What to Know About Current COVID-19 Booster Guidance and Vaccine Effectiveness

The U.S. Centers for Disease Control and Prevention advises that everyone 6 months and older receive the updated 2023–2024 COVID-19 vaccine. This step follows Food and Drug Administration authorization and draws on evidence that the shots lower risks of hospitalization and severe illness in higher-risk groups.

Who is eligible for the updated COVID-19 vaccine booster in 2024?

The CDC recommends the 2023–2024 formula for all individuals aged 6 months and older, regardless of prior vaccination history [1]. The guidance replaces earlier formulations and applies to both Pfizer-BioNTech and Moderna products.

The 2023-2024 updated COVID-19 vaccine booster reduces hospitalization by 50% to 70% in adults aged 65 and older, according to IVY Network data.

How effective are the 2023–2024 COVID-19 vaccine boosters, particularly against severe illness?

Real-world data from the IVY Network across 13 states show the updated vaccines reduced COVID-19–associated hospitalization by 50 to 70 percent in adults 65 years and older [2]. Protection against severe outcomes remained higher in this group through early 2024.

Are additional boosters recommended for specific populations?

Adults 65 years and older and people with immunocompromising conditions may receive an extra dose of the updated vaccine [3]. The second dose can be given at least four months after the initial updated shot.

What are the most recent guidelines for children and adolescents regarding COVID-19 boosters?

Children and adolescents from 6 months through 17 years follow the same single-dose recommendation as adults. No additional doses beyond the primary updated series are advised for healthy younger age groups at this time.

What this means

Current U.S. policy centers protection on a single updated dose for the broad population, with targeted extra dosing for older adults and immunocompromised individuals. Effectiveness estimates focus on reduced severe disease rather than prevention of all infections.

Key takeaways

• CDC guidance issued in September 2023 calls for the updated vaccine in everyone 6 months and older.
• IVY Network data through February 2024 indicate 50–70 percent effectiveness against hospitalization in adults 65 and older.
• An additional updated dose remains available for adults 65 and older or those who are immunocompromised.
• Recommendations rest on circulating variant data and may shift with new evidence.

Limitations

Efficacy figures reflect conditions through early 2024 and may change with new variants. Data apply to the United States; access and uptake patterns differ by region and insurance status. International guidance can vary.

Last updated: August 27, 2026