Fall 2025 COVID booster update: FDA endorses JN.1-based vaccine as dominant LP.8.1 strain spreads

The U.S. Food and Drug Administration announced that the upcoming 2025–2026 COVID-19 booster campaign will target the JN.1 lineage, specifically the LP.8.1 subvariant, following a unanimous recommendation from its Vaccines and Related Biological Products Advisory Committee. The announcement comes as LP.8.1 has rapidly become the dominant COVID-19 strain in the United States, accounting for over 70% of new cases reported nationwide, according to CDC surveillance.

The decision was made public late on last Wednesday following the FDA’s advisory panel session, which reviewed the latest variant prevalence data and immunological research provided by U.S. and international health agencies. Moderna, Pfizer-BioNTech, and Novavax have been instructed to begin manufacturing and submitting formulations based on this updated target.

Why Was the JN.1 Lineage Selected for the New Booster?

The JN.1 variant and its sublineages, including LP.8.1, have steadily displaced previous dominant strains such as XBB.1.5 and BA.2.86 throughout early 2025. Public health officials from the Centers for Disease Control and Prevention (CDC) noted that JN.1 demonstrates superior transmissibility and mild immune escape properties, allowing it to infect even vaccinated individuals, though most cases remain mild.

The LP.8.1 subvariant, which carries additional spike protein mutations, now represents a majority of sequenced cases in regions like California, New York, and Texas. According to virologists consulted by the FDA, the new vaccine targeting LP.8.1 is expected to boost neutralizing antibody levels against the most widely circulating version of SARS-CoV-2 this fall and winter. This approach mirrors previous seasonal influenza updates, in which vaccine composition is aligned with the most prevalent global strains.

How Effective Will the Updated Booster Be?

During the advisory committee meeting, all three vaccine manufacturers presented preliminary data suggesting that the LP.8.1-based booster would significantly improve immune responses compared to the current monovalent JN.1 formulation. Cross-neutralization studies shared by Pfizer and Moderna indicate the updated vaccine maintains strong efficacy against NB.1.8.1, another emerging subvariant that has gained global attention for its rapid spread in China, India, and the United States.

Although final real-world effectiveness data will become available only after rollout, immunogenicity studies submitted to the FDA show that the new formulation leads to a two- to three-fold increase in neutralizing antibodies in older adults compared to boosters formulated against earlier strains. The FDA emphasized that existing vaccines still provide protection against severe illness but that updated formulations will better align with current viral evolution.

Who Will Be Eligible for the Fall 2025 COVID Booster?

Eligibility criteria for the fall 2025 COVID-19 booster are undergoing revision. As of the latest policy direction, the FDA is prioritizing administration to adults over 65, individuals with high-risk conditions, healthcare workers, and residents in long-term care facilities. The agency has indicated that broader population groups, including adults under 65 and children, may be recommended for vaccination based on further evidence from upcoming clinical trials.

This shift reflects a new FDA strategy that seeks to focus limited resources on populations with higher mortality and hospitalization risk. The CDC is expected to finalize distribution guidance in coordination with state health departments by mid-June 2025.

When Will the Booster Be Available to the Public?

Pfizer, Moderna, and Novavax are expected to begin shipments of the LP.8.1-based booster in August 2025, pending final regulatory approval. Moderna has indicated it is targeting a mid-to-late August availability window, while Pfizer has stated it will be ready to begin mass production as early as July. Novavax’s updated protein-based vaccine is also in advanced stages of production and is anticipated to roll out shortly thereafter.

The U.S. government, which no longer funds large-scale COVID-19 vaccination procurement, is expected to rely on commercial distribution through pharmacies, clinics, and health departments. The CDC and state-level immunization programs will coordinate outreach efforts for vulnerable communities through Medicare, Medicaid, and Federally Qualified Health Centers (FQHCs).

What’s the Global Context Around the Fall Booster Strategy?

Globally, several countries are also updating their vaccination strategies in line with the emergence of JN.1 and LP.8.1. The European Medicines Agency (EMA) is reviewing similar submissions from vaccine manufacturers, while Canada and the U.K. have expressed interest in aligning their fall booster programs with the FDA’s recommendations.

In India, the Ministry of Health has begun evaluating LP.8.1-based formulations submitted by Bharat Biotech and Serum Institute of India. Meanwhile, Singapore and Australia are seeing increased case numbers from both LP.8.1 and NB.1.8.1 subvariants, prompting local health ministries to consider earlier fall vaccination schedules.

WHO officials, while supportive of updated booster strategies, have urged equity in access as manufacturers scale up production. Global distribution initiatives under COVAX are reportedly in talks with Pfizer and Moderna for 2025–2026 procurement commitments, particularly for low-income nations still facing logistical and financing barriers.

What Precautions Are Being Recommended Ahead of Fall?

U.S. public health officials are urging vulnerable groups not to wait for the updated fall booster to take protective steps. According to guidance from the CDC, older adults and those with underlying conditions should ensure their current booster is up to date while awaiting the fall formulation. If more than six months have elapsed since a previous dose, an interim booster may be considered, particularly in areas experiencing rising NB.1.8.1 cases.

State and local health departments are also expected to begin public outreach campaigns by July, emphasizing the importance of early fall vaccination to preempt a potential surge in respiratory illnesses, including flu, RSV, and COVID-19. Hospital systems are being advised to prepare for dual-seasonal pressures.

How Does This Affect the U.S. COVID-19 Outlook for Late 2025?

While the public health emergency officially ended in May 2023, the persistent emergence of new subvariants like NB.1.8.1 and the growth of LP.8.1 reinforce the reality that COVID-19 will remain a seasonal respiratory pathogen requiring annual mitigation. With vaccination fatigue contributing to lower booster uptake, particularly among adults under 50, public health agencies are working to reframe COVID vaccination as a routine preventive health measure, similar to the annual flu shot.

By the end of 2024, only 22% of eligible U.S. adults had received the previous JN.1-based monovalent booster. CDC officials are aiming to raise that figure significantly for fall 2025 through improved public messaging, simplified vaccination access, and community-level partnerships.