Forecasters expect peak weekly hospital admissions per 100,000 of 10.9 for influenza, 2.5 for COVID-19 (up from 1.7 in September), and 22.5 for RSV in children under 5 (up from 19.9), with a combined peak of 16.4 around Jan 1, 2027 (50% prediction interval: Dec 20, 2026 – Jan 18, 2027).

The big change is the strain. In September, forecasters expected an H3N2-dominant season, with H1N1 at 35.1% of influenza A. They now put H1N1 at 60.4% (50% prediction interval: 37.3% – 79.3%). Flu arrived early, and almost all of it is H1N1: in the week ending October 10, 5.0% of clinical lab specimens tested positive for influenza, which CDC says is higher than usual for this time of year, and 96.4% of subtyped influenza A was H1N1. The forecast for the CDC season severity rating is 67.1% Moderate, 21.7% High (up from 19.0%), 9.2% Low or lower (down from 12.1%), and 2.0% Very High or higher.

For 2027, forecasters expect 4,225 (−6% since September; 50% prediction interval: 2,534 – 6,635) measles cases in the US and 3,685 (+12% since September; 50% prediction interval: 2,361 – 5,760) in Europe.

US cases keep climbing, now at 4,410 confirmed in 2026, up from 3,294 in September, with a large outbreak in Pennsylvania and 3 deaths. Forecasters expect 5,798 (50% prediction interval: 5,024 – 6,736) US cases by the end of 2026, with about 10.5% of them hospitalized. Europe stays quiet: 143 cases in August, and 2,335 over the 12 months through August. Forecasters put the chance that the US loses its measles elimination status before 2027 at 96%.

The outbreak in eastern DRC keeps growing and is now the second-largest Ebola outbreak on record. As of October 15, there are 9,235 confirmed cases and 4,444 confirmed deaths, up from 7,200 and 3,475 in early September. It has also spread beyond the region: Kenya has 9 confirmed cases, all in one family cluster, and Nigeria confirmed its first case on October 20, in a woman who had traveled from Uganda.

Forecasters have held the chance of a first US case before July 2027 at 10%. They expect >15,000 confirmed cases by the time the outbreak ends.

US detections remain low but haven’t stopped, with 56 confirmed animal cases in 2026, up from 49 in September, including new cases in New Mexico. On October 21, USDA confirmed the first US wildlife case, an elk on a game ranch in Pecos County, Texas. Forecasters now expect 77 animal cases (+57% since September; 50% prediction interval: 37 – 183) in 2027.

Detections within 100 miles of the border in Mexico continue, with 10 animals reported between October 16 and 20 alone, which keeps the risk of new spillover alive into next year.

France kept adding cases into October, reaching 162 locally acquired cases across 22 clusters as of October 12, up from 57 in September, plus 1 case in Italy. Forecasters more than doubled their forecast, to 233 locally acquired cases (50% prediction interval: 196 – 281) in 2026, up from 98.