The result of this awareness is that the COVID-19 vaccines developed so far showed no signs of ADE in animal studies, clinical trials, or during vaccine rollout. Real-world studies further demonstrate that all FDA-authorized are in preventing severe disease and death[5,6]. Furthermore, infections in fully vaccinated individuals and tend to produce milder symptoms than in those who didn’t receive the vaccine[6,7]. This is exactly the opposite of what one would expect if ADE was occurring.
During the interview, Malone further claimed that SARS-CoV-2 variants are “most likely developing in the people who have been vaccinated”, increasing the risk of ADE. As Health Feedback explained in
, current evidence doesn’t support the claim that COVID-19 vaccines lead to more viral variants, and actually contradicts it.
Each time the virus replicates, it can introduce
, which are changes in its genetic sequence. These changes are random and a natural process in viral evolution. The more infections the virus causes, the more times it replicates, increasing the likelihood of generating new mutations that might spread as new variants. Some studies suggest that
also favor the development of new mutations.
Because COVID-19 vaccines
, they also make it less likely for the virus to mutate and for new variants to spread. In contrast, unvaccinated individuals are
to get infected and develop severe COVID-19, increasing the chances of
to emerge. If COVID-19 vaccines did lead to more variants, those regions with higher vaccination rates would observe more new variants circulating among the population. This isn’t the case. In fact, all current
emerged in 2020, before the vaccination campaigns began.
Given the above evidence that COVID-19 vaccines aren’t worsening the disease, on what grounds claimed Malone that COVID-19 vaccines cause ADE?
During the interview, Malone mentioned a
by
NBC News discussing an imminent update on
from the U.S. Centers for Disease Control and Prevention (CDC). This update reversed previous indoor mask-wearing policy and recommended that fully vaccinated people wear masks indoors again in places with high transmission rates.
According to Malone,
NBC News reported that this change in guidance responded to new data suggesting that people vaccinated against COVID-19 had more virus than unvaccinated individuals. Malone also shared this claim in a
, together with a screenshot from a
echoing that of
NBC News.
USA Today removed this part of the article in a
. However, neither
NBC News nor
USA Today stated what Malone claimed they did. Instead, what they reported:
“The Biden administration is issuing new guidance Tuesday recommending indoor mask use in areas with high transmission rates, after reviewing new data suggesting fully vaccinated individuals are not just contracting Covid-19, but could also be carrying higher levels of virus than previously understood and potentially able to infect others, according to multiple sources close to the discussion.” — NBC News.
“NBC News, citing unnamed officials aware of the decision, reported it comes after new data suggests vaccinated individuals could have higher levels of virus and infect others amid the surge of cases driven by the delta variant of the coronavirus.” — USA Today.
Multiple studies show that the few people who develop COVID-19 after receiving the Pfizer-BioNTech COVID-19 vaccine tend to have a
than unvaccinated people[8,9]. New data suggest that viral levels in vaccinated individuals who get infected with the Delta variant might be as high as in unvaccinated individuals, but not higher as Malone claimed[10]. These data imply that some vaccinated individuals who get infected might still transmit the virus to others. This is what informed the CDC’s decision to reverse face mask policy, as the
NBC News article reported.
In summary, Malone misrepresented the
NBC News article to claim that vaccinated individuals have higher virus levels than unvaccinated individuals, which is inaccurate. Vaccinated people who become infected generally tend to have a lower viral load compared to unvaccinated people. However, when infected with the Delta variant in particular, viral loads in vaccinated individuals can be similar to those in unvaccinated people, but not higher.
COVID-19 vaccines are highly effective in preventing severe COVID-19 and reducing the risk of infection. Malone’s claim that the COVID-19 vaccines cause ADE is contradicted by the fact that vaccinated individuals who become infected tend to have milder symptoms than unvaccinated individuals, rather than the opposite. By reducing the risk of infection and severe disease, COVID-19 vaccines also limit the spread of the virus within the population, making it less likely for new variants to emerge.
READ MORE
The medicinal chemist Derek Lowe conducted a a
of ADE in the context of COVID-19 vaccines in his blog on
Science Translational Medicine. He also discussed previous research on ADE in different diseases and the mechanisms that can lead to the phenomenon.
