The recent data from the CDC’s IVY and VISION networks have shed light on the protection provided by the newly updated COVID vaccines against severe virus-related outcomes in immunocompetent adults. According to Jennifer DeCuir, MD, PhD, and colleagues, the vaccine effectiveness (VE) against COVID-related emergency department or urgent care encounters ranged from 47% to 52%, and the protection against hospitalizations associated with the coronavirus varied from 43% to 52%. These results emphasize the importance of updated COVID-19 vaccination, including for individuals who have previously received different versions of the vaccine or those who have never been vaccinated, regardless of their infection history.
Despite the authorization by the FDA and the recommendation by the CDC’s Advisory Committee on Immunization Practices for the 2023-2024 COVID-19 vaccines for both adults and children ages 6 months and older, the uptake of the updated shots has been comparatively low. Only 22% of U.S. adults, including 42% of adults aged 65 and older, have received the latest vaccines. Given the low uptake rate, there is a need for increased awareness and education regarding the importance and efficacy of the updated vaccines in preventing severe COVID-19 outcomes.
The study incorporated data from 369 emergency departments, urgent care clinics, and 229 hospitals across eight states in the VISION network, as well as 26 hospitals in 20 states in the IVY network. The analysis included 128,825 adults with a median age of 52 years, of which 61% were female and 64% were white. Among these adults, the vaccine effectiveness against emergency department and urgent care visits was found to be higher for individuals who received the vaccine 7-59 days earlier compared to those who received it 60-119 days earlier.
Interestingly, the analysis also revealed variations in vaccine effectiveness based on age groups. Individuals aged 18-64 exhibited higher protection against emergency department and urgent care visits compared to those aged 65 years and older. Similarly, the vaccine effectiveness against COVID-related hospitalizations was higher among patients aged 65 and older compared to adults under 65 years in both the VISION and IVY subsets. These findings underscore the importance of age-specific considerations when assessing the effectiveness of updated COVID vaccines in preventing severe outcomes.
Despite the differences in populations, methodologies, and outcomes, the estimates of the effectiveness of the updated COVID-19 vaccines remained consistent across the VISION and IVY analyses. The alignment in results indicates the reliability and efficacy of the updated vaccines in protecting against serious virus-related outcomes. By early January, the JN.1 lineage accounted for a significant portion of circulating lineages in the U.S., emphasizing the need for continued monitoring and assessment of vaccine effectiveness against emerging variants.
The data from the CDC’s IVY and VISION networks highlight the crucial role of updated COVID vaccines in providing protection against severe outcomes. The findings underscore the need for increased vaccination rates, particularly in high-risk populations, to mitigate the impact of COVID-19 and prevent serious illness and hospitalizations. Continued research and surveillance are essential to track the effectiveness of vaccines against evolving variants and to inform public health strategies for controlling the spread of the virus.