# Radboudumc and NYU: prior worm infection protected all mice from lethal H1N1 influenza

- Published: 2026-11-05 16:06 UTC
- Section: Life & Health › Biology & biochemistry
- Tags: H1N1 influenza in mice, Nippostrongylus brasiliensis, worm infection and flu, lung macrophages, immune tolerance, Radboudumc research, NYU Grossman School of Medicine, Kamal Khanna, respiratory virus protection
- URL: https://realtech.media/news/rt-268616273e13f83b937d662b_radboudumc_and_nyu/

**In mice, earlier infection with the parasitic worm Nippostrongylus brasiliensis led to survival of H1N1 influenza, with no change in viral load. Protection depended on lung macrophages.**

![Radboudumc and NYU: prior worm infection protected all mice from lethal H1N1 influenza](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/dc7f5dfc2a2b65f3.avif)
*EOS Wetenschap*

Researchers at NYU Grossman School of Medicine in New York and Radboudumc in Nijmegen found that mice previously infected with a parasitic roundworm survived exposure to the H1N1 influenza virus, EOS Wetenschap reports. [1] The work was led by Kamal Khanna. All the worm-infected mice survived, while all uninfected control mice died five to six days after exposure to the virus. [1]

The study began with an observation from the early covid-19 pandemic: in regions with many parasitic worm infections, the disease after coronavirus infection ran a milder course. The researchers asked whether an earlier worm infection changes how the body responds to a respiratory virus. [1]

## Experiment in mice

The team divided mice into two groups. One group was infected with the roundworm Nippostrongylus brasiliensis, the other was not. Four to six weeks later, all animals were exposed to H1N1, a dangerous influenza virus. [1]

The amount of virus stayed the same in all mice. The infected animals therefore did not clear the virus faster, and the protection had a different mechanism. [1]

## Macrophages and tolerance

The researchers traced the protection to a specialized type of macrophages, immune cells found in the airways and in the nerves of the lungs, which they had identified earlier. According to Radboudumc doctoral researcher Yavor Yardanov, these cells store the experience of a previous worm infection in a kind of memory and then produce a tolerant immune response to the next infection. The response is much less intense, which, he said, means less harmful inflammation, faster recovery of lung tissue and better preserved breathing. [1]

Follow-up experiments supported this. When the macrophages were removed, the protection disappeared. When the cells were transferred to other animals, the protection was restored. The researchers also reproduced the same protective effect with two purified signaling molecules, without using the worm itself, and found similar macrophages in human lungs. [1]

The authors say the findings could be a step toward a different type of therapy that targets not the virus but the ability of the lungs to tolerate infection. Musa Mhlanga, professor at Radboudumc, said that such an approach does not depend on knowing which virus is circulating, and that it could particularly help people with underlying conditions, who are most vulnerable to severe lung damage. [1]

## Sources

1. [EOS Wetenschap](https://www.eoswetenschap.eu/themas/gezondheid/worminfectie-beschermt-muizen-tegen-dodelijke-griep)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-268616273e13f83b937d662b_radboudumc_and_nyu/