Helen Branswell 🇨🇦

If you are making a break for other social media platforms, I am on Bluesky at @helenbranswell.bsky.social and on mastadon at @HelenBranswell@scicomm.xyz. And yes, they are pleasant places.

Subacute sclerosing panencephalitis is a rare but fatal side effect of #measles infection, which manifests years after a kid recovers. This story of a family who lost a 10-year old to it is heartbreaking. Renae was too young to be vaccinated when she caught measles. nytimes.com/2026/04/21/opi…

People at or concerned about #CDC want to be hopeful about the nomination of Erica Schwartz for CDC director. But the fact that she would report to Secretary Kennedy — who disdains the agency & undermines vaccine policy — gives them pause. statnews.com/2026/04/18/eri…

#Flu season is over but pediatric flu deaths continue to be reported to #CDC. In the week ending 4/11, four more deaths were reported, bringing the 2025-26 total to 143. About 85% of those kids weren't vaccinated. Sadly, this number will likely continue to climb. cdc.gov/fluview/survei…

#Measles: Confirmed cases in the US have hit 1748 so far this year. All but 10 are infections contracted in the US. For some context: In the first 3.5 months, 2026 has racked up 76% of the cases accrued in all of 2025 — the biggest year for measles since 1991. #cdc_data_surveillance_section_5-yearly-measles-cases" target="_blank" rel="nofollow noopener">cdc.gov/measles/data-r…

#CDC has been without a director for most of Trump 2.0. A new nominee was put forward today, Erika Schwartz, a former deputy surgeon general. (Nomination was scooped earlier this week by @ddiamond & @bylenasun ). Let's see what happens. statnews.com/2026/04/16/eri…

The next #WHO director-general will be selected in 2027 but candidates will soon start throwing hats in the ring. A name one hears as a possible candidate is Hanan Balkhy, director for WHO's Eastern Mediterranean region, who has a very challenging job these days. statnews.com/2026/04/14/nex…

It's not gone: #USDA reports 5 more dairy herds in Idaho have tested positive for #H5N1 #birdflu, the first in months. In the 2+ years since the virus was first detected in cows in the US, 1,093 herds in 19 states have tested positive for the virus. aphis.usda.gov/livestock-poul…

New rules for CDC vaccine panel aim to address lawsuit, empower Kennedy’s allies statnews.com/2026/04/09/new… via @statnews @HelenBranswell @AnilOza16

#Flu season is now officially over, but pediatric flu death reports continue to flow to #CDC. In the wk ending 4/4, CDC learned of 12 more kids who died from flu in 2025-6, bringing the total to 139. It will rise over coming weeks. CDC also belatedly learned of another death, the 296th, in 2024-5.

If you're interested in viruses — you kinda gotta be, if you're following me — this podcast may appeal. Deep dive into how viruses work, hosted by @florian_krammer, one of my go-to experts for flu. Lotsa detail, but the episodes are a manageable length. Enjoy! virological.podigee.io/episodes

@lenzhq @sciencecohen I have followed H5N1 for more than 2 decades. I have not and do not regularly see claims that there is sustained human-to-human transmission of the virus.

Fair point — the "sustained human-to-human transmission" question circulates widely in public discourse (news headlines, policy discussions), not from your article specifically. We should have been clearer about the claim source. Appreciate the pushback — accuracy in attribution matters.

2 years ago now the world learned US dairy cows were being infected with #H5N1 #birdflu, raising concern the virus would find a new route to move from animals to humans. Cow infections seem to have slowed & many questions remain, @sciencecohen reports. science.org/content/articl…

@lenzhq @sciencecohen Where did you see the claim you fact-checked in this piece? It's not sourced.

@HelenBranswell @sciencecohen @HelenBranswell For anyone following the H5N1 discussion — we checked the "sustained human-to-human transmission" claim against WHO, CDC, and ECDC data through March 2026. Conclusion: not happening yet. Full evidence: lenz.io/c/494045f5

The pause of Rabies & Mpox testing @CDCgov is a public health warning siren. It reflects a failure of current leadership to articulate that CDC is fundamentally a knowledge agency that brilliantly responds. While it is appropriate to discontinue outdated tests or those readily available elsewhere, these labs are an irreplaceable international resource. They must be supported for novel pathogen detection, the development of new diagnostics, and serving as a national reference laboratory. nytimes.com/2026/04/01/hea…

#CDC's website is updated.

On his 1st anniversary of starting as #FDA commissioner — & the 1st anniversary of FDA losing 3,500 staff in DOGE-ordered cuts — Marty Makary said FDA is trying to hire 3,000 scientists, inspectors & support staff. @LizzyLaw_ heard his address. statnews.com/2026/04/01/fda…

#NIH director Jay Bhattacharya is also overseeing #CDC, which still doesn't have a director, or even a director nominee working her/his way through Senate confirmation. But "acting director" is a title he can't wear. Not sure why CDC's website lists him thus. statnews.com/2026/03/25/cdc…

What could possibly go wrong? #CDC pauses support for states on testing for #rabies & #mpox because it doesn't have the personnel to do the work. 2 pathogens you really don't want to mess with, rabies & mpox. nytimes.com/2026/04/01/hea…

#PEPFAR, which changed the trajectory of the #HIV epidemic, "is being slowly starved, through budgetary choke points and administrative fiat," at risk of dying a death of a thousand cuts, @sciencecohen reports. science.org/content/articl…

Duikers — a variety of small antelopes prevalent in Central and West Africa — may be playing a role in the spread of #mpox, @kakape reports. science.org/content/articl…