Chen S, Quan K, Wang H, Li S, Xue J, Qin T, Chu D,. A Live Attenuated H9N2 Avian Influenza Vaccine Prevents the Viral Reassortment by Exchanging the HA and NS1 Packaging Signals. Front Microbiol. 2021 Feb 4;11:613437
The H9N2 avian influenza virus is not only an important zoonotic pathogen, it can also easily recombine with other subtypes to generate novel reassortments, such as the H7N9 virus. Although H9N2 live attenuated vaccines can provide good multiple immunities, including humoral, cellular, and mucosal immunity, the risk of reassortment between the vaccine strain and wild-type virus is still a concern. Here, we successfully rescued an H9N2 live attenuated strain [rTX-NS1-128 (mut)] that can interdict reassortment, which was developed by exchanging the mutual packaging signals of HA and truncated NS1 genes and confirmed by RT-PCR and sequencing. The dynamic growth results showed that rTX-NS1-128 (mut) replication ability in chick embryos was not significantly affected by our construction strategy compared to the parent virus rTX strain. Moreover, rTX-NS1-128 (mut) had good genetic stability after 15 generations and possessed low pathogenicity and no contact transmission characteristics in chickens. Furthermore, chickens were intranasally immunized by rTX-NS1-128 (mut) with a single dose, and the results showed that the hemagglutination inhibition (HI) titers peaked at 3 weeks after vaccination and lasted at least until 11 weeks. The cellular immunity (IL-6 and IL-12) and mucosal immunity (IgA and IgG) in the nasal and trachea samples were significantly increased compared to inactivated rTX. Recombinant virus provided a good cross-protection against homologous TX strain (100%) and heterologous F98 strain (80%) challenge. Collectively, these data indicated that rTX-NS1-128(mut) lost the ability for independent reassortment of HA and NS1-128 and will be expected to be used as a potential live attenuated vaccine against H9N2 subtype avian influenza.
See Also:
Latest articles in those days:
- High-throughput pseudovirus neutralisation maps the antigenic landscape of influenza A/H1N1 viruses 19 hours ago
- Timely vaccine strain selection and genomic surveillance improve evolutionary forecast accuracy of seasonal influenza A/H3N2 19 hours ago
- Evaluation of a Novel Data Source for National Influenza Surveillance: Influenza Hospitalization Data in the National Healthcare Safety Network, United States, September 2021-April 2024 19 hours ago
- Scenarios for pre-pandemic zoonotic influenza preparedness and response 19 hours ago
- Stability of Avian Influenza A(H5N1) Virus in Milk from Infected Cows and Virus-Spiked Milk 2 days ago
[Go Top] [Close Window]


