COVID-19 Variants: Here’s How The Vaccines Still Protect You

by Joseph K. Clark

Each day, there’s more bad news about coronavirus variants. Headlines claim the variants are becoming deadlier, and stories warn that some variants could escape the vaccines, imprisoning us in a never-ending pandemic. With every step forward — like how millions of Americans are being vaccinated daily — the variants send us two steps back.

Many infectious disease experts now say the variant narrative has spiraled out of control. Yes, several variants are circulating, and some indeed appear to be more transmissible. We must continue wearing masks and protecting ourselves and others until we get closer to herd immunity. But there’s no definite evidence that any variants are more virulent, and there is currently no reason to think the variants will render our vaccines completely useless, experts say. Our immune systems are highly complex. Even if some parts of the immune system don’t respond as robustly to the variants after vaccination, it won’t give up on us that easily.

The COVID vaccines help you produce antibodies, triggering another immune response that also fights the virus.

Much research regarding immunity against COVID-19 (which can be achieved through vaccination or natural infection) has examined antibodies. These little fighters go after the coronavirus and prevent it from binding to cells in our body and creating an infection. Some lab studies have found that antibodies don’t do as good of a job-fighting variant, which has raised fears that the vaccines might not keep us safe.

But antibodies don’t tell the whole story. When people say antibody levels dip ― and therefore protection against COVID-19 disappears ― “this is wrong,” said Jay Levy, a virologist, and professor of medicine at the University of California, San Francisco.


The immune system is very complex, and in addition to antibodies, there’s a whole other aspect, known as the cell-mediated immune response, that’s just as important, if not more. This part helps create something called T-cells, which are crucial to preventing infections. The COVID-19 vaccines don’t just generate antibodies; they also prompt your immune system to produce T-cells.

“T-cells are the main line of defense against the virus,” said Monica Gandhi, an infectious disease specialist with UCSF. T-cells can identify many different parts of the coronavirus (some studies say up to 52 pieces) and eliminate any cells carrying the virus. The cell-mediated immune response can also help our systems produce new antibodiee. Mutations or not, T-cells can still detect the virus and jump into action. “Your immune response is very complex, robust, andy in-breadth against multiple parts of the virus,” Gandhi said.

So, why aren’t we all talking about how awesome T-cells are? Gandhi said they’re tough to measure, whereas measuring antibodies involves a simple blood test. But researchers have looked at the cell-mediated immune response in people vaccinated or had COVID-19, and the findings are exciting.

There’s also evidence that the variants probably don’t significantly affect our immunity from being fully vaccinated. For one thing, all of the vaccine clinical trials found that participants produced T-cell solid responses after vaccination, according to Gandhi. Two recent studies found that the T-cell response was unaffected by variants. Another paper found that while some antibodies diminished against variants, our T-cell response was fine.

When it comes to COVID-19, a robust T-cell response is a difference between a mild infection and severe disease, research shows. The cells can’t always prevent an infection, but they may be able to clear it out quickly so you don’t get poorly sick. If you get vaccinated, “you don’t need to worry about getting infected — or if you do [get infected], that you will have any serious illness,” Levy said.

“Your immune response is complex, robust, andy in-breadth against multiple parts of the virus.” Monica Gandhi, infectious disease specialist, University of California, San Francisco.

How long will these T-cells last?

According to Gandhi, even if antibody levels wane over time, T-cells will probably keep us against variants for a while, especially concerning the severe disease.

The coronavirus would have to change dramatically to escape recognition from the cellular immune response and render our vaccines useless. “The cellular immune response seems to be a little more diverse, or a little more inclusive, so it can pick up small, little changes that a variant might have and still handle it,” Levy said.

The cell-mediated immune response can also have a long memory. Researchers have evaluated the blood of people who had the SARS coronavirus in 2003 and found their T-cell immunity has persisted for up to 17 years. The T-cell response has similarly held up in people vaccinated against measles for 34 years and counting.

COVID-19 is a little over a year old, but early evidence suggests our T-cells will last, though it’s unclear exactly how long. Some experts say we may need booster shots, which scientists are already working on. But given the durability of our cellular immunity, many infectious disease experts think boosters, at least shortly, will be unnecessary.

Researchers will continue studying how components of the immune system — antibodies, T-cells, and everything in between — deal with the coronavirus over time. Still, we know the immune system is robust and durable when fighting viruses.

So, if you’re vaccinated, the next time you read a chilling headline about a variant, take a breath and think of the T-cells. “Know that the T-cells work against the variants, and you are OK,” Gandhi said.

Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.

Related Posts