2,777 measles cases, low flu activity: the fall vaccine checklist for U.S. families (2026)

The short version

The week of August 17–24 leaves U.S. families with two practical jobs: check measles records and put fall flu vaccination on the calendar.

CDC reported 2,777 confirmed U.S. measles cases as of August 20. Seven percent of cases had required hospitalization, 94% were in people who were unvaccinated or whose vaccination status was unknown, and CDC reported no deaths. Two documented MMR doses remain the strongest routine protection. 1

Flu activity stayed low in CDC FluView Week 32, which ended August 15. Clinical laboratories found influenza in 0.7% of tested specimens, outpatient visits meeting the influenza-like-illness definition were 0.9%, and no jurisdiction had moderate, high, or very high activity. The page was updated August 21. 2

Moderna's mFLUSIVA remains FDA-approved for adults age 50 and older, with U.S. availability expected during the 2026–27 respiratory-virus season. The company has published no local stocking date, price, or insurance-coverage information on the product page. 3

Two new preclinical papers explored future respiratory vaccines and EBV antibodies. Both improve scientific understanding. Neither changes the vaccine appointment a U.S. family should schedule this week.

The measles number to act on

The CDC measles page, updated August 21 with data current through August 20, lists 2,777 confirmed cases in the United States in 2026. The total includes 2,761 cases reported by 47 U.S. jurisdictions and 16 cases among international visitors. CDC counted 36 outbreaks, defined as three or more related cases, and 94% of all cases were outbreak-associated. 1

Hospitalization was reported for 193 cases, or 7%. The rate was 10% among children younger than 5, 4% among children ages 5–19, and 10% among adults age 20 and older. CDC reported zero deaths in the 2026 count. 1

The vaccination-status breakdown supplies the household task. CDC lists 94% of cases as unvaccinated or having an unknown status, 3% after one MMR dose, and 3% after two doses. CDC says two MMR doses are 97% effective and one dose is 93% effective. 1

Open the record folder before school, camp, college move-in, or international travel. A parent or caregiver who cannot find a reliable record should ask a clinician, pharmacy, or local health department how to document the child's doses. Families planning international travel should ask about the timing of MMR doses because travel guidance can differ by age and itinerary. CDC's current measles page directs families to a healthcare provider for vaccination questions. 1

Flu activity is quiet; fall planning can start

CDC FluView Week 32 covers the seven-day period ending August 15, while the page update appeared August 21. Clinical laboratories reported 154 positive specimens among 21,290 tested, for 0.7% positivity. Nationwide influenza-like illness accounted for 0.9% of outpatient visits. Fifty-three jurisdictions reported minimal influenza-like-illness activity, two had insufficient data, and none reported moderate, high, or very high activity. 2

Public-health laboratories found 15 positive specimens in Week 32. Thirteen were influenza A and two were influenza B. Among the influenza A viruses that were subtyped, nine were H1N1pdm09 and two were H3N2. The table recorded zero H5 specimens that week. Two H1N2 variant infections were reported in the broader update; both were associated with an agricultural fair and neither patient was hospitalized. 2

The report lists 191 preliminary pediatric flu deaths for the 2025–26 season and no pediatric flu deaths reported during Week 32. A seasonal total is a running count; it does not mean that all 191 deaths occurred during the latest reporting week. 2

The quiet activity level gives families time to arrange fall care. The CDC key-facts page currently says September and October are generally good months for most people who need one seasonal dose, with vaccination ideally completed by the end of October. The same page says some children need two doses at least four weeks apart. That page carries a September 2025 update date, so treat it as standing timing guidance rather than a new 2026 schedule announcement. 4

CDC's vaccination-trends page was reported August 21, but its displayed data still cover the 2025–26 respiratory-illness season, with updates ending May 29, 2026. The page contains no 2026–27 flu vaccine-effectiveness estimate. FluView shows which viruses surveillance laboratories detected; it cannot supply a vaccine-effectiveness percentage by itself. 5

What the product pipeline changes

Moderna's mFLUSIVA

Moderna's August 5 product update says the FDA approved mFLUSIVA for adults age 50 and older. For adults age 65 and older, the approval uses the accelerated-approval pathway based on immune responses, with additional research planned to confirm clinical benefit. The product is intended to prevent influenza disease caused by influenza A subtypes and influenza B types represented in the vaccine. 3

The same update expects U.S. availability during the 2026–27 respiratory-virus season. It gives families no pharmacy-by-pharmacy stocking date, price, or insurance-coverage answer. Moderna's approval therefore creates an option for eligible adults to discuss with a clinician or pharmacist; it does not create a reason to leave a fall appointment unplanned. 3

The product page also tells patients to discuss a history of severe vaccine allergy, Guillain–Barré syndrome after a flu vaccine, immune suppression, pregnancy or planned pregnancy, breastfeeding, and fainting with a healthcare provider. Those questions belong to an individual clinical conversation. 3

Pfizer's in-window check

Pfizer's official press-release archive shows no vaccine, influenza, COVID-19, RSV, or other respiratory-vaccine release dated August 17–24. The latest visible August vaccine release is dated August 14 and concerns a Lyme disease candidate's European regulatory filing. The archive therefore supplies no new Pfizer respiratory milestone for this week's U.S. fall-planning decision. 6

Two new papers, translated

An intranasal RSV vaccine in mice

Junqi Xiang and colleagues published Intranasal delivery of a vasoactive intestinal peptide-based circRNA vaccine induces systemic and mucosal immunity against RSV in mice online on August 19 in Molecular Therapy. The PubMed record identifies the paper as an online-ahead-of-print study and gives DOI 10.1016/j.ymthe.2026.08.025. 7

The researchers built a nasal delivery platform around a vasoactive-intestinal-peptide and nucleocapsid fusion protein. In mice, the platform produced serum IgG responses comparable to intramuscular administration, added IgA responses in airway fluid, increased T follicular helper 1 cells, and reduced lung viral burden and inflammation after RSV challenge. The pre-F version protected against both RSV A and RSV B in the mouse model. 7

The evidence stops at the animal model described in the abstract. The record reports no human participants, no clinical safety results, no licensed product, and no U.S. schedule change. For a family, the practical meaning is a clearer picture of where future RSV vaccine research is heading: toward immune responses in the nose and airways. The paper gives families no RSV product to request this week. 7

An EBV antibody in a humanized-mouse model

Ge-Xin Zhao and colleagues published A protective human antibody reveals a quaternary epitope on the Epstein–Barr virus fusion apparatus in Cell Chemical Biology on August 20. The PubMed record gives PMID 42520799 and DOI 10.1016/j.chembiol.2026.06.017. 8

The team described a human monoclonal antibody called 4G12. The antibody recognized a combined surface formed by two EBV proteins, blocked infection of B cells and epithelial cells in laboratory tests, and protected humanized mice after EBV challenge. Cryo-electron microscopy showed the binding site in the virus's fusion machinery. 8

The study is a step toward antibody-based prevention or vaccine design. It is a preclinical result: the abstract reports laboratory experiments and humanized mice, with no human trial, licensed EBV vaccine, or household vaccination recommendation. Families do not need to change a routine vaccine plan because of this paper. 8

Four actions for this week

Check the MMR record. Look for two documented doses before school, camp, college move-in, or international travel. Ask a clinician, pharmacy, or local health department about a missing record.
Put a fall flu visit on the calendar. September and October remain the usual planning window in CDC's current timing guidance. Ask whether a child needs one dose or two, because two doses must be separated by at least four weeks. 4
Ask what is actually available. Adults age 50 and older can ask about mFLUSIVA, an age-appropriate alternative, local stocking, expected cost, and insurance coverage. Product choice also depends on medical history and clinician advice. 3
Keep research and routine care separate. The RSV paper is a mouse study, and the EBV paper is a laboratory and humanized-mouse study. Neither supplies a licensed product or a new U.S. family vaccination instruction. 7 8

This article is general medical information, not a diagnosis or personal vaccination order. A clinician or local health department can answer questions about pregnancy, immune suppression, prior severe allergic reactions, Guillain–Barré syndrome after a flu vaccine, measles exposure, or a vaccine product for a specific age and health history.