Hello from Nairobi.

This week we start with an incisive essay on how global public health might win back the narrative war around vaccines, trust, and misinformation. After that, well … let me just say that I really do try to take the “global” in global health seriously. I know that the United States is not the center of the world. 

But several of the most important stories I’m tracking follow the health consequences of Trump administration policies playing out across Africa, the Caribbean, and Iran. So, buckle up for a red, white, and blue edition.

My name is William Herkewitz, and I’m a journalist based in Nairobi, Kenya. This is the Global Health Checkup, where I highlight some of the week’s most important stories on outbreaks, medicine, science, and survival from around the world.

With that, as we say in Swahili: karibu katika habari — welcome to the news.

Global public health can win the narrative war

Measles is having a comeback. Vaccine skepticism is rising. And during the global pandemic, millions quickly turned against even basic public health protections. It’s pretty clear that somewhere along the way, public health started losing the narrative war. 

The question is, how does the field fight back?

That’s the focus of a fascinating essay by Steve Hamill in Health Policy Watch, one which I haven’t been able to stop thinking about since I read it. Hamill is a senior marketing and comms executive at Vital Strategies, which is a nonprofit focused on global disease prevention. 

Part of the problem, Hamill argues, is that for decades public health officials worldwide assumed that rational arguments, data, and scientific evidence would be enough to persuade the public. (And hey, for a time, it was!) But the era of institutional trust “dominated by elite opinion makers driving consensus” is over, he writes.

And now, as we face a media landscape “driven by algorithms, influencers, and coordinated narrative warfare,” public health must take a new approach. And that includes borrowing several, highly effective tactics from public health’s worst detractors.

I reached out to Hamill about his essay, and we discussed what the field needs to do differently to win back trust and attention. 

In our conversation, Hamill pointed to two realities about the modern media environment that ring especially true to me. One is that “we’re in an era of AI slop, where authenticity and trust in who the messenger is now matters even more than the message.” The other is that many persuadable people increasingly form their views about public health by “following culture, not evidence.”

Accepting those realities means recognizing that the battleground for public health is much less likely to be found in press conferences or government PSAs … and more likely to be found on TikTok, YouTube, or the broader “content creator sector.” And that, Hamill argues, is exactly where public health agencies need to start showing up.

Thankfully, Hamill says that engaging in this ecosystem is actually easier than ever. As advertisers have poured money into influencer marketing this decade, “the content creator sector has become much more formalized,” he says. Today, there are several platforms (like CreatorIQ, for example) that can connect public health agencies directly with a stable of appropriate influencers, at scale. 

Now, you might ask: Will YouTubers deliver perfectly calibrated public health messages the way officials might hope? Of course not. But Hamill argues that perfection isn’t the point. More important is that “we have to trust imperfect messengers who have social capital in the communities that we're seeking to reach,” he says.

That gets to another of Hamill’s points: Public health organizations worldwide must begin staffing the experts and allocating the budgets needed to compete in this new media environment. 

Specifically, that means staffing public health institutions worldwide with staff excelling in “public relations, community engagement, advertising and paid media, digital media production,” among other technical expertise, he says. For a field where "communications is rarely seen as a strategic competency,” that would be an enormous shift.

Hamill’s last point is that, offline, public health must stop broadcasting messages from the top down and start working through trusted voices inside communities. A major effort should be focused on “finding people in the communities that believe in the information that we are trying to propagate and working with them to give them the resources to bring that to scale within their community,” he says.

In many ways, this mirrors a key tactic of the MAHA movement: identifying communities that already share a concern and amplifying those voices until they dominate the conversation. The difference is that Hamill argues public health should use that same approach in service of accurate information and public good. 

And crucially, he argues, these voices are in the majority. “There are more moms who are scared that their kids are going to go to school with unvaccinated people than there are moms who are scared that the vaccine is going to give their kid autism,” he says.

A battle over Cuban doctors 

The Trump administration has been ratcheting up a pressure campaign on one of Cuba’s most valuable exports: doctors. 

Guyana and Jamaica just announced that they will pull the Cuban doctors from their countries this year, the Miami Herald reports. 

What’s the context here?

For decades, the Cuban government has sent hundreds of thousands of medical workers abroad through state-run medical missions. These programs have operated across the world but are particularly critical in parts of the neighboring Caribbean, where you can find Cuban clinicians staffing everything from hospitals to rural health clinics. Today, the program has more than 24,000 doctors working in 56 countries worldwide.

Why is the United States concerned about these doctors? Money. 

Governments hosting Cuban medical missions typically pay Havana directly, with the Cuban state then passing along only a portion of the salary to the doctors. While the Trump administration is framing the issue partly about “labor exploitation” of the doctors, most observers see the campaign as an attempt to squeeze one of the (financially beleaguered) Cuban government’s most reliable sources of foreign currency.

Last year, the Trump administration began leaning hard on the foreign governments hosting Cuban doctors, threatening to cancel visas for anyone working with or supporting the Cuban programs, alongside other consequences. And the threats are working beyond just Jamaica and Guyana. Honduras also cancelled its program this year, and Guatemala has begun winding down its mission.

But the health care reality is brutal. As Al Jazeera reported last year:

That reality prompted unusually blunt pushback from Caribbean leaders. The prime minister of Barbados has called the U.S. pressure “unfair and unjustified," and the prime minister of Saint Vincent and the Grenadines noted, “I will prefer to lose my visa than to have 60 poor and working people die.”

My takeaway?

The reporting suggests that this is a cold, geopolitical pressure campaign applied with little regard for the health care void it will create. (For example, the threats are not being paired with resources to replace those doctors.) 

Two things can be true at once: Cuba’s medical missions may enrich a terrible government in Havana, while the Cuban doctors themselves provide lifesaving care to communities that will be worse off without them.

Black rain in Iran

New Scientist is reporting that recent strikes that set oil facilities ablaze near Iran’s capital, Tehran, have produced an unsettling phenomenon: black rain. 

These “catastrophic scenes have raised concerns about threats to civilian health in Iran,” with “local people complain[ing] of their throats aching and their eyes burning.”

What exactly is black rain? It’s a byproduct of rain falling through heavily polluted air. Or, as Stanford University atmospheric scientist Mark Jacobson told me, it’s rain drops “filled with health-damaging, toxic air pollutants.”

He says the drops themselves appear black because the concentration of “soot particles is so high in Tehran's rain that no light penetrates” them, which is a sign of just how polluted the air above the city has become. (Keep in mind, this is a city with a population roughly equal to New York City’s.)

Ultimately, the toxic rain itself isn’t actually the biggest health worry for the city’s residents. As the article notes, “the biggest threat may be the smoke rather than the black rain.” 

One researcher quoted in the article put it plainly: “If you get raindrops on your skin, yes, there will be some potentially carcinogenic compounds on your skin, but you can wash that off … but very fine smoke particles in the air can penetrate deep into the lungs and potentially get into the bloodstream.”

A flawed flu forecast

Two weeks ago, we talked about the strange annual ritual behind the flu shot. Which is how each year the World Health Organization tries to predict which flu strains will dominate in the upcoming winter, so that vaccine makers can aim for that educated guess.

Well, the Associated Press is reporting new data that shows that last year’s guess was … a bit of a flop.

U.S. health officials say the 2025 to 2026 flu vaccine was only about “25% to 30% effective” in preventing adults from getting sick enough that they needed to go see a doctor. All told, it was “one of its worst effectiveness rates in more than a decade.” For reference, “officials generally are pleased if a flu vaccine is 40% to 60% effective.”

What went wrong? 

Oddly, this is actually a bit of good news. The culprit is exactly what we discussed two weeks ago: a fast-spreading branch of “the H3N2 flu strain,” which experts have already updated in next season’s vaccine. So, the problem has already been patched. 

One final takeaway: It’s worth noting that even a mediocre flu shot still matters. In the United States, at least 101 children have died so far this flu season. Of the deaths where vaccination status was reported, about 85% weren’t vaccinated. That’s not a coincidence. As Vanderbilt University vaccine expert William Schaffner told the AP, that flu shot may not stop every infection, “but it can prevent people from becoming severely ill and dying.”

Health aid as a cudgel 

Sorry, folks, not ending on a happy note this week.

Two weeks ago, we covered the state of the Trump administration's new “America First” global health deals in Africa. I had spoken with Dr. Paul Spiegel, who directs Johns Hopkins’ Center for Humanitarian Health, who, as I wrote back then, “warned about turning health aid into what is openly described by Washington as a transactional exchange.” 

Well, this week the New York Times published a staggering example of what that approach could look like in practice, in Zambia.

According to a draft State Department memo obtained by the paper, U.S. officials are considering withholding HIV assistance to Zambia unless the country expands access for American companies to its mineral sector. (For reference: Zambia is one of the countries most affected by HIV in Africa, with about 1.3 million people relying on daily treatment supported by the United States’ PEPFAR program.)

Here are two quotes from the memo (prepared for Secretary of State Marco Rubio) that really illuminate just how the officials view lifesaving HIV medicines as a raw, political cudgel.

My takeaway? When we spoke with Spiegel, we talked about why transactional aid deals make for fragile and ineffective public health policy. That's still true.

But beyond the practical consequences for individual programs, he also made a broader point about what we lose when we treat lifesaving programs as bargaining chips: the trust and goodwill that once made global health “one of America’s most powerful forms of soft power,” he said.

I’ll see you next week.

William

Thumbnail image by Universal History Archive / Getty Images