Medical Advisory Board: Dr. Ram Dandillaya, Clinical Chief, Cardiology, Cedars-Sinai; Dr. Antonio J. Forte, Faculty, Mayo Clinic; Dr. John J. Lee, Faculty, Harvard Medical School; Dr. Daniel Kahneman, Nobel Prize Laureate. OpenEvidence is a Mayo Clinic Platform Accelerate Company.
The effectiveness of current COVID-19 vaccines against the XBB.1.16 variant is not definitively known, as specific studies on this variant are limited. However, some insights can be drawn from studies on related variants.
The BNT162b2 bivalent mRNA vaccine booster has been shown to fail to protect against the XBB.1 variant in patients with cancer.[1] The XBB.1.16 variant shares a genetic makeup similar to the XBB.1.5 variant, suggesting that the vaccine's effectiveness might be similarly limited.[2]
However, data from the Increasing Community Access to Testing (ICATT) program in the United States showed that the bivalent mRNA COVID-19 vaccines provided some protection against symptomatic infection caused by XBB/XBB.1.5-related sublineages among immunocompetent adults, with a vaccine effectiveness of 48%.[3]
The Advisory Committee on Immunization Practices (ACIP) has noted that the effectiveness of monovalent COVID-19 vaccines has declined over time due to differences between the virus for which the initial vaccines were designed and currently circulating variants.[4] The ACIP recommends that all persons should stay up to date with recommended COVID-19 vaccines, including receiving a bivalent booster dose when they are eligible.[4]
Further research is needed to determine the specific effectiveness of current COVID-19 vaccines against the XBB.1.16 variant.


1.Ehmsen S, Pedersen RM, Bang LL, et al. BQ.1.1, XBB.1, and XBB.1.5 Neutralization After Bivalent mRNA COVID-19 Booster in Patients With Cancer. Cancer Cell. 2023;41(4):649-650. doi:10.1016/j.ccell.2023.02.003.
2.John OO, Olabode ON, Lucero-Prisno Iii DE, Adebimpe OT, Singh A. XBB.1.16 Omicron Subvariant Rise to a Variant of Interest: Implications for Global Alertness and Preparedness. Journal of Taibah University Medical Sciences. 2023;18(6):1285-1287. doi:10.1016/j.jtumed.2023.05.013.
4.Rosenblum HG, Wallace M, Godfrey M, et al. Interim Recommendations From the Advisory Committee on Immunization Practices for the Use of Bivalent Booster Doses of COVID-19 Vaccines - United States, October 2022. MMWR. Morbidity and Mortality Weekly Report. 2022;71(45):1436-1441. doi:10.15585/mmwr.mm7145a2.