Skip to main content

#KP2 - based monovalent #mRNA #vaccines robustly boost #antibody responses to #SARS-CoV-2

Image
By G.M.

{Excerpt}

In response to the ongoing evolution of SARS-CoV-2, vaccine manufacturers have released updated COVID-19 vaccines annually since 2022. For much of 2024, the global spread was dominated by the JN.1 lineage of viruses,1 which are antigenically quite distant from the XBB.1.5 variant that was used in the previous vaccine booster.2 In August 2024, the US Food and Drug Administration authorised two updated mRNA vaccines (Pfizer–BioNTech and Moderna) based on the spike sequence of KP.2, a subvariant in the JN.1 lineage.3 In the UK and the EU, a KP.2-based mRNA vaccine (BioNTech) was also authorised later in the year.4,5 We have now provided the first indication of the acute boosting effect of updated KP.2 monovalent mRNA vaccines (KP.2 MV) on serum SARS-CoV-2 neutralising antibodies in humans. Since the authorisation of the updated vaccine boosters, SARS-CoV-2 has evolved beyond KP.2, with the subvariant KP.3.1.1 becoming dominant globally and the subvariant XEC now gaining traction rapidly.1 KP.2 contains Arg346Thr, Phe456Leu, and Val1104Leu mutations in spike, in addition to those present in the parental JN.1 (figure A). Both KP.3.1.1 and XEC share Phe456Leu and Val1104Leu mutations found in KP.2, along with Gln493Glu, which is absent in KP.2. In addition, KP.3.1.1 harbors the Ser31del mutation, whereas XEC carries Thr22Asn and Phe59Ser mutations; neither KP.3.1.1 nor XEC possess the Arg346Thr mutation (figure A). The effectiveness of the updated KP.2 MV boosters on neutralising antibodies in human serum against recently dominant subvariants has yet to be reported.

(...)

Source: Lancet Infectious Diseases, https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(25)00058-1/fulltext?rss=yes

_____


Labels:

Comments

Post a Comment

Popular posts from this blog

#USA, APHIS Confirms {Avian #Influenza #H5N1} #D11 #Genotype in Dairy #Cattle in #Nevada

By G.M.
On January 31, 2025, the USDA Animal and Plant Health Inspection Service (APHIS) National Veterinary Services Laboratories (NVSL) confirmed by whole genome sequence the first detection of highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b, genotype D1.1 in dairy cattle .  This confirmation was a result of State tracing and investigation, following an initial detection on silo testing under the USDA’s National Milk Testing Strategy (NMTS) in Nevada.  USDA APHIS continues to work with the Nevada Department of Agriculture by conducting additional on-farm investigation, testing, and gathering additional epidemiological information to better understand this detection and limit further disease spread.  This is the first detection of this virus genotype in dairy cattle (all previous detections in dairy cattle have been HPAI H5N1 clade 2.3.4.4b, genotype B3.13 ).  Genotype D1.1 represents the predominant genotype in the North American flyways this past fall an...
Post a Comment
Read more »

#USA, After #Birdflu Detected in Local #Cat, County #Health Officials Say #Pet Owners Should Contact Veterinarian When Their Pets are Sick

By G.M.
Redwood City — State veterinary and health officials have confirmed a case of H5N1 (bird flu) in a domestic stray cat in San Mateo County.  The infection, which is not related to the recent instance of bird flu in a backyard flock , was found in a stray cat in Half Moon Bay that had been taken in by a family .  When it showed symptoms, they took it to Peninsula Humane Society, whose veterinarians examined it and requested testing. Lab results confirmed H5N1.  It is not known how the cat was infected and it was euthanized due to its condition. Cats may be exposed to bird flu by consuming infected bird , being in environments contaminated with the virus and consuming unpasteurized milk from infected cows or raw food. Inside domestic animals, such as cats and dogs, that go outside are also at risk of infection.​​​​​​​ According to the Centers for Disease Control and Prevention, the risk of cats spreading H5N1 to people is extremely low, though it is possible for cats to spre...
Post a Comment
Read more »

#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 »