Q: What are the EG.5 and HV.1 variants?
A: EG.5 and HV.1 are SARS-CoV-2 Omicron variants that currently make up more than half of SARS-CoV-2 cases in the U.S. (CDC November 2023). HV.1 is currently growing in the U.S. and is descended from EG.5. The two variants are genetically similar, and both stem from the XBB Omicron lineage.
Q: Do the EG.5 or HV.1 variants cause more severe disease than other Omicron variants? Are they more transmissible than other variants?
A: At present, it does not appear that EG.5 or HV.1 cause more severe disease than other Omicron variants, nor do they appear to be substantially more transmissible than other Omicron variants. Despite there not being clear genetic changes that are associated with increased transmissibility, it appears that EG.5 has a growth advantage over other Omicron lineages. This may be due primarily to the fact that it is new and replicating in an environment where many individuals do not yet have antibodies capable of neutralizing these variants. Preliminary evidence suggests that EG.5.1 does evade antibody-mediated immune protection to a moderate extent (Faraone, October 2023; Kaku, August 2023).
Q: Do vaccines protect against EG.5 and HV.1 variants?
A: Yes. Updated SARS-CoV-2 vaccines contain antigens against an XBB variant that seems to produce antibodies capable of neutralizing EG.5. Information on vaccine-mediated neutralizing capacity against HV.1 is still being investigated, but it is expected that it will be similar to that of EG.5 due to the variants’ genetic similarity. Despite the capability of updated vaccines to produce antibodies capable of neutralizing these variants, the rapid development of both EG.5 and HV.1 do indicate the need for continued epidemiologic surveillance and COVID-19 vaccine updates.
Q. Do other therapeutics protect against EG.5 and HV.1?
A: Yes. Therapeutics, such as Paxlovid, are still expected to offer protection by reducing the severity of infection from either variant.
Q: Are tests still capable of identifying SARS-CoV-2 infections caused by EG.5 or HV.1?
A: Yes. Although still being gathered, information about the genetic features of these viruses suggests that PCR tests and at-home antigen tests will still be able to identify SARS-CoV-2 infections caused by these variants (Faraone, October 2023; Abbasi, September 2023).