A renewed bivalent mRNA booster protects against circulating SARS-CoV-2 variants

recently Weekly reports of morbidity and mortality Researchers published by the U.S. Centers for Disease Control and Prevention (CDC) efficacy of A bivalent coronavirus disease 2019 (COVID-19) vaccine against symptomatic infections caused by several SARS-CoV-2 variants currently circulating throughout the United States

study: Early Estimation of Efficacy of a Bivalent mRNA Booster Dose Vaccine in Prevention of Symptomatic SARS-CoV-2 Infection Caused by Omicron BA.5- and XBB/XBB.1.5-Associated Sublineages in Immunocompetent Adults—For Community Access to Testing Programs Increase, US, Dec 2022-Jan 2023. Image credit: PeopleImages.com – Yuri A / Shutterstock.com

SARS-CoV-2 Omicron subvariant

Since the emergence of a wild-type strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in late 2019, which subsequently led to the COVID-19 pandemic, several SARS-CoV-2 variants have emerged. For example, the SARS-CoV-2 Omicron variant was first detected in Botswana and South Africa in late November 2021.

Since then, the Omicron variant has mutated into several more subvariant strains, the most recent of which include XBB and XBB.1.5. In the United States, the Omicron subvariant XBB was first detected in August 2022. However, by late December 2022, XBB.1.15 had been identified as the predominant circulating strain of SARS-CoV-2, confirming that more than 50% of sequenced samples were positive for this subvariant. rice field.

About research

Several COVID-19 vaccines have been developed and administered to people around the world to mitigate the spread of SARS-CoV-2. Unfortunately, the emergence of mutated SARS-CoV-2 variants has reduced the efficacy of her current COVID-19 vaccine against infection by specific variants. As a result, the researcher updated his original COVID-19 vaccine, which previously targeted his wild-type strain of SARS-CoV-2, to also incorporate the genetic material of the SARS-CoV-2 Omicron variant. Did.

In the current study, the vaccine efficacy (VE) of the updated Pfizer-BioNTech bivalent messenger ribonucleic acid (mRNA) COVID-19 vaccine was tested against Omicron BA.5, XBB, and XBB.1.5 infection in immunocompetent adults. presumed for symptomatic infections caused by BA.5 infection was confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR), reduction or failure of SARS-CoV-2 spike gene (S gene) amplification (SGTF) in XBB/XBB. 1.15 infection was confirmed by the presence of S gene targets (SGTP).

The growing superiority of XBB.1.5

Total 29,175 nucleic acid Amplified test (NAAT) was obtained from adults who had previously received 2 to 4 original doses of the COVID-19 vaccine, of whom 8,358 had a bivalent test 2 to 3 months prior to NAAT. I also received booster shots.

All adults participating in the current study reported one or more COVID-19-like symptoms at the time of NAAT. Taken together, 47% of his study participants were SARS-CoV-2 positive, of which 78% and 22% were infected with BA.5 or XBB/XBB.1.5 subtypes, respectively.

Between 1 December 2022 and 2 January 2023, 33% of samples testing positive for SARS-CoV-2 were of the XBB.1.5 lineage, and more than 50% were XBB/XBB.1.5. bottom. However, when this 30-day period is divided into smaller intervals, the prevalence of XBB.1.5 increases from 33% to 38% between 11 December and 2 January, and from 18 December 2022 to 2023. We found it increased to 43% during January 2nd. .

A bivalent mRNA vaccine protects against symptomatic infection

Approximately 34% of patients who tested negative for SARS-CoV-2 had previously received a bivalent COVID-19 mRNA booster vaccine compared to those who tested positive. Among those who tested positive for SARS-CoV-2, VE of the bivalent vaccine was similar against BA.5 and XBB/XBB.1.15 infection.

Considering age, the bivalent COVID-19 mRNA vaccine was 52% effective against symptomatic infections in adults aged 18 to 49 years and 43% effective in adults aged 50 to 64 years. , was 37% effective in adults over the age of 65. Notably, this VE did not appear to abate 3 months after vaccination in individuals who had previously received his 2, 3, or 4 doses of his original monovalent COVID-19 vaccine.

Conclusion

Current findings support current recommendations by the US CDC to continue offering bivalent immunizations to the general public. As SARS-CoV-2 variants continue to emerge, it is becoming increasingly important for public health officials to monitor VE of her COVID-19 vaccine, both monovalent and bivalent.