By Chris Nichols

Updated at 10:54 a.m. on September 24, 2021

Reports about vaccinated Americans catching COVID-19 are energizing vaccine skeptics and leading to more misinformation about efficacy and breakthrough cases.

CapRadio’s PolitiFact California Reporter Chris Nichols examined the facts about breakthrough infections in this week’s Can You Handle The Truth.

Nichols sat down and spoke with CapRadio’s afternoon anchor Randol White and broke everything down.

This interview has been edited for clarity and length.

Interview Highlights

On how rare breakthrough COVID-19 cases are feeding into misinformation

One example is a popular and misleading post on Instagram.

It wrongly claimed that the vaccines are “the first in history to not prevent people from catching or spreading a virus” and that they only last a few months.

PolitiFact found that is completely false. No vaccine is 100% effective. That’s the case for the flu vaccine and also the case for the COVID-19 vaccines.

The U.S. Centers for Disease Control and Prevention says on its website some fully vaccinated people will get sick, some will even be hospitalized or die from COVID-19, and that vaccinated people with breakthrough infections can also spread the disease.

On current COVID-19 cases in unvaccinated people

Studies show vaccinated people are eight times less likely to be infected — and 25 times less likely to be hospitalized or die from COVID-19 than unvaccinated people, according to the CDC.

And those who are fully vaccinated and get one of these breakthrough cases are less likely to suffer a serious illness.

On the false claim that vaccine efficacy ‘only lasts for months’

It’s still not clear how long the protection provided by the vaccines will last. Health officials are still debating whether everyone will need a booster shot.

But the last part of the social media post is misleading because plenty of other vaccines require boosters.

People are asked to take the flu vaccine every year, and vaccines against Hepatitis B, whooping cough, chickenpox and measles all require multiple shots.

On the odds of a fully vaccinated person developing a breakthrough case

The New York Times found that the average vaccinated American’s odds of getting a breakthrough infection are roughly 1 in 5,000 a day, or 1 in 10,000 in highly vaccinated states.

They used data on daily average COVID-19 cases in different parts of the country to arrive at these odds.

A recent CDC report includes data showing the odds of a breakthrough might be even lower, at about 1 in 5,000 per week.

PolitiFact found all of these statistics have some limitations. For example, they don’t take into account the undercounting of breakthrough infections. But, they do show the vaccines are reducing infections and the overall risk of a breakthrough is low.

Correction: A previous version of this story misstated the risk of breakthrough infections. They are rare, but not exceedingly rare.