The XBB/XBB.1.5 subvariant of SARS-CoV-2 exhibits increased vaccine susceptibility

*Important Notices: medrex sib We publish a non-peer-reviewed, preliminary scientific report and should not be taken as conclusive, to guide clinical practice/health-related actions, or to be treated as established information.

A team of US-based scientists recently investigated the susceptibility of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron subvariant XBB/XBB.1.5 to vaccine- and infection-induced immune responses Did.

This research is currently medrex sib*Preprint server shows that Omicron subvariant XBB/XBB.1.5 is more susceptible to vaccine-induced immunity than other co-circulating SARS-CoV-2 variants.

study: Increased vaccine susceptibility of emerging SARS-CoV-2 variantst. Image credit: NIAID

Background

Virus evolution is primarily driven by the host’s immune response, which is a major source of selective pressure. With the gradual induction of anti-SARS-CoV-2 immunity at the population level through vaccination and infection, newly emerging virus variants are often under selective pressure, leading to the emergence of virus variants with escape mutations and It improves immune fitness.

SARS-CoV-2 omicron is a recently emerging variant of concern (VOC) that has a significantly higher ability to evade pre-existing immunity compared to other SARS-CoV-2 VOCs. Among the various Omicron subvariants, XBB/XBB.1.5 showed higher immune evasion capacity and by late January became the predominant circulating variant in the United States. 2023.

In the current study, scientists wondered whether Omicron subvariant XBB/XBB.1.5 is more susceptible or resistant than Omicron BA.5-related subvariants to host immune responses acquired by infection or vaccination. was investigated.

research design

The study was conducted on a total of 31,739 individuals who tested positive for SARS-CoV-2 between December 2022 and February 2023. A spike gene detection and spike gene target failure (SGTF) approach was used to distinguish between XBB/XBB.1.5. and other BA.2-related subvariants from BA.4 and BA.5-related subvariants.

Of all enrolled cases, 9,869 were confirmed with XBB/XBB.1.5 infection and 21,870 with other omicron subvariants. Both XBB/XBB.1.5-infected and XBB/XBB.1.5-uninfected cases showed comparable demographic characteristics, comorbidities, and frequency of healthcare utilization.

important observation

Study analysis reveals that cases with XBB/XBB.1.5 infection received fewer doses of coronavirus disease 2019 (COVID-19) vaccine compared to cases infected with other cocirculating subvariants. I was. Furthermore, we showed that XBB/XBB.1.5-infected cases were more likely to have been previously infected with SARS-CoV-2, regardless of their vaccination status.

These observations indicate that omicron XBB/XBB.1.5 is more resistant to infection-induced immunity than other cocirculating omicron subvariants and pleomicron variants. However, this omicron subvariant is relatively sensitive to vaccine-induced immune responses. The susceptibility of XBB/XBB.1.5 to vaccine-induced immunity does not appear to vary with vaccination timing or with the number of doses of monovalent or bivalent vaccines.

Regarding disease severity, COVID-19 vaccination was found to provide greater protection against hospitalization in XBB/XBB.1.5-infected cases than in non-XBB/XBB.1.5-infected cases. However, no significant association was observed between previous infection with XBB/XBB.1.5 or non-XBB/XBB.1.5 subvariants and the risk of hospitalization.

These observations further emphasize the importance of COVID-19 vaccination in preventing XBB/XBB.1.5 infection and disease progression.

Significance of research

This study reveals that the Omicron subvariant XBB/XBB.1.5 is more susceptible to vaccine-induced immunity than other cocirculating subvariants. Additionally, COVID-19 vaccination provides enhanced protection against hospitalization for cases infected with XBB/XBB.1.5.

We show that XBB/XBB.1.5, despite being susceptible to vaccine-induced immunity, has a higher ability to evade infection-induced immunity than other cocirculating omicron subvariants and pleomicron variants. Given this finding, scientists suggest that continued monitoring of vaccine- and infection-induced changes in defense is necessary to inform the response to emerging SARS-CoV-2 variants. I’m here.

*Important Notices: medrex sib We publish a non-peer-reviewed, preliminary scientific report and should not be taken as conclusive, to guide clinical practice/health-related actions, or to be treated as established information.