Skip to main content

#Detection of low pre-existing #humoral #immunity against #influenza virus #H5N1 clade 2.3.4.4b in unexposed individuals

Image
By G.M.

Abstract

The repeated spill-over of Influenza A virus H5N1 clade 2.3.4.4b from cattle to humans highlights the risk of a human H5N1 pandemic. Given the impact of pre-existing immunity on the course and severity of viral infections, we assessed in detail the humoral immunity against the H5N1 A/Texas/37/2024 isolate in H5N1-naive individuals. To this end, we performed complementary binding and neutralization assays on 66 subjects and ranked activities among a panel of 76 influenza A virus isolates. We detected low but distinct cross-neutralizing titers against A/Texas/37/2024 with a 3.9 to 15.6-fold reduction compared to selected H1N1 or H3N2 strains. Moreover, by cloning and evaluating 136 monoclonal antibodies from single memory B cells, we identified potent A/Texas/37/2024-neutralizing monoclonal antibodies in five out of six investigated individuals. These antibodies predominantly utilize VH1-69 gene segments, cross-neutralize H1, and compete with antibodies targeting the HA stem. Our findings demonstrate partial pre-existing humoral immunity to A/Texas/37/2024 in H5N1-naive individuals.

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2025.01.22.634277v1

_____

Labels:

Comments

Post a Comment

Popular posts from this blog

#USA, Novel #Influenza A #H5N1 Virus: One Pediatric Case in #California {FluView}

By G.M.
 {Excerpt} One confirmed human infection with influenza A(H5) virus was reported to CDC this week. To date, human-to-human transmission of influenza A(H5) virus has not been identified in the United States. This case was reported by the California Department of Public Health and occurred in a child less than 18 years old with no known contact with influenza A(H5N1) virus-infected animals or humans . The investigation into the source of infection for this case is ongoing , and no human-to-human transmission has been identified. A specimen from the individual was tested at a public health laboratory using the CDC influenza A(H5) assay before being sent to CDC for further testing. The specimen was positive for influenza A(H5) virus using diagnostic RT-PCR at CDC. Additional analysis including genetic sequencing is underway. In response to this detection, additional case investigation and contact monitoring are being conducted by public health officials in California. There have now be...
Post a Comment
Read more »

#USA, Two more #human cases of #H5N1 #birdflu reported in #California

By G.M.
Two cases of bird flu have been reported in San Joaquin County, California, local health officials said. According to a press release issued Friday and reported by the Sacramento Bee , health officials with San Joaquin County Public Health Services said both cases were farm workers who were exposed to infected animals . Both people are showing mild symptoms and are recovering, officials said, adding that there are 34 total confirmed cases across California. In a warning posted on Facebook, health officials said bird flu was “spreading in several farms such as poultry and cattle” and urged residents to take precautions to prevent the spread of the disease. Precautions include the use of protective equipment when handling poultry, dairy cattle or other animals that may be infected, and when handling raw and unpasteurized milk. (...) There are currently 60 confirmed cases of bird flu in the country . While most of the cases are in California , other states with confirmed cases include Col...
Post a Comment
Read more »

#PuertoRico - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

By G.M.
Highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b was confirmed on one poultry premises in Culebra Municipality, Puerto Rico . This is the first confirmed case of HPAI in poultry from Puerto Rico. Full genotyping confirms the virus as a reassortant of the A3 genotype with North American wild bird lineage viruses ( AM PB2, PA, NP ). Comparisons of the virus to other recent detections from wild birds and North America reports are in progress. The USDA Animal and Plant Health Inspection Service (APHIS), in conjunction with State Animal Health and Wildlife Officials, are conducting comprehensive epidemiological investigations and enhanced surveillance in response to the HPAI H5N1 related events. Source: WOAH,  https://wahis.woah.org/#/in-review/6185 _____
Post a Comment
Read more »