H3N2 News and Research

RSS

Influenza A virus subtype H3N2 (also H3N2) is a subtype of viruses that cause influenza (flu). H3N2 viruses can infect birds and mammals. In birds, humans, and pigs, the virus has mutated into many strains. H3N2 is increasingly abundant in seasonal influenza, which kills an estimated 36,000 people in the United States each year.

Children remain more vulnerable to influenza despite protective antibody levels

Researchers analyzing 1,518 South African household participants found that higher pre-season antibody titers were associated with lower infection risk for three of four influenza viruses studied. Children remained more susceptible after accounting for measured exposure and antibody titers, while younger children shed viral RNA longer than older adults.

3 Aug 2026

ddPCR and NGS for viral surveillance in antiviral drug development

hVIVO explains how ddPCR and NGS support viral surveillance in antiviral trials, from detection and quantification to resistance sequencing.

From hVIVO 20 Jul 2026

New discovery provides insights into how seasonal influenza viruses infect people

Scientists investigating how influenza viruses replicate within cells "accidentally" discovered that different flu viruses use distinct strategies to infiltrate cells in the first place.

2 Jun 2026

Why H2N2 flu is back on the pandemic preparedness radar

A historical review in Vaccine warns that global H2N2 immunity has sharply declined since the 1957 Asian influenza pandemic, leaving most people without H2-specific protection if the virus re-emerges. The authors highlight animal reservoirs, waning birth-cohort immunity, and modern H2 vaccine platforms as key priorities for pandemic preparedness.

28 Apr 2026

Childhood flu infection leaves lasting immune imprint

A study reveals how childhood flu infections impact long-term mortality risk, highlighting implications for vaccination and future outbreak management.

17 Apr 2026

Flu vaccines protect children well across Europe, but H3N2 remains harder to stop

Influenza vaccination provided strong real-world protection for children in European primary care across two seasons, with overall vaccine effectiveness of 68% in 2022–2023 and 71% in 2023–2024. Protection was highest against influenza B and H1N1, while H3N2 showed lower and more variable effectiveness, supporting the need for higher uptake and continued monitoring.

8 Apr 2026

Prior flu exposure may weaken the immune response to other strains

Prior exposure to one strain of influenza virus may weaken children's ability to mount an effective antibody response against their subsequent exposure to a different flu strain, according to a study led by Weill Cornell Medicine investigators.

11 Mar 2026

Advancing influenza vaccine development: Sino Biological launches antigens for the 2026-2027 Northern Hemisphere influenza vaccine strains

The World Health Organization (WHO) has announced its recommendations for the 2026–2027 Northern Hemisphere influenza vaccine composition.

From Sino Biological Inc. 4 Mar 2026

WHO updates 2026-2027 flu vaccine composition amidst viral evolution

The World Health Organization (WHO) today announced recommendations for the viral composition of influenza (or "flu") vaccines for the 2026-2027 northern hemisphere influenza season.

27 Feb 2026

Poor dietary iron weakens lung memory T cells after flu infection

Dietary iron deficiency in mice alters lung T cell activation during influenza infection and leads to memory T cells that are present in normal or increased numbers but have impaired antiviral cytokine responses. These functional deficits are most pronounced in lung CD8-positive memory T cells and persist even under optimal recall conditions.

8 Dec 2025

Age and flu vaccine type influence immune activation

New research comparing four different flu vaccines found that the ability of the vaccines to activate cells of the immune system that help to protect against infection varied greatly depending on the vaccine type and age of the patient.

12 Nov 2025

CRISPR therapy shows promise against influenza in human lung chips

The Influenza A virus (IAV) has been the cause of six major flu pandemics, responsible for 50 to 100 million deaths globally.

15 Oct 2025

Taste-based flu test that detects infection within minutes

Researchers examine the effectiveness of a novel taste-based sensor for the early detection of influenza infection.

8 Oct 2025

WHO issues guidance for 2026 flu vaccine formulation in the southern hemisphere

The World Health Organization (WHO) today announced its recommendations for the viral composition of influenza vaccines for use in the 2026 influenza season in the southern hemisphere.

26 Sep 2025

AI model predicts flu vaccine strains more accurately than WHO

AI-based models like VaxSeer outperform traditional methods in flu vaccine strain selection, enhancing effectiveness and addressing global influenza challenges.

2 Sep 2025

It’s almost flu season. Should you still get a shot, and will insurance cover it?

For parents of school-aged children, the fall to-do list can seem ever-growing. Buy school supplies. Fill out endless school forms.

18 Aug 2025

Rising human adaptive potential seen in 2.3.4.4b clade of H5N1

In recent years, there has been growing concern over the H5N1 influenza virus. It was first identified in birds three decades ago and has now gradually found its way to humans.

12 Aug 2025

Study finds past H1N1 exposure shields animals from deadly H5N1

Preexisting immunity to the 2009 H1N1 influenza virus provided near-complete protection against severe H5N1 disease and transmission in ferrets, even after high-dose exposure. In contrast, H3N2 immunity alone offered only partial, inconsistent protection.

28 Jul 2025

Individual immune variation shapes the evolution of influenza strains

A new study has shown that person-to-person variation in antibody immunity plays a key role in shaping which influenza (flu) strains dominate in a population.

3 Jun 2025

What makes H5N1 a pandemic risk and how can we stop it?

A new PEARLS article in PLoS Pathogens reviews the rapid evolution and pandemic potential of emerging influenza A viruses, with a focus on H5N1. It highlights scientific advances and future strategies to outpace the virus, from next-generation vaccines to AI-driven antiviral discovery.

19 May 2025