COMPLAINT
“Omicron XBB.1.5 subvariant may be more likely to infect those who are vaccinated, officials say”
DETAILS
Lack of context: The statement that the Omicron XBB.1.5 subvariant was “perhaps more likely” to infect vaccinated people was intended to be a comparison of XBB.1.5 with other variants, non-vaccinated versus unvaccinated people.
Inadequate support: There is no evidence to support the claim that vaccinated people are more vulnerable to XBB.1.5 infection. Evidence so far indicates that unvaccinated people are more likely to develop COVID-19 and die than vaccinated people.
KEY TAKE AWAY
The Omicron XBB.1.5 variant contains several mutations that make it more infectious and better able to evade the immune system. Vaccination against COVID-19 is highly effective in protecting people from severe COVID-19 and from death and, to a lesser extent, from infection as well. The data so far indicates that unvaccinated people are more likely to develop COVID-19 and die than vaccinated people.
COMPLETE CLAIM: “Omicron XBB.1.5 subvariant may be more likely to infect those who are vaccinated, officials say”
REVISION
A chirp of the New York City Department of Health and Mental Hygiene (@nychealthy), published January 13, 2023, generated confusion over its statement that “Omicron subvariant XBB.1.5 now accounts for 73% of all COVID-19 cases sequenced in New York. XBB.1.5 is the most transmissible form of COVID-19 that we know of to date and may be more likely to infect people who have been vaccinated or have already had COVID-19.”
Responses to the tweet showed that some social media users interpreted the statement to mean that vaccinated people are more vulnerable to XBB.1.5 infection than unvaccinated people (see examples here And here). This impression was also reinforced by the clickbait title of a FoxNews article on the same tweet: “Omicron’s XBB.1.5 subvariant may be more likely to infect those who are vaccinated, officials say.”
The Fox News article amassed more than 2,700 user interactions on Twitter according to social media analytics tool CrowdTangle. Most of these can be attributed to Henning Rosenbusch, a journalist with more than 39,000 Twitter followers, who shared a screenshot of the Fox News article, calling it “a pandemic of the vaccinated”. Robert Malone, a former scientist who has repeatedly claimedinaccurate, that COVID-19 vaccines are not safe, also shared the Fox News article on Twitter, accompanied by the remark “Who could have predicted this!!??!!” and a sunglasses emoji.
However, the claim is false, like Ajay Sethi, an epidemiologist and professor at the University of Wisconsin-Madison, told Health Feedback. The original tweet from the @nychealthy account lacked context, specifically, exactly what the term “most likely” was used for. [Read Sethi’s full comments here.]
“Implied but not explicitly stated is that XBB.1.5 is more likely to infect people who have vaccine immunity or a previous COVID-19 infection compared to the previous variants,” he explained.
Indeed, this is supported by the fact that the tweet also contains a graph illustrating the proportion of variants for tested COVID-19 cases, showing how cases caused by XBB.1.5 are gradually increasing over time and outnumbering other variants. Below is a screenshot of the full tweet.
Figure 1. A screenshot of @nychealthy’s tweet, showing a graph of the proportion of variants for tested cases of COVID-19 in New York.
The New York Health website it also provides additional context that clarifies what the intended meaning of the tweet was: “It may be more likely to infect people who have been vaccinated or who previously had COVID-19 compared to the previous variants.” [emphasis added]
However, the insufficient context in the tweet made it easy for some users to choose a frame of reference that suited their views. “In this case, they are incorrectly comparing the likelihood of infection between vaccinated and unvaccinated people,” Sethi explained, when in reality it is a comparison of different variants.
Health Feedback has reached out to the New York City Department of Health and Mental Hygiene for comment. We will update this review if new information becomes available.
XBB.1.5 is the latest in a series of variants causing concern among scientists and public health agencies in the United States And Europe. Certain mutations it carries make the variant more infectious and better able to evade the immune system than previous variants, allowing XBB.1.5 to outcompete other variants. As data from the US Centers for Disease Control and Prevention (CDC) show, cases caused by XBB.1.5 have been steadily increasing since early January 2023.
Figure 2. The proportion of SARS-CoV-2 variants detected in tested cases of COVID-19 in the United States Source: US CDC. Data retrieved January 17, 2023.
Much of the concern stems from the possibility that XBB.1.5’s high infectivity and ability to evade immune defenses could cause an increase in cases and hospitalizations. But right now, there isn’t enough evidence to determine whether XBB.1.5 is more likely to cause serious disease.
There is no evidence that XBB.1.5 preferentially infects vaccinated people over unvaccinated people, as some have claimed. And as the graphs below show, the evidence we have so far indicates that it is unvaccinated people who are more likely to become infected and die of COVID-19 than vaccinated people.
Figure 3. The COVID-19 case rate by vaccination status. Source: US CDC. Data retrieved January 17, 2023.
Figure 4. The rate of deaths from COVID-19, by vaccination status. Source: US CDC. Data retrieved January 17, 2023.
THE ANSWERS OF SCIENTISTS
Ajay Sethi, professor (Population Health Sciences), University of Wisconsin-Madison:
The claim that “Vaccinated people are more likely than unvaccinated people to contract the Omicron XBB.1.5 variant.” it’s false.
The new XBB.1.5. the variant has a growth advantage over BQ.1 and BQ.1.1. variants and is becoming the new dominant form of circulating SARS-CoV-2. This replacement of other variants with XBB.1.5 has begun in New York and other northeastern states as shown on the CDC COVID Data Locator.
A growth advantage may be due to the fact that a new variant is more infectious than the previous ones or less affected by the immunity already present in the population or by a combination of both, as in the case of XBB.1.5.
The original tweet from @nychealthy (below) is missing some important context, especially a “compared to…” statement.
It is implied but not explicitly stated that XBB.1.5 is more likely to infect people who have immunity from the vaccine or a previous COVID-19 infection than the previous variants.
Without that context, people who lack confidence or choose to spread misleading information about COVID-19 vaccines fill in that missing information, consciously or subconsciously, with words that fit their false opinions. In this case, they incorrectly compare the likelihood of infection between vaccinated and unvaccinated people. The original tweet was well-intentioned, but misinformation speakers and users took advantage of the missing context.