaccines are far less effective in preventing infection by the omicron strain than earlier COVID-19 variants. Other vaccines — including those from Johnson & Johnson, AstraZeneca, and ones manufactured in Russia and China — do even less to prevent infection by the omicron variant, The New York Times reported.

Still, fully vaccinated individuals are much less likely to experience severe symptoms, hospitalization and death, according to Harvard Medical School, especially if they receive a booster shot.

«It’s not a worst-case scenario, where the vaccines are ineffective,» Gronvall said. «In lab scenarios we’ve seen, vaccines provide less protection. That seems to be borne out in reality, but we can’t project yet into the real world.»

Will there be more variants like delta and omicron?

Viruses constantly mutate. Sometimes these mutations result in new disease strains that emerge quickly and disappear, according to the CDC. Other times, they persist and create spikes in the rate of infection and disease. In two years, COVID has mutated into five «variants of concern,» according to WHO, based on the severity of disease, the effectiveness of medical countermeasures and the strain’s ability to spread from person to person.

The alpha, beta and gamma variants were all downgraded to «variants being monitored» in September, with delta and omicron still considered variants of concern. This week federal health officials declared the omicron variant the dominant strain in the US, accounting for nearly three-quarters of new infections. Preliminary studies indicate illness caused by omicron may be less severe than delta, which doubled the hospitalization rate of the original alpha strain, but is also far more contagious.

Health officials warn that the longer the pandemic lasts and the longer large groups remain unvaccinated, the more time the virus will have to spread and mutate. While researchers can quickly map and identify variants, they need time to see how dangerous a new strain is as they gather data on hospitalizations and deaths.

«We’re still not great at looking at new variants and projecting what that means in the real world,» Gronvall said. «We have better tools to read genetic material and determine when variants emerge. But we can’t read them like a book.»

Where did COVID-19 come from?

Experts are still not certain how COVID-19 emerged. The prevailing theory is that it leaped from an animal to a human. The first symptoms of COVID-19 were reported in Wuhan among people who either worked or lived near Huanan Seafood Wholesale Market, an open-air «wet market» that sold fresh beef, poultry, fish and produce.

According to numerous sources, including a June 2021 study in Scientific Reports, the market also traded in exotic animals as pets and food, including badgers, hedgehogs, civets and porcupines.

Others, however, claim that SARS-CoV-2 emerged in a lab — with a naturally occurring or human-engineered virus infecting a researcher, who spread it to others. While there has been no solid evidence to back the lab-leak theory, former President Donald Trump and his supporters pushed the lab-origin theory through 2020.

«There’s a lot of people using this as a vehicle for other agendas,» Gronvall said. «And certainly the Chinese have been lying.» Government officials originally claimed that there were no contraband animals present at the market, she added, but researchers looking for a separate tick-borne disease photographed many illegal animals there, «stuffed together in close quarters, in poor health and stress conditions, in the months before cases were identified.»

«People are looking to blame [someone],» Gronvall said. «They’re not looking for an explanation that is very human and plausible. But there’s no virus that’s been identified in the laboratory that’s at all close to what ended up spreading around the world.»

Because the Chinese government shut down the Huanan market and removed all evidence almost as soon as cases of COVID were being associated with it, Gronvall said, researchers are not likely to ever find the exact animal culprit.

«It wasn’t like SARS in 2003, when you had these palm civets there that were all infected and it was a pretty quick thing,» she said.

To uncover more about the emergence of COVID-19, this summer, President Joe Biden directed the federal intelligence community to «redouble their efforts» to investigate the virus’ origins.

What we do know, heading into the third year of the disease, is we have a medicine cabinet of tools — including vaccines and antiviral pills — we didn’t have when we first learned of COVID-19. For more, here’s what we know about the Moderna and Pfizer vaccine boosters and how to pick which one to get.

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.

Technologies

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Technologies

Camera Champions Face Off: iPhone 16 Pro vs. Galaxy S25 Ultra

When photo quality is a top consideration, the best phones from Apple and Samsung are amazing. But which is better? It’s time to find out.

When you’re looking for the best camera to carry in your pocket, you need to consider today’s top-tier phones. The imaging capabilities of the iPhone 16 Pro and Galaxy S25 Ultra are among the best money can buy. And with travel season ramping up, carrying a phone may be the most convenient camera. But for photo details how do these two mobile titans compare?

To find out, I shot hundreds of photos using both phones in a variety of conditions to see which phone takes the best-looking images. What’s «best» is often down to personal perspective so while I’ll be giving my personal take on each test as a professional photographer and giving my reasons why I prefer one over the other, you may well find that you prefer the other. So have a look through the range of examples here and see if you come to a different conclusion.

Read more: Best Camera Phone of 2025

All images shown have been taken using each phone’s default camera mode using default settings, unless otherwise stated. While images from the Galaxy S25 have been uploaded as taken, the iPhone’s images have had to be converted through Adobe Lightroom as our publishing platform doesn’t support Apple’s default HEIF image format. This process doesn’t affect the image in any way.

Ready? Let’s dive in.

Starting out with an easy outdoor scene. Both phones have done a great job capturing an even exposure here and both images are packed with detail. It’s difficult to choose between them, but the iPhone has the edge for me as it’s achieved a slightly warmer image with more natural-looking tones. The S25 Ultra’s image looks too saturated, especially in the blue sky, which I find quite distracting.

It’s much the same story when we switch to the ultrawide lenses on both phones. I prefer the warmer tones in the iPhone’s shot, which makes the S25 Ultra’s look quite cold by comparison. I also prefer the lighter shadows on the iPhone’s image, making it an easy win for the iPhone here. Notably, both phones are doing a good job of compensating for the ultrawide lenses at the edges (a function turned on by default on both phones); the railing remains straight in each shot and not curving as you’d typically see using a lens this wide.

There’s almost no difference between these two outdoor scenes. The blossom looks crisp on both images, with excellent overall exposure. The iPhone’s image is again slightly warmer in tone but it’s negligible.

The Galaxy S25 takes an easy win with this image of bluebells. The colors are much more vibrant, especially in the greens on the blades of grass, which look quite washed out on the iPhone’s image. It actually looks like the S25’s camera lens is slightly polarized to reduce reflections and increase saturation, but I don’t know if that’s the case. Either way, Samsung takes the win here.

At 5x zoom things get worse for the iPhone. Despite the bluebells being reasonably far away, the phone seemed unable to achieve a sharp focus on the flowers. The S25 Ultra, meanwhile, managed to achieve a sharp image with richer colors.

I prefer the iPhone’s image here though. It’s brighter and the warmer colors on the bricks on the surrounding buildings look much more true to life.

The iPhone’s image is again brighter here and I prefer its colors too. The Galaxy S25 Ultra does have the edge in fine detail, though. You really need to zoom in to see it but the tiny lines on the building are slightly sharper on the S25.

The S25 Ultra does have a physical advantage over the iPhone with its 10x optical zoom lens, which allows it to zoom in even further while still maintaining a pin-sharp image.

You can still digitally zoom in with the iPhone to 10x, and the results aren’t bad. I prefer the colors of the S25 Ultra’s shot here, but the difference in detail isn’t that noticeable.

Zooming in close to see the fine details, the S25 Ultra’s optical zoom image definitely has a bit more clarity but the digital upscaling on the iPhone’s shot has done a great job here, as the difference isn’t immense.

iPhone 16 Pro vs. Galaxy S25 Ultra: Night modes compared

At first glance, the only real difference between the iPhone’s 5x shot and the S25 Ultra’s 5x shot is the color balance. And honestly, I don’t have a preference between the warmer tone of the iPhone or the more magenta bias of the S25.

However, when you zoom in close to the details, the iPhone has produced a sharper image here, with an odd sort of digital blurring around the lamp post in the S25 Ultra’s image. So sometimes the S25 Ultra’s zoom is sharper, other times it’s the iPhone’s. I’m glad they’re making this easy for me.

Again, the only real difference here is in the color balance and I don’t really know which I prefer. The exposure, noise levels and amount of detail are practically identical.

Things changed when I switched to the ultrawide lenses, though. The S25 Ultra’s shot is definitely brighter, capturing more detail in the cobblestones in the foreground and in the buildings in the distance. The iPhone’s image is much darker overall.

Just to confuse things further, the iPhone’s nighttime image with its ultrawide lens is noticeably brighter than the S25 Ultra’s in this example that I shot in the Arctic. I actually had to double-check the image metadata to make sure I hadn’t mixed these up, but I haven’t. The iPhone’s image has captured more light information here and produced more detail on the ice door to the right.

The iPhone’s nighttime image is again slightly brighter here but it’s also kept the bright highlights on the pub sign under control. On the S25 Ultra’s image, those highlights are almost lost to pure white but the lovely green and yellow tones have been retained in the iPhone’s image. The colors overall are noticeably warmer on the iPhone’s shot, however, which may not be to your taste. Here, I think they work well.

But in this example, the iPhone has produced a weirdly warm-looking image that I really don’t like. Those warm colors were not present at the time of capture and it doesn’t work for the scene, especially not with such strong orange tones in the sky. The S25 Ultra’s image is much more balanced overall and it’s a slightly sharper image too. It’s a very easy win for Samsung here.

Things don’t improve for the iPhone when using the ultra-wide lens. Its image is again plagued by overly warm tones, while the S25 Ultra’s shot is both more color-accurate and brighter.

iPhone 16 Pro vs. Galaxy S25 Ultra: Which takes better selfies?

While the Galaxy S25 Ultra’s selfie is slightly brighter, I don’t like what it’s done with the colors. My face has been made a weird shade of orange and my denim jacket is a much deeper blue than it really is. The skin tones on the iPhone’s shot are much more accurate, and its shot is sharper as well.

Both phones have a wider-angle mode for the selfie camera, although the iPhone’s seems to be a lot wider. That’s definitely worth keeping in mind if you frequently like to cram lots of friends into your group pics. You could probably squeeze at least one or two extra friends in if you used the iPhone, or have to decide who you like least and leave them out of frame if you used the S25 Ultra. Otherwise, the image differences are the same as before.

iPhone 16 Pro Vs Galaxy S25 Ultra: Which camera is better?

I’ve written many of these comparison pieces on various generations of phones in my 14 years at CNET and I don’t remember having done one that’s felt this close. The problem is that neither phone excels consistently in one area; the iPhone 16 Pro’s ultra-wide shots aren’t as bright as the S25 Ultra’s, except on those occasions when they actually are, confusingly. I’ve taken many more images not included here that both support some of my conclusions and argue against them. Go figure.

But there are some takeaways I can give with confidence. Generally speaking, the iPhone’s colors are more natural than the S25 Ultra’s, which can sometimes look overly saturated. This has been the case with almost every Samsung phone since the company started putting cameras in them and it’s still the case today. Those looking for a more natural base image to apply your own filters and effects over will be better suited with the iPhone 16 Pro.

But that’s less the case at night, when the iPhone more consistently delivers warmer tones that look less natural than the S25 Ultra’s. So, if night photography is important to you, the S25 Ultra may be the better option. Overall, its night mode images from all lenses were brighter and sharper.

Sure, the S25 Ultra has the extended zoom range but you’d really need to know you’ll make the most of a 10x zoom to justify picking one over the other. Personally, I find the 5x zoom level a perfect sweet spot and here the phones are pretty much on par. And on those rare occasions you may want to push things further, the iPhone’s digital zoom can still deliver sharp results.

There are other things for photographers to consider too: Apple’s ProRaw is superb and while the company’s Photographic Styles can be good for adding a creative look to your images, Samsung’s new tool for mimicking the color grade from example photos you feed it works surprisingly well — I actually think I might get more use out of that overall. I haven’t even gone into video quality either, which is a whole other article, especially when you consider both phones shoot Log video, although only the iPhone uses ProRes.

Deciding between the phones based solely on the cameras is nigh on impossible. Which one you should get will instead come down to the bigger question of iOS versus Android; which platform you’re already using and which one will work best with other pieces of tech in your life. But for simple picture quality, you may as well toss a coin.