Early H1N1 activity drives 2026-27 flu surveillance indicators<\/p>\n
Seasonal activity remains low nationally, but indicators have been rising since late August and are higher than typical for this point in the year.1 During the week ending October 24, 7.6% of 53,102 specimens tested in clinical laboratories were positive for influenza, and 98.9% of influenza A viruses subtyped by public health laboratories were A(H1N1)pdm09.1 Outpatient visits for influenza-like illness reached 2.4%, still below the national baseline of 2.9%, with increases among patients aged 0 to 4 and 5 to 24 years.1<\/p>\n
Pediatric flu hospitalizations and emergency department visits<\/p>\n
The share of emergency department visits with an influenza diagnosis rose among patients aged 0 to 4 and 5 to 17 years.1 Hospitals reported 6,100 laboratory-confirmed flu admissions for the week, and children aged 0 to 4 years had the second-highest admission rate (1.8 per 100,000) after adults 65 years and older.1<\/p>\n
In the FluSurv-NET network, the weekly hospitalization rate was the highest for this point in the season since 2010-2011.1 Cumulative rates were 3.2 per 100,000 among children aged 0 to 4 years and 1.0 per 100,000 among those aged 5 to 17 years.1 CDC estimates at least 1 million illnesses, 16,000 hospitalizations, and 900 deaths from flu so far this season, and FluSight forecasts project 4,800 to 23,200 flu admissions for the week ending November 14.1<\/p>\n
H1N1 subclade diversity, vaccine match, and antiviral susceptibility<\/p>\n
Most circulating H1N1 viruses belong to the D.3.1.1 hemagglutinin subclade, and CDC reports more genetic diversity among co-circulating A(H1N1)pdm09 viruses than it has previously observed.1 The agency says it is too early to know whether this will affect vaccine effectiveness. Early antigenic data are reassuring: 94.2% of 103 characterized H1N1 viruses were well recognized by antisera to the 2026-2027 vaccine reference virus.1<\/p>\n
On treatment, 8 of 354 H1N1 viruses tested (2.3%) showed reduced inhibition by oseltamivir, none showed highly reduced inhibition, and no viruses had decreased susceptibility to baloxavir.1 CDC recommends annual vaccination for everyone 6 months and older, urging those not yet vaccinated to do so now, and early antiviral treatment, particularly for patients at higher risk of complications.1 Because infants younger than 6 months cannot be vaccinated, their protection depends on vaccinated caregivers and household contacts.2<\/p>\n
References1. Centers for Disease Control and Prevention. Weekly US influenza surveillance report: key updates for week 42, ending October 24, 2026. FluView. Published October 30, 2026. Accessed November 2, 2026. https:\/\/www.cdc.gov\/fluview\/surveillance\/2026-week-42.html<\/a>2. Ferrara JR. Child dies of flu-related illness in San Bernardino County. KTLA. Published October 30, 2026. Accessed November 2, 2026. https:\/\/ktla.com\/news\/inland-empire\/child-dies-of-flu-related-illness-in-san-bernardino-county\/<\/a>3. Scripps News Group. Colorado confirms pediatric flu death as cases rise early this season. KKTV. Published October 16, 2026. Accessed November 2, 2026. https:\/\/www.kktv.com\/2026\/10\/16\/colorado-confirms-pediatric-flu-death-cases-rise-early-this-season\/<\/a> <\/p>\n","protected":false},"excerpt":{"rendered":"Early H1N1 activity drives 2026-27 flu surveillance indicators Seasonal activity remains low nationally, but indicators have been rising…\n","protected":false},"author":2,"featured_media":665032,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[163,85,46],"class_list":["post-665031","post","type-post","status-publish","format-standard","has-post-thumbnail","category-health","tag-health","tag-il","tag-israel"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/665031","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=665031"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/665031\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/665032"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=665031"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=665031"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=665031"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}