Yes, there are COVID-19 vaccines widely available in the United States, and they are updated regularly to match circulating virus strains. The current 2024-2025 formula targets newer variants and is available to anyone six months of age and older.
Which Vaccines Are Available Now
Two mRNA vaccines make up the current options in the U.S. The Pfizer-BioNTech vaccine (branded as Comirnaty for ages 12 and up) and the Moderna vaccine (branded as Spikevax for ages 12 and up) are both fully approved by the FDA for the 2024-2025 season. For children between 6 months and 11 years old, both vaccines are available under emergency use authorization, which means they’ve cleared safety and efficacy reviews but haven’t gone through the full approval process yet.
A third option, the Novavax vaccine, uses a different technology (more on that below) and has been available in prior seasons. The two mRNA vaccines remain the most widely distributed.
How the Vaccines Work
The mRNA vaccines from Pfizer and Moderna deliver a small set of genetic instructions to your cells. Those instructions tell your cells to build a harmless copy of the spike protein found on the surface of the COVID-19 virus. Your immune system spots these spike proteins, recognizes them as foreign, and builds antibodies against them. If you encounter the real virus later, your body already knows how to fight it. The mRNA itself breaks down quickly and doesn’t alter your DNA.
The Novavax vaccine takes a different approach. Instead of giving your cells instructions, it delivers pre-made spike proteins directly. Your immune system reacts to those proteins the same way, producing antibodies and defensive white blood cells. This is a more traditional vaccine technology, similar to what’s used in hepatitis B and whooping cough vaccines. Some people who prefer not to receive mRNA vaccines have opted for this route.
How Well They Work Against Current Variants
COVID-19 vaccines are updated to keep pace with the virus as it evolves, much like the annual flu shot. The 2024-2025 formula is designed around the JN.1 variant lineage. Real-world data from the CDC found that the updated vaccine reduced COVID-related emergency department and urgent care visits by 33% among adults 18 and older. For adults 65 and older without weakened immune systems, it cut hospitalization risk by 46%. For immunocompromised adults in the same age group, hospitalization risk dropped by 40%.
These numbers reflect protection against infection severe enough to require medical care, not mild cases. The vaccines are consistently better at preventing serious illness than preventing infection altogether, which has been true since the earliest versions.
Newer subvariants like KP.3.1.1 and XEC have shown some ability to dodge immune defenses. Lab studies published in The Lancet Infectious Diseases found that before a booster, antibody levels against KP.3.1.1 and XEC were about 5 to 5.5 times lower than against JN.1. After vaccination, neutralizing antibody levels jumped dramatically for all variants tested: roughly 15 times higher for KP.3.1.1 and 11 times higher for XEC. The newer variants still weren’t neutralized quite as effectively as JN.1 itself, but the boost was substantial enough that researchers expect meaningful protection against hospitalization and long-term complications.
Common Side Effects
Most side effects are mild and short-lived. Soreness at the injection site, fatigue, headache, muscle aches, and low-grade fever are the most frequently reported reactions. These typically show up within a day or two and resolve on their own within 24 to 48 hours. They’re signs that your immune system is responding to the vaccine.
Serious reactions are rare. Anaphylaxis, a severe allergic reaction, occurs in roughly 5 cases per million doses. This is why vaccination sites ask you to wait 15 minutes after your shot. An older vaccine (the Johnson &Johnson version, no longer available in the U.S.) was linked to a blood clotting condition at a rate of about 4 cases per million doses, with slightly higher rates in women ages 30 to 49. That vaccine was pulled from the U.S. market, and the issue has not been associated with the mRNA vaccines.
Who Should Get Vaccinated
The updated vaccine is recommended for everyone six months of age and older. It’s especially important for people at higher risk of severe COVID-19: adults 65 and older, people with chronic health conditions like diabetes or heart disease, pregnant individuals, and those with weakened immune systems. Even if you’ve had COVID-19 before, vaccination adds a layer of protection. The combination of prior infection and vaccination produces a broader immune response than either one alone.
If you received an earlier version of the vaccine, the updated 2024-2025 dose is designed to work regardless of how many previous shots you’ve had. You don’t need to start over or follow a specific sequence from earlier rounds of vaccination.
Cost and Where to Get It
For most people in the U.S., the vaccine is free. Private health insurance, Medicare, and Medicaid plans generally cover COVID-19 vaccination without cost-sharing when you go to an in-network provider. Check your specific plan for details, since network restrictions can vary.
A federal program called the Bridge Access Program previously covered vaccines for uninsured adults, but it ended in late 2024. If you don’t have insurance, your state or local health department immunization program may still offer the vaccine at no cost. Pharmacies and community health centers are the most common vaccination sites. Many allow walk-ins, though scheduling an appointment ensures the vaccine is in stock when you arrive.