Four COVID-19 vaccines are approved for use in the United States for the 2025–2026 season: Moderna Spikevax, Moderna mNexspike, Pfizer-BioNTech, and Novavax. Which ones you can get depends on your age, and the vaccines use two different technologies to train your immune system.
Approved Vaccines by Age Group
The youngest children have the fewest options. For kids ages 6 months through 4 years, only Moderna Spikevax is approved. Children ages 5 through 11 can receive either Moderna Spikevax or the Pfizer-BioNTech vaccine.
Starting at age 12, all four options open up: Moderna Spikevax, Moderna mNexspike, Pfizer-BioNTech, and Novavax. The same four remain available for adults 65 and older. Novavax is given as a single dose for initial vaccination, which makes it a straightforward choice for people getting their first COVID vaccine.
mRNA Vaccines vs. Protein-Based Vaccines
Three of the four available vaccines (both Moderna products and Pfizer-BioNTech) use mRNA technology. These work by delivering a small piece of genetic code, wrapped in a tiny fat particle, into your cells. Your cells read that code and temporarily produce a copy of the spike protein found on the surface of the virus. Your immune system recognizes the spike protein as foreign, mounts a response, and builds memory cells that can respond faster if you encounter the real virus later.
Novavax takes a different approach. It’s a protein subunit vaccine, a type that’s been used in other vaccines for decades. Instead of instructing your cells to make the spike protein, Novavax delivers a lab-grown version of the spike protein directly, paired with an ingredient called an adjuvant that amplifies your immune response. The spike protein is grown in insect cells, a well-established method for producing complex proteins in the right shape. If you prefer a vaccine that doesn’t use mRNA technology, Novavax is currently the only non-mRNA option in the U.S.
What Strain the Vaccines Target
COVID vaccines are updated to match circulating variants, similar to the annual flu shot. The World Health Organization’s advisory group most recently recommended that vaccines target the LP.8.1 lineage, a descendant of the Omicron family. Vaccines using the earlier JN.1 or KP.2 formulations are still considered suitable alternatives, and the WHO has advised that vaccination should not be delayed while waiting for the newest composition.
During the 2024–2025 season, the primary circulating lineages were descendants of Omicron JN.1, including KP.2, KP.3, and XEC. The virus continues to evolve, which is why vaccine formulations are periodically updated.
How Well Current Vaccines Work
CDC data from September 2024 through January 2025 provides the clearest picture of recent vaccine performance. Among adults 18 and older, the updated vaccine reduced the risk of a COVID-related emergency department or urgent care visit by 33% compared to being unvaccinated. Protection against hospitalization was stronger: 45% to 46% among immunocompetent adults 65 and older, and 40% among older adults with weakened immune systems.
These numbers reflect protection during the first four months after vaccination. The vaccines are more effective at preventing severe illness and hospitalization than at stopping milder infections entirely, a pattern that has held since the Omicron era began.
Common Side Effects
Side effects are similar across all available vaccines and are typically mild. The most common is soreness at the injection site. Beyond that, you may experience fatigue, headache, muscle pain, joint pain, chills, or a low fever. These reactions usually appear within a day or two and resolve quickly. In young children, the most common responses are fussiness, decreased appetite, and sleepiness.
Serious reactions are rare. Anaphylaxis, a severe allergic reaction, occurs at a rate of roughly 5 cases per million doses. An earlier vaccine from Johnson & Johnson (no longer available in the U.S.) was associated with a rare blood clotting condition at a rate of about 4 per million doses, with somewhat higher rates in women ages 30 to 49. That vaccine has been withdrawn, and this particular risk does not apply to the four currently approved products.
Cost and Access
The federal Bridge Access Program, which previously provided free COVID vaccines to uninsured adults, ended before its planned closure date due to congressional funding cuts. Some providers who were enrolled in the program received a limited supply of doses, but availability is not guaranteed. If you have insurance, COVID vaccines are generally covered at no cost. If you’re uninsured, your best option is to call local pharmacies or community health centers directly to ask about available stock and pricing.
Vaccines Available Outside the U.S.
Several COVID vaccines authorized in other countries are not available in the United States. The WHO maintains an Emergency Use Listing that includes products like Corbevax, a protein subunit vaccine made by Biological E. Limited in India. If you’re traveling internationally or living abroad, the vaccines offered to you will depend on your country’s regulatory approvals. The core technologies, mRNA and protein-based, are the same ones used globally, even though brand names and manufacturers differ.