Top 5 Takeaways:

1. Bivalent mRNA Vaccine Effectiveness: The study found that bivalent mRNA vaccines are effective in preventing COVID-19–associated emergency department/urgent care encounters and hospitalizations among immunocompetent adults.
2. Comparative Analysis: The vaccine’s effectiveness was compared with both unvaccinated individuals and those who had only received monovalent mRNA vaccines.
3. Protection Rates: The effectiveness against COVID-19–associated ED/UC encounters was 56% compared to no vaccination, and varied from 31% to 50% compared to monovalent vaccination, depending on the time since the last dose.
4. Hospitalization Prevention: For preventing hospitalizations, the effectiveness was 57% compared to no vaccination, and varied from 38% to 45% compared to monovalent vaccination.
5. Recommendations: The study supports the recommendation for all eligible individuals to stay up-to-date with COVID-19 vaccinations, including receiving a bivalent booster dose.

Original Article Author and Citation

Corresponding Author

Mark W. Tenforde, media@cdc.gov.

Suggested Citation

Tenforde MW, Weber ZA, Natarajan K, et al. Early Estimates of Bivalent mRNA Vaccine Effectiveness in Preventing COVID-19–Associated Emergency Department or Urgent Care Encounters and Hospitalizations Among Immunocompetent Adults — VISION Network, Nine States, September–November 2022. MMWR Morb Mortal Wkly Rep 2022;71:1616–1624. DOI: http://dx.doi.org/10.15585/mmwr.mm715152e1.

Summary

This MMWR article presents an evaluation of the effectiveness of bivalent mRNA COVID-19 vaccines in preventing medically attended COVID-19 cases among immunocompetent adults. It covers a period when the Omicron BA.5 sublineage was predominant in the U.S.

Methods

The study utilized data from the VISION Network, analyzing emergency department/urgent care encounters and hospitalizations for COVID-19–like illness. Vaccine effectiveness was assessed among adults who received a bivalent booster dose compared to those unvaccinated or vaccinated with monovalent mRNA vaccines only.

Discussion

The study found that bivalent vaccines offered significant protection against COVID-19 compared to no vaccination and additional protection compared to monovalent vaccination. The research highlights the importance of staying current with COVID-19 vaccinations, including the bivalent booster.

Conclusion

The findings underscore the effectiveness of bivalent mRNA vaccines in reducing COVID-19–associated medical encounters among adults. They support ongoing vaccination efforts, especially with the bivalent booster, and suggest the need for continued public health measures to combat respiratory illnesses.

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