An infant in San Francisco has been diagnosed with measles — the city's first confirmed case since 2019. The child, who had recently traveled internationally, was too young to have been vaccinated. Infants typically can't receive the MMR vaccine until they're at least six months old, with the standard recommendation being 12 months.

Let's get the obvious out of the way: this isn't the baby's fault, and it isn't the parents' fault for not vaccinating a child who literally couldn't be vaccinated yet. As one SF resident put it plainly: "The infant cannot be vaccinated until six months and usually they don't recommend it until one year, so don't blame the infant. However, this is really bad."

And it is bad. Measles is extraordinarily contagious — one of the most transmissible viruses known to medicine — and an infant's immune system is nowhere near equipped to handle it. The real danger here is community spread. Herd immunity is what protects the most vulnerable among us: newborns, immunocompromised individuals, and the elderly. When vaccination rates dip, those shields come down.

Here's something most people don't think about: vaccine immunity can fade. Another local shared a useful reminder: "I was vaccinated with routine vaccinations but randomly discovered in my mid-30s I lost my measles immunity after a titer test and had to be re-vaccinated. Adults should get a titer test." That's genuinely good advice, and it costs very little compared to an ER visit.

Now, we're a liberty-minded publication. We believe in individual choice. But individual choice comes with individual responsibility — and that means understanding the consequences of your health decisions on the people around you, especially those who don't yet have the option to protect themselves. Freedom isn't a permission slip to be reckless with other people's kids.

The San Francisco Department of Public Health has posted a health advisory and resources on its website. If you're a parent of a young child, or if you haven't checked your own immunity status in a while, now's the time. One case doesn't have to become an outbreak — but only if people actually act.

Get your titers checked. Talk to your pediatrician. And maybe skip the international travel with a four-month-old unless you absolutely have to.