There is no single “best” COVID-19 vaccine. The CDC states there is no preference for one vaccine over another when more than one is recommended for your age group. All three available options, Pfizer, Moderna, and Novavax, protect against severe illness, hospitalization, and death. The most important factor is getting whichever one is available to you and staying current with the latest formulation.
That said, the vaccines do differ in meaningful ways: the technology behind them, who can receive them, and which viral strain they target. Those differences may matter depending on your age, health status, or personal preferences.
Three Vaccines, Two Technologies
Pfizer and Moderna both use mRNA technology. They deliver genetic instructions that teach your cells to produce a piece of the virus’s spike protein, triggering an immune response. For the 2025-2026 season, both target the LP.8.1 strain, which is part of the JN.1 lineage and closely matches the variants currently circulating in the United States.
Novavax takes a different approach. It’s a protein-based vaccine, meaning it delivers a lab-made version of the spike protein directly, paired with an ingredient that boosts the immune response. Novavax targets the JN.1 strain rather than LP.8.1 specifically. Protein-based vaccines use a more traditional technology that has been employed in other vaccines for decades, which appeals to some people who prefer an alternative to mRNA.
All three protect against the same thing: serious COVID-19 illness. The practical difference for most people comes down to availability and eligibility.
Who Can Get Which Vaccine
Your age determines which vaccines are an option. For children aged 6 months through 4 years, only Moderna is currently approved. Pfizer is no longer authorized for this age group. Starting at age 5, both Moderna and Pfizer become available. Novavax enters the picture at age 12 and older.
If you’re an adult with no strong preference, you can choose any of the three. If you had a notable reaction to one brand previously, switching to a different one for your next dose is a safe and accepted option. The CDC and FDA have reviewed data on mixing vaccine brands and confirmed it’s fine, though there isn’t strong evidence that mixing provides any extra benefit on its own.
How Well the Current Vaccines Work
Real-world data from the 2024-2025 season gives a clear picture of what to expect. Among adults 65 and older without immune-compromising conditions, the updated vaccine reduced COVID-related hospitalizations by about 46%, measured roughly two months after vaccination. For immunocompromised adults in the same age group, that figure was 40%.
Protection was stronger in young children. For kids aged 6 months through 4 years, the vaccine was 76% effective at preventing emergency department and urgent care visits in the first six months, and that held steady at 77% out to about 10 months. Older children and teens (ages 5 through 17) saw 56% effectiveness in the first six months, which dropped to 45% by 10 months.
These numbers reflect protection against illness serious enough to send someone to a hospital or urgent care. Protection against the most severe outcomes, like ICU admission or death, is generally higher, though hospitalization rates during the study period were too low to calculate those figures precisely.
How Long Protection Lasts
Immunity from COVID vaccines wanes over time, which is why updated formulations are released annually. The pediatric data shows a pattern: protection stays relatively stable for the first six months, then begins to decline, particularly in older children and teens. This is consistent with what’s been observed in adults across multiple vaccine seasons.
For most healthy people, a single annual dose of the updated vaccine is the current recommendation. The timing aligns with fall, similar to the flu shot, to provide the strongest protection heading into winter when respiratory viruses circulate most.
Recommendations for Older Adults
Adults 65 and older are specifically flagged as a priority group for vaccination. Age remains one of the strongest risk factors for severe COVID-19, and the vaccine’s 46% reduction in hospitalizations in this group represents a meaningful layer of protection. There is no preferred brand for seniors. Pfizer, Moderna, and Novavax all perform the same essential function, and any of the three is a good choice.
What’s Different for Immunocompromised People
If you have a condition that weakens your immune system, or you take medications that suppress it, the vaccination schedule looks quite different. Rather than a single annual dose, the CDC recommends a multi-dose approach.
For immunocompromised people who have never been vaccinated, the initial series involves three doses spaced a few weeks apart, followed by a fourth dose six months later. If you’ve already completed a primary series in the past, the current guidance calls for two doses of the 2025-2026 vaccine, spaced six months apart.
This modified schedule exists because immunocompromised individuals build a weaker immune response from each dose. Spacing out additional doses helps reinforce that response over time. The 40% reduction in hospitalizations observed in immunocompromised seniors, while lower than the 46% seen in healthier adults, still represents substantial protection.
Practical Tips for Choosing
If you’re trying to decide between the three, here are the factors that actually matter:
- Children under 5: Moderna is your only option.
- Children 5 to 11: Moderna or Pfizer, but not Novavax.
- Ages 12 and up: All three are available. Choose based on what your pharmacy carries.
- Previous bad reaction to an mRNA vaccine: Novavax gives you a non-mRNA alternative.
- Preference for traditional vaccine technology: Novavax uses a protein-based approach rather than mRNA.
An eight-week interval between first and second doses (rather than the minimum three to four weeks) may reduce the already-rare risk of heart inflammation associated with COVID vaccines. This applies mainly to younger people starting their initial series.
Beyond these specifics, the choice between brands matters far less than whether you get vaccinated at all. The updated formulas are redesigned each year to match circulating strains, and staying current is what keeps protection meaningful.