COVID vaccines effectiveness in adults — new CDC report – GWC Mag

A new study from the CDC examined the effectiveness of the COVID-19 vaccines and showed that provided approximately 54% increased protection against symptomatic SARS-CoV-2 infection compared with no receipt of updated vaccine. The vaccines also provided protection against the new JN.1 variant.

I want to quickly review the data from the CDC and summarize what it means for the vaccine.

COVID-19 vaccines effectiveness report

In a paper published on 1 February 2024 in the CDC’s Morbidity and Mortality Weekly Report, Ruth Link-Gelles, Ph.D., of the CDC’s National Center for Immunization and Respiratory Diseases, and colleagues examined 9,222 NAAT (nucleic acid amplification tests, a type of test for COVID-19) COVID test results over the study period among people with COVID-like symptoms. Most people tested were women (61%), about 40% were white, 30% were Hispanic or Latino, and 16% were Black or African American.

Here are the key results:

• Overall, vaccine effectiveness against symptomatic COVID was 57% for people ages 18 to 49 years and 46% for people ages 50 and older.
• Vaccine effectiveness was 49% for tests indicating infection with JN.1 lineages, and 60% for tests indicating infection with non-JN.1 lineages.
• Vaccine effectiveness was 58% among those who received testing 7 to 59 days after receiving the updated vaccine, and 49% among those who received testing 60 to 119 days after receipt.
• Only 12% of all people tested reported that they had received an updated vaccine dose, and over 26% had never received any COVID vaccine.

The authors concluded that:

All persons aged ≥6 months should receive updated 2023–2024 COVID-19 vaccine. CDC will continue monitoring COVID-19 VE, including against severe disease and for expected waning.

Summary

I think some people reading this will say “The vaccine is like a coin flip it only works 50% of the time.” What it means is that if you get the vaccine you have at least a 50% lower chance of contracting a severe disease. Moreover, the updated vaccines reduce the risk of waning immunity which happens with many vaccines as the virus mutates.

The vaccine works, and people should get it.

Citations

• Link-Gelles R, Ciesla AA, Mak J, Miller JD, Silk BJ, Lambrou AS, Paden CR, Shirk P, Britton A, Smith ZR, Fleming-Dutra KE. Early Estimates of Updated 2023-2024 (Monovalent XBB.1.5) COVID-19 Vaccine Effectiveness Against Symptomatic SARS-CoV-2 Infection Attributable to Co-Circulating Omicron Variants Among Immunocompetent Adults – Increasing Community Access to Testing Program, United States, September 2023-January 2024. MMWR Morb Mortal Wkly Rep. 2024 Feb 1;73(4):77-83. doi: 10.15585/mmwr.mm7304a2. PMID: 38300853.