People can still get infected with COVID-19 if they've been vaccinated or have recovered from a COVID-19 infection. The immune-boosting antibodies that come from vaccines and earlier infections don't protect people 100% of the time.

Nonetheless, there's reason to be optimistic. People that recover from COVID-19 are estimated to have 95.2% protection from getting the sickness again. Vaccine protection against the virus varies. The Johnson & Johnson vaccine showed 66.3% efficacy at preventing COVID-19 infection in trials, while the Pfizer-BioNTech vaccine was 95% efficacious.

All of this means that you are much more likely to be protected against COVID-19 after getting a vaccine or recovering from infection. However, we can't say you'll be absolutely protected with 100% certainty. Currently, no vaccines prevent illnesses with 100% efficacy.

Variants are also part of the equation. Some variants can cause a change in how the virus spreads or how severe infections might be in people. Those factors can change how well the vaccines and prior COVID-19 infections protect against the evolving virus.

Researchers found that while the Pfizer vaccine works less well on new variants. It was 95% efficacious at preventing COVID-19 infections in clinical trials, but less so (89.5% effective) at protecting us from the COVID-19 B.1.1.7. variant. It protects even less (75% effective) against B1.3.5.1., a variant first identified in South Africa. 

To be sure, this doesn't mean vaccines don't work against concerning new variants. It does mean they could be less effective.

New mutations can eventually make the virus look quite different in comparison to its original form. That can help the virus evade vaccines and any protection caused from a prior infection.

However, natural antibodies which develop after you've recovered from COVID-19 may be relatively good at blocking new variants, studies show.

Experts are looking at something called an "escape mutation." It's named that because it seems to be particularly good at getting around any protection that vaccines or prior infection give us. It's likely that these types of mutations - the B.1.1.7. variant and B.1.3.5.1. variant - have this escape mutation.

Importantly, vaccines do protect particularly well (typically 95% or more) against severe, critical or fatal COVID-19.

It should also be noted that immune system cells—which remember past infections and react to them—may be able to change and attack harmful mutations in COVID-19 variants.

Experts can categorize three COVID-19 mutations if they begin showing they can spread more easily or cause worse forms of the disease: 1) variant of interest, 2) variant of concern, and 3) variant of high consequence. 

A variant of interest is a variant that causes an increase of COVID-19 cases or a cluster of cases, but has not yet expanded past that. Think of it as somewhere between a green and a yellow light on a stoplight. 

A variant of concern is a variant that causes: - An increase in the spread of COVID-19 - An increase in how severe the disease is after you contract it - More easily gets past protection from vaccines or natural infection.

Think of this as the yellow light on a stoplight. The B.1.1.7, B.1.351, P.1, B.1.427, and B.1.429 variants circulating in the United States are classified as variants of concern.

A variant of high consequence is a variant that has the same characteristics as the other variants but possibly worse. This type shows resilience against the prevention measures that work to stop other variants. Think of this as the red light on a stoplight. There are currently no COVID-19 variants categorized as variants of concern.