COVID-19 Vaccines: What You Need to Know (And Why It Still Matters)
Discover how COVID-19 vaccines work, the different types available, their safety, effectiveness, and common questions answered—so you can make informed decisions about your health.
HEALTHCARE SERVICES
Dr. S. Ali
5/28/20254 min read


Remember when COVID-19 first turned our world upside down? Fast forward to today, and vaccines have become one of the most powerful tools we have in protecting ourselves and those around us. But with so much information (and misinformation) out there, it’s easy to feel confused about COVID-19 vaccines—how they work, whether you still need one, and what the latest recommendations are.
Let’s break it down in a simple, no-stress way.
How Do COVID-19 Vaccines Work?
Think of a COVID-19 vaccine like a training course for your immune system. Instead of using the whole virus, vaccines safely expose your body to just one part of it—usually a harmless version of the spike protein, which is the part the virus uses to enter your cells.
Depending on the type of vaccine, your body either:
Gets a small piece of the spike protein directly (like in the Novavax vaccine),
or
Receives instructions to make the spike protein—
– through mRNA (like in the Pfizer and Moderna vaccines), which tells your cells how to temporarily produce the spike protein,
– or via a viral vector (like the Johnson & Johnson vaccine), which uses a harmless, non-replicating virus to deliver those instructions.
Once your immune system sees the spike protein, it recognizes it as a threat and starts building antibodies and memory cells. This means your body learns how to defend itself—without you ever getting sick from the virus itself.
So later, if you’re exposed to the real COVID-19 virus, your immune system can jump into action right away—quickly attacking the virus and helping prevent severe illness.
Types of COVID-19 Vaccines
mRNA Vaccines (Pfizer-BioNTech & Moderna): These vaccines use messenger RNA to instruct your cells to produce a harmless piece of the spike protein, prompting an immune response.
Viral Vector Vaccines (Johnson & Johnson): Utilize a modified, harmless virus to deliver genetic instructions to your cells to produce the spike protein, triggering immunity.
Protein Subunit Vaccines (Novavax): Introduce a lab-made version of the spike protein directly into the body, along with an adjuvant called Matrix-M to enhance the immune response.
Newer, updated versions (often called bivalent vaccines) are now being offered to protect against both the original virus strain and newer variants like Omicron.
Why You Still Need a COVID-19 Vaccine or Booster
You might be wondering, “Do I still need a COVID shot?” Here’s the deal:
Immunity from earlier doses or infections fades over time.
New variants continue to emerge, and updated vaccines offer better protection against them.
Even if you’re healthy, getting vaccinated helps protect vulnerable people around you—like older adults and those with chronic conditions.
Getting your booster keeps your immune system sharp, especially heading into cold and flu season.
Can You Still Get COVID After the Vaccine?
Yes.
Why Can You Still Get COVID After the Vaccine?
Vaccines are designed to train your immune system to recognize and fight the virus, but no vaccine is 100% effective at preventing infection in every single person. Here’s why breakthrough infections can happen:
Variants: The virus can change over time, creating new variants that might partially evade the immune response triggered by the vaccine. This can make it easier for some vaccinated people to get infected.
Immune Response Variability: Everyone’s immune system responds differently. Some people might build stronger immunity from the vaccine than others, depending on factors like age, health conditions, or medications.
Exposure Level: If you are exposed to a very high amount of virus (like in close, prolonged contact with someone who is infected), even a vaccinated immune system might take longer to fully stop the infection.
But here’s the good news:
Even if you do get infected after vaccination (called a breakthrough infection), your body is much better prepared to fight the virus quickly. Vaccinated people are far less likely to get seriously ill, hospitalized, or die from COVID-19.
So, the vaccine is like a powerful shield—not perfect, but strong enough to protect you from the worst outcomes of COVID-19.
Who Should Get Vaccinated Now?
According to the latest CDC guidance:
Everyone 6 months and older should stay up to date with COVID-19 vaccines.
People 65 and older, or those with weakened immune systems, are advised to get an additional booster if it's been more than 4 months since their last dose.
If you've had COVID recently, you may wait about 3 months before your next vaccine—talk to your doctor for personal advice.
Common Questions
Q: Are COVID-19 vaccines safe?
Yes. Millions of people have safely received them. Mild side effects like arm soreness or fatigue are normal signs that your body is building protection.
Q: Are COVID vaccines free?
In most places, yes. Vaccines are typically available at local pharmacies, clinics, and health departments—often at no cost.
Q: What about side effects?
Most are mild and go away in a day or two. Serious side effects are extremely rare, and the benefits far outweigh the risks.
Q: Can you get COVID-19 from the vaccine?
No. COVID-19 vaccines do not contain the live virus that causes COVID-19, so they cannot give you the illness. Instead, they help your immune system recognize and fight the virus if you are exposed. Some side effects like tiredness or a sore arm may occur, but these are signs your body is building protection—not the disease itself.
Final Thoughts
COVID-19 is still here, but thanks to vaccines, it’s a lot more manageable. Staying up to date with your shots is one of the simplest and most effective ways to protect yourself and your community.
Sources:
COVID-19 Vaccine Basics
https://www.cdc.gov/covid/vaccines/how-they-work.htmlCDC+1CDC+1Explaining How Vaccines Work
https://www.cdc.gov/vaccines/basics/explaining-how-vaccines-work.html
COVID-19 Vaccine Safety
https://www.cdc.gov/vaccine-safety/vaccines/covid-19.htmlSafety Considerations for COVID-19 Vaccines
https://www.cdc.gov/covid/hcp/vaccine-considerations/safety-considerations.htmlMayo Clinic: Different Types of COVID-19 Vaccines
Yale Medicine: Novavax's COVID-19 Vaccine
https://www.yalemedicine.org/news/novavax-covid-vaccine