# Sanaria breeds hybrid malaria parasite AV27 for a whole-parasite vaccine; 15× liver infectivity in mice

- Published: 2026-11-13 05:12 UTC
- Section: Life & Health › Medicine
- Tags: malaria vaccine, whole-parasite vaccine, PfSPZ-LARC2, Plasmodium falciparum hybrid, AV27 parasite, NF54 strain, liver infectivity, sporozoites, JCI Insight, humanized liver mice
- URL: https://realtech.media/news/rt-3efb210d0dd97e87f8797409_sanaria_breeds_hybrid/

**Researchers crossed two Plasmodium falciparum strains in mosquitoes and obtained a clone that is both manufacturable and better at infecting liver cells. Tested only in cell culture, mosquitoes and mice.**

![Sanaria breeds hybrid malaria parasite AV27 for a whole-parasite vaccine; 15× liver infectivity in mice](https://realtech.media/media/2026/11/8edc3b73e5cad225.jpg)
*NIAID, Wikimedia Commons, CC BY 2.0*

Researchers at Sanaria Inc. and Seattle Children's Research Institute created a hybrid Plasmodium falciparum parasite, AV27, by letting two strains mate inside mosquitoes, according to a release published by EurekAlert on 11 November 2026. The work appeared in JCI Insight. AV27 combines the high sporozoite yield of strain NF54, used in every PfSPZ whole-parasite vaccine so far, with the much higher liver infectivity of the East African isolate MAL31 from Malawi [1]. According to the authors, no genes were added, removed or redesigned [1].

## Why a new strain was needed

NF54 was isolated in 1979 near a Dutch airport from a West African source. It was chosen because it produces more than 100,000 sporozoites per mosquito, which makes manufacturing possible [1]. However, it invades human liver cells up to eight times less efficiently than parasites collected more recently, and its immune targets reflect West Africa of 1979 [1]. PfSPZ vaccines, which use the whole parasite at the sporozoite stage, have produced 100% protection against controlled infection in clinical trials [1].

## Breeding and results

Mosquitoes were fed NF54 together with one of three recent East African parasites: MAL31 and NF165 from Malawi, and HL1209 from a traveller to South Sudan. The sporozoites infected mice with humanized livers, and the offspring were recovered as single clones. The team screened 117 clones, identified 82 hybrids, sequenced 62 genomes and tested the eight most promising [1].

AV27, the offspring of NF54 and MAL31, carries about 50% of its genome from each parent [1]. It reaches the human liver about 15 times more efficiently than NF54. When both were injected into the same mouse, 94% of liver-stage parasites six days later were AV27 and 6% were NF54 [1]. AV27 also formed larger liver-stage parasites [1].

Across eleven production runs in 2023–2025, AV27 yielded a median of 78,179 sporozoites per mosquito, statistically indistinguishable from the NF54 median of 62,388 across twelve runs. MAL31 yielded a median of 3,134 [1]. In predictions across 26 HLA types, AV27 retained about 90% of each parent's CD8+ T cell peptide repertoire: 80.2% of peptides are shared, 9.5% come only from NF54 and 10.3% only from MAL31 [1]. Output and infectivity stayed consistent after 11 and 14 culture passages [1].

## Limits of the study

No humans took part: the work used cell culture, mosquitoes and mice with humanized livers [1]. AV27 is intended for a next-generation PfSPZ-LARC2 candidate, in which the genes PfMei2 and PfLINUP are deleted so the parasite matures in the liver and dies there without entering the bloodstream [1]. The authors state that AV27 is no more virulent, transmissible or drug resistant than either parent [1]. Ashley Vaughan of Seattle Children's noted that whether the higher infectivity gives greater protection in people is a question for a clinical trial [1].

## Sources

1. [EurekAlert](https://www.eurekalert.org/news-releases/1150972)

---

Source: RealTech, realtech.media — https://realtech.media/news/rt-3efb210d0dd97e87f8797409_sanaria_breeds_hybrid/