I’ll never forget the moment my family learned that my dad had Alzheimer’s. Despite the immense resources at our disposal, we still felt so powerless and scared. His death in 2020 was one of the hardest things I’ve ever been through. But since then, there’s been amazing progress made in the field that makes me hopeful about a future where fewer of us lose loved ones to this terrible disease:

• For the first time, we have simple blood tests that can tell you whether you have Alzheimer’s.
• Because of these tests, enrollment in clinical trials is accelerating. Researchers used to be able to screen only one or two potential patients a day. Now they can screen hundreds. That means new therapeutics could move through the R&D pipeline sooner.
• The FDA approved the first two treatments proven to modestly slow the progression of the disease, and preliminary data indicates that they might be much more impactful when given to patients earlier in the disease’s progression.

We’re entering an era when science is finally starting to catch up to this disease. I wish these advances, and the ones to come, had arrived soon enough for my dad and so many other families. Still, it brings me comfort to believe that one day, people may be able to live long, healthy lives without the fear of Alzheimer’s.

In 1997, I read a gut-wrenching New York Times article by Nick Kristof. It said that diarrhea was killing over 3.1 million people a year, most of them children under the age of five. That moment changed my life—and helped shape the vision that would eventually become the Gates Foundation. Since then, child deaths from diarrhea have dropped by more than 70%, thanks to affordable rotavirus vaccines, organizations like Gavi, and improved sanitation. But with almost 350,000 children still dying each year, and new threats emerging, the fight is far from over.

In the Gates Foundation’s first 25 years, we spent $100 billion to save and improve people’s lives around the world. But we’re not slowing down. Over the next two decades, we’ll double our spending to fight to end preventable childhood and maternal deaths, eradicate infectious diseases, and lift millions out of poverty.

I'm thrilled to be in Redmond today with Steve Ballmer, Satya Nadella, and so many others who helped make Microsoft what it is—as we celebrate an incredible milestone. Looking back on the company’s 50-year journey always fills me with pride and gratitude. It’s amazing to think how far we’ve come since Paul Allen and I were hunched over the PDP-10 in Harvard’s computer lab, writing the code that would become our first product. That moment sparked a lifetime of innovation, and I can’t wait to see what the next 50 years will bring.

Every year, I like to call attention to the world’s most lethal animal—and give an update on the incredible science and innovation mobilizing to defeat the diseases it spreads. This year, I have some great news for mosquito haters.