Top 5 Takeaways

  1. Significant Increase in Hospitalizations Among Older Adults: During the Omicron BA.2 variant predominance, hospitalization rates among adults aged ≥65 years showed a threefold increase, highlighting the heightened risk in this age group.
  2. Disproportionate Impact on Unvaccinated Adults: Hospitalization rates were approximately three times higher among unvaccinated adults compared to vaccinated adults, underscoring the effectiveness of vaccination.
  3. Vaccination Status Among Hospitalized Adults: Among hospitalized nonpregnant patients, 44.1% had received a primary vaccination series and at least one booster or additional dose, demonstrating ongoing risk even among some vaccinated individuals.
  4. Importance of Staying Up to Date with Vaccination: The data emphasizes the critical role of COVID-19 vaccinations, including booster doses, in reducing hospitalization risks, especially among older adults and those with underlying medical conditions.
  5. Comprehensive Prevention Strategies Needed: Beyond vaccination, the report advocates for multiple nonpharmaceutical and medical prevention measures to protect high-risk populations.


Original Article Author and Citation

Corresponding Author

Fiona P. Havers,

Suggested Citation

Havers FP, Patel K, Whitaker M, et al. Laboratory-Confirmed COVID-19–Associated Hospitalizations Among Adults During SARS-CoV-2 Omicron BA.2 Variant Predominance — COVID-19–Associated Hospitalization Surveillance Network, 14 States, June 20, 2021–May 31, 2022. MMWR Morb Mortal Wkly Rep 2022;71:1085–1091. DOI:


This MMWR article details an analysis of COVID-19-associated hospitalization rates among adults in the United States during the predominance of the Omicron BA.2 variant, with a specific focus on age and vaccination status. It reveals a significant increase in hospitalizations among older adults and highlights the protective effect of vaccination, including booster doses.


The analysis utilized data from the COVID-19–Associated Hospitalization Surveillance Network (COVID-NET), covering 99 counties across 14 U.S. states, to examine hospitalization rates, vaccination status, and clinical outcomes among adults during different periods of SARS-CoV-2 variant predominance.


The findings underscore the increased hospitalization rates among older adults, particularly during the Omicron BA.2 period, and the continuous protection offered by vaccination. Despite the high vaccination rates, the persistence of hospitalizations among vaccinated individuals indicates the need for additional protective measures.


The report concludes with a call for adults to remain current with COVID-19 vaccinations and for the implementation of comprehensive prevention strategies to mitigate the risk of severe illness, especially among the most vulnerable populations.


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