Helen Branswell 🇨🇦
@helenbranswell.bsky.social
I cover infectious diseases for STAT (www.statnews.com). 2020 Polk winner. Nieman '11. She/her. I write about H5N1 (in all species), Covid, polio, flu, Ebola, RSV, mpox, STIs. Find me on Signal: HBranswell.01
3. How bad this #flu season will be in the US is still anyone's guess. But if #H3N2 viruses play a big role the season could be tough; the H3 component in flu shots may not protect well against subclade K viruses.
Currently H3 is the major player & subclade K makes up more than 1/2 of H3 viruses.
Currently H3 is the major player & subclade K makes up more than 1/2 of H3 viruses.
December 1, 2025 at 11:54 PM
2. The UK, Japan, Hong Kong experienced very early starts to their #flu seasons due to the new #H3N2 variant, subclade K. But the US season doesn't seem unusually early; on par with the last couple of years. (I added the black bar here; when we're above it, we're officially in flu season)
December 1, 2025 at 11:54 PM
1. #CDC posted FluView for week 47 today; that's the week ending Nov. 22. We'll see in the next couple of weeks what Thanksgiving travel & gatherings did to amp up transmission of #flu in the US. As of just before Thanksgiving, activity was mainly low, though starting to pick up. See LA & CO.
December 1, 2025 at 11:54 PM
Just when you hoped it was over: #USDA reports that California has found another #H5N1 #birdflu infected dairy herd, its 773rd. There's been a total of 1083 confirmed herds in 18 states since March 2024. www.aphis.usda.gov/livestock-po...
December 1, 2025 at 4:53 PM
Just when you hoped it was over: #USDA reports that California has found another #H5N1 #birdflu infected dairy herd, its 773rd. There's been a total of 1083 confirmed herds in 18 states since March 2024. www.aphis.usda.gov/livestock-po...
A person in Washington State who kept backyard poultry has died from #H5N5 #flu. The person was the first known infection with this subtype of flu globally & the second recorded death in the US from an #H5 flu virus. Health authorities say there's no evidence the person spread the virus to others.
November 22, 2025 at 2:41 PM
6. There were no pediatric #flu deaths reported last week. 🙏
There was a report from Vermont of a person who contracted H1N2v, a #flu virus that circulates in pigs. Not clear how he/she caught the virus or whether any close contacts were also ill. The person recovered. www.cdc.gov/fluview/surv...
There was a report from Vermont of a person who contracted H1N2v, a #flu virus that circulates in pigs. Not clear how he/she caught the virus or whether any close contacts were also ill. The person recovered. www.cdc.gov/fluview/surv...
November 21, 2025 at 11:58 PM
6. There were no pediatric #flu deaths reported last week. 🙏
There was a report from Vermont of a person who contracted H1N2v, a #flu virus that circulates in pigs. Not clear how he/she caught the virus or whether any close contacts were also ill. The person recovered. www.cdc.gov/fluview/surv...
There was a report from Vermont of a person who contracted H1N2v, a #flu virus that circulates in pigs. Not clear how he/she caught the virus or whether any close contacts were also ill. The person recovered. www.cdc.gov/fluview/surv...
5. The UK & Japan had early starts to their #flu seasons, due to subclade K. But the start to the US season seems on a par with several recent seasons. The dotted red line is this season. When the dotted red curve crosses the black line (which I added), it's considered that flu season has started.
November 21, 2025 at 11:58 PM
5. The UK & Japan had early starts to their #flu seasons, due to subclade K. But the start to the US season seems on a par with several recent seasons. The dotted red line is this season. When the dotted red curve crosses the black line (which I added), it's considered that flu season has started.
2. As is generally the case with #flu, it starts to spread first among little kids. You can see activity in kids & teens (the top 2 lines) starting to climb sharply. If kids (or their parents) bring flu to Thanksgiving celebrations, the lines at the bottom of the graph will start climbing soon.
November 21, 2025 at 11:58 PM
2. As is generally the case with #flu, it starts to spread first among little kids. You can see activity in kids & teens (the top 2 lines) starting to climb sharply. If kids (or their parents) bring flu to Thanksgiving celebrations, the lines at the bottom of the graph will start climbing soon.
1. #Flu 🧵: #CDC reports that #influenza activity has been "trending upward slowly" in the US over the past few weeks. This could change markedly after Thanksgiving, with all the cross country travel & intergenerational mingling. Right now only 2 places are reporting moderate activity, LA & PR.
November 21, 2025 at 11:58 PM
1. #Flu 🧵: #CDC reports that #influenza activity has been "trending upward slowly" in the US over the past few weeks. This could change markedly after Thanksgiving, with all the cross country travel & intergenerational mingling. Right now only 2 places are reporting moderate activity, LA & PR.
#Marburg: Ethiopia's health ministry says at least 3 people have died from Marburg. The slide, posted to their X account, suggests there've been 4 confirmed cases. WHO has said at least 9.
Am curious about efforts to get experimental vaccine into the field. africannewsagency.com/ethiopia-rep...
Am curious about efforts to get experimental vaccine into the field. africannewsagency.com/ethiopia-rep...
November 18, 2025 at 5:35 PM
#Marburg: Ethiopia's health ministry says at least 3 people have died from Marburg. The slide, posted to their X account, suggests there've been 4 confirmed cases. WHO has said at least 9.
Am curious about efforts to get experimental vaccine into the field. africannewsagency.com/ethiopia-rep...
Am curious about efforts to get experimental vaccine into the field. africannewsagency.com/ethiopia-rep...
#CDC 's latest FluView reports that the number of pediatric #flu deaths in 2024-25 reached 287. That brings last season's total to 1 shy of the toll in the 2009 H1N1 #pandemic.
Flu can be hard on kids. Fortunately, there are vaccines that can mitigate severity. www.cdc.gov/fluview/surv...
Flu can be hard on kids. Fortunately, there are vaccines that can mitigate severity. www.cdc.gov/fluview/surv...
November 15, 2025 at 10:18 PM
#CDC 's latest FluView reports that the number of pediatric #flu deaths in 2024-25 reached 287. That brings last season's total to 1 shy of the toll in the 2009 H1N1 #pandemic.
Flu can be hard on kids. Fortunately, there are vaccines that can mitigate severity. www.cdc.gov/fluview/surv...
Flu can be hard on kids. Fortunately, there are vaccines that can mitigate severity. www.cdc.gov/fluview/surv...
[email protected], a pro- #vaccine physician, attended last weekend's gathering of anti-vax forces organized by Children's Health Defense. He thinks more colleagues should do the same — to understand what public health is facing. www.statnews.com/2025/11/11/c...
November 11, 2025 at 7:35 PM
[email protected], a pro- #vaccine physician, attended last weekend's gathering of anti-vax forces organized by Children's Health Defense. He thinks more colleagues should do the same — to understand what public health is facing. www.statnews.com/2025/11/11/c...
Idaho reported another #H5N1 #birdflu infected dairy herd recently, its 108th.
That makes 1,081 confirmed infected herds in 18 states since the outbreak was first recognized in spring 2024. www.aphis.usda.gov/livestock-po...
That makes 1,081 confirmed infected herds in 18 states since the outbreak was first recognized in spring 2024. www.aphis.usda.gov/livestock-po...
October 17, 2025 at 2:12 PM
Idaho reported another #H5N1 #birdflu infected dairy herd recently, its 108th.
That makes 1,081 confirmed infected herds in 18 states since the outbreak was first recognized in spring 2024. www.aphis.usda.gov/livestock-po...
That makes 1,081 confirmed infected herds in 18 states since the outbreak was first recognized in spring 2024. www.aphis.usda.gov/livestock-po...
Belatedly: #USDA announced that Nebraska has joined the states that have detected #H5N1 #birdflu in dairy cattle. Since H5 was first detected in cows in the US in spring 2024, 1,080 herds in 18 states have tested positive for the virus. www.aphis.usda.gov/news/agency-...
September 16, 2025 at 8:36 PM
Belatedly: #USDA announced that Nebraska has joined the states that have detected #H5N1 #birdflu in dairy cattle. Since H5 was first detected in cows in the US in spring 2024, 1,080 herds in 18 states have tested positive for the virus. www.aphis.usda.gov/news/agency-...
#CDC was alerted to 3 more #flu deaths in kids, bringing the total for the 2024-25 season (so far) to 278 — only 10 fewer than during the 2009 H1N1 pandemic. About 90% of those kids weren't vaccinated against flu. So tragic.
Kids should be vaccinated against flu.
www.cdc.gov/fluview/surv...
Kids should be vaccinated against flu.
www.cdc.gov/fluview/surv...
August 31, 2025 at 5:04 PM
#CDC was alerted to 3 more #flu deaths in kids, bringing the total for the 2024-25 season (so far) to 278 — only 10 fewer than during the 2009 H1N1 pandemic. About 90% of those kids weren't vaccinated against flu. So tragic.
Kids should be vaccinated against flu.
www.cdc.gov/fluview/surv...
Kids should be vaccinated against flu.
www.cdc.gov/fluview/surv...
The number of kids who died from flu in the 2024-25 season is still rising. #CDC was informed of another 5 deaths, bringing the season total to 275 so far. Deaths occurred in Jan & May.
The only time more peds deaths from flu were reported was in the 2009 pandemic. www.cdc.gov/fluview/surv...
The only time more peds deaths from flu were reported was in the 2009 pandemic. www.cdc.gov/fluview/surv...
August 23, 2025 at 2:37 AM
The number of kids who died from flu in the 2024-25 season is still rising. #CDC was informed of another 5 deaths, bringing the season total to 275 so far. Deaths occurred in Jan & May.
The only time more peds deaths from flu were reported was in the 2009 pandemic. www.cdc.gov/fluview/surv...
The only time more peds deaths from flu were reported was in the 2009 pandemic. www.cdc.gov/fluview/surv...
#CDC has been advised of another 3 children who died from #flu in the 2024-25 season, bringing the confirmed pediatric death toll to 270. This number could rise further; pediatric deaths are often reported months later.
Most weren't vaccinated.
This is beyond tragic.
www.cdc.gov/fluview/surv...
Most weren't vaccinated.
This is beyond tragic.
www.cdc.gov/fluview/surv...
August 15, 2025 at 3:12 PM
#CDC has been advised of another 3 children who died from #flu in the 2024-25 season, bringing the confirmed pediatric death toll to 270. This number could rise further; pediatric deaths are often reported months later.
Most weren't vaccinated.
This is beyond tragic.
www.cdc.gov/fluview/surv...
Most weren't vaccinated.
This is beyond tragic.
www.cdc.gov/fluview/surv...
Massachusetts announces the risk of #WestNile has risen to "high" in a number of municipalities at this point. Between #WNV and #EasternEquineEncephalitis or #EEE, this is a good time of the year not to be bitten by mosquitoes!
August 12, 2025 at 7:03 PM
Massachusetts announces the risk of #WestNile has risen to "high" in a number of municipalities at this point. Between #WNV and #EasternEquineEncephalitis or #EEE, this is a good time of the year not to be bitten by mosquitoes!
"Public health workers are not the enemy:" former surgeon general Jerome Adams on yesterday's alarming attack on the CDC. www.statnews.com/2025/08/09/c...
August 9, 2025 at 11:04 PM
"Public health workers are not the enemy:" former surgeon general Jerome Adams on yesterday's alarming attack on the CDC. www.statnews.com/2025/08/09/c...
#CDC has been informed of another pediatric #flu death in the 2024-25 season. That makes 267 children who died from flu this season. Such a tragedy.
90% of these kids (of those for whom vax status is known) weren't vaccinated, up from 82% in 2023-24. www.cdc.gov/fluview/surv...
90% of these kids (of those for whom vax status is known) weren't vaccinated, up from 82% in 2023-24. www.cdc.gov/fluview/surv...
August 8, 2025 at 3:26 PM
#CDC has been informed of another pediatric #flu death in the 2024-25 season. That makes 267 children who died from flu this season. Such a tragedy.
90% of these kids (of those for whom vax status is known) weren't vaccinated, up from 82% in 2023-24. www.cdc.gov/fluview/surv...
90% of these kids (of those for whom vax status is known) weren't vaccinated, up from 82% in 2023-24. www.cdc.gov/fluview/surv...
#USDA reports another #H5N1 #birdflu infected dairy herd in California, the 771st such detection in the state.
The cumulative national total of detected/confirmed herds is 1,078 in 17 states. The true number of infected herds? Who knows?
www.aphis.usda.gov/livestock-po...
The cumulative national total of detected/confirmed herds is 1,078 in 17 states. The true number of infected herds? Who knows?
www.aphis.usda.gov/livestock-po...
August 4, 2025 at 12:35 PM
#USDA reports another #H5N1 #birdflu infected dairy herd in California, the 771st such detection in the state.
The cumulative national total of detected/confirmed herds is 1,078 in 17 states. The true number of infected herds? Who knows?
www.aphis.usda.gov/livestock-po...
The cumulative national total of detected/confirmed herds is 1,078 in 17 states. The true number of infected herds? Who knows?
www.aphis.usda.gov/livestock-po...
Dallas County has reported its first confirmed case of #WestNile in 2025. Recently, MA's Public Health Dept reported the first finding of #TripleE — Eastern Equine encephalitis — infected mosquitoes this year.
Aug-Sept is when some nasty mosquito-spread diseases emerge. Be prudent: Use bug spray.
Aug-Sept is when some nasty mosquito-spread diseases emerge. Be prudent: Use bug spray.
August 1, 2025 at 8:02 PM
Tiny bit of good news: No new pediatric #flu deaths for 2024-25 were reported last week to the #CDC. First time in weeks that figure — currently 266 for the season — hasn't risen. However, 1 additional peds death for the 2023-24 flu season was reported last week, bringing that yr's total to 208.
August 1, 2025 at 3:23 PM
The NYC #Legionnaires outbreak has grown to 22 cases, with 1 death. Cases have been reported in Central Harlem (ZIP codes 10027, 10030, 10035, 10037 & 10039) & bordering communities. Sounds like cooling towers (multiple?) may be the source??? www.nyc.gov/site/doh/abo...
July 31, 2025 at 12:37 AM
The NYC #Legionnaires outbreak has grown to 22 cases, with 1 death. Cases have been reported in Central Harlem (ZIP codes 10027, 10030, 10035, 10037 & 10039) & bordering communities. Sounds like cooling towers (multiple?) may be the source??? www.nyc.gov/site/doh/abo...