WHO Updates COVID-19 Vaccine Recommendations: The Shift to LP.8.1 Antigen

As SARS-CoV-2 continues to evolve, the vaccines used to combat it must evolve too. To ensure that our immune systems recognize and fight the most current versions of the virus, the World Health Organization (WHO) periodically reviews and updates the recommended antigen composition for COVID-19 vaccines.

In its most recent guidance, the WHO has shifted its primary recommendation to target a new variant. This update is critical for maintaining high levels of protection across global populations as the virus undergoes genetic and antigenic changes.

The Latest Recommendation: Monovalent LP.8.1

Following a decision-making meeting in December 2025, the WHO Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC) advised vaccine manufacturers that monovalent LP.8.1 is now the recommended vaccine antigen.

The primary goal of updating the antigen composition is to enhance vaccine-induced immune responses against the specific SARS-CoV-2 variants currently circulating. By updating the “blueprint” the vaccine provides to the immune system, the WHO aims to ensure that the antibodies produced are as effective as possible against the most prevalent strains.

Alternative Options and Availability

While LP.8.1 is the current recommendation, the WHO emphasizes that access to the newest version should not be a barrier to protection. The following guidelines apply to alternative vaccines:

• Suitable Alternatives: Antigens from the JN.1 lineage, specifically JN.1 or KP.2, remain suitable alternatives.
• No Delay in Vaccination: The WHO explicitly advises that vaccination should not be delayed while waiting for vaccines with the LP.8.1 composition to become available.
• Broad-Spectrum Approaches: The WHO also considers other vaccine approaches that demonstrate robust neutralizing antibody responses or efficacy against currently circulating variants.

Evolution of Recommendations

This update follows a previous recommendation from May 2025, during which TAG-CO-VAC suggested that monovalent JN.1 or KP.2 were appropriate antigens, while monovalent LP.8.1 was already identified as a suitable alternative. The December 2025 update reflects the ongoing need to track the virus’s genetic drift to keep vaccines effective.

Why Antigen Composition Matters

To understand these updates, it’s helpful to understand what an “antigen” is in the context of a vaccine. An antigen is a molecular structure—usually a protein from the surface of the virus—that the vaccine teaches your immune system to recognize.

When the virus mutates, the shape of these proteins can change. If the change is significant enough, the antibodies generated by an older vaccine may not “fit” the new variant as well, potentially reducing the vaccine’s efficacy. By updating the antigen to LP.8.1, scientists are essentially updating the “Wanted” poster the immune system uses to identify and neutralize the virus.

Public Health Guidance and Implementation

Vaccination remains a cornerstone of the global public health strategy to prevent severe disease and death from COVID-19. The WHO recommends that Member States continue to offer vaccinations based on the guidelines provided by the WHO Strategic Advisory Group of Experts on Immunization (SAGE).

The TAG-CO-VAC continues to monitor the genetic evolution of SARS-CoV-2 and the performance of approved vaccines to provide timely updates to regulatory authorities and manufacturers worldwide.

Frequently Asked Questions

Do I need a new vaccine if I already had a JN.1 or KP.2 shot?

Vaccination schedules are determined by national health authorities based on WHO SAGE recommendations. Because the virus evolves, booster doses with updated antigens are often recommended to maintain protection.

How often does the WHO update these recommendations?

The TAG-CO-VAC typically holds decision-making meetings twice a year to review the evolution of the virus and the performance of current vaccines.

What happens if LP.8.1 isn’t available in my country?

The WHO states that JN.1 and KP.2 remain suitable alternatives. You should follow the guidance of your local health provider to receive the most appropriate available vaccine.

Looking Ahead

The transition to the LP.8.1 antigen underscores the reality of living with a mutating virus. As long as SARS-CoV-2 continues to evolve, the global health community will rely on agile monitoring and rapid vaccine updates to stay ahead of new variants and protect public health.