CDC guidance on new Covid strain misrepresented online

Social media users claim the US Centers for Disease Control and Prevention (CDC) has warned that people vaccinated against Covid-19 face a greater risk from a new strain of the virus than the unvaccinated. This is false; the posts misconstrue an agency assessment that says the new variant may be better at evading antibodies.

"The CDC have said that people who could get this variant are actually more likely to get it if they've been vaccinated so we're in a situation now where vaccination according to the CDC is increasing the likelihood of infection," says John Campbell in an August 29, 2023 YouTube video.

Campbell, a self-described retired nurse from England, has more than 2.8 million subscribers on his channel, which has previously promoted misinformation about the pandemic.

The claims come days after public health authorities warned of the emergence of a highly mutated new strain of the coronavirus named BA.2.86.

"Apparently you are more susceptible and more likely to contract BA.2.86 if you have been VACCINATED," says an August 30 post on X, formerly known as Twitter.

Similar allegations spread elsewhere on Instagram, Facebook and X.

<span>Screenshot of an X post taken August 31, 2023</span>
Screenshot of an X post taken August 31, 2023
<span>Screenshot of an X post taken August 31, 2023</span>
Screenshot of an X post taken August 31, 2023

The posts misrepresent an August 23 CDC assessment (archived here) about the new variant, which health officials have said can evade immunity.

"BA.2.86 may be more capable of causing infection in people who have previously had Covid-19 or who have received Covid-19 vaccines," the CDC statement says.

However, claims that vaccinated individuals are more susceptible than the unvaccinated are baseless.

"I don't know of any data that supports this claim," said Adam Lauring, a University of Michigan virologist whose lab identified one person with the new variant, in an August 31 email.

Craig Wilen, an associate professor  of laboratory medicine and immunobiology at Yale University, agreed.

"I don't know of any data that suggests this is true," he said in an August 30 email. "Frankly, it's far-fetched and makes absolutely zero biological sense."

In an updated August 30 statement (archived here), the CDC said immunity from vaccines and prior infections still affords some protection against the new variant, which was first identified in Israel before spreading to other countries.

"Approximately 97 percent of the US population has antibodies to SARS-CoV-2 from vaccination, previous infection or both (hybrid immunity)," the agency said.

"It is likely that the humoral and cellular immune responses will continue to provide protection against severe disease from this variant."

The CDC still recommends vaccination.

"CDC's current assessment is that the updated Covid-19 vaccine, which will be available in mid-September, will likely be effective at reducing severe disease and hospitalization," the agency said in its statement.

More of AFP's reporting on vaccine misinformation is available here.