Variant Omicron: does the vaccine promote Covid infection via “facilitating antibodies”?

Anxious to combat false information on a daily basis, the Verifiers team has entered into a partnership with the National Institute for Health and Medical Research (Inserm). Objective: to interview the most seasoned researchers and answer the questions that Internet users are asking about the coronavirus and vaccination.

Today it is a question of deciphering the new theory in vogue in the anti-vaccine sphere. For lack of having been able to demonstrate that the 9.68 billion doses inoculated in the world involved a danger, opponents of vaccination now believe that, faced with the new Omicron variant, the vaccine “promotes infections” because of the “facilitating antibodies”. At the head of the gondola, Florian Philippot, anti-mask and anti-restrictions activist who predicted this Monday, January 17 on Twitter that this new theory, popularized by Didier Raoult, would put “very, very angry” the French. But is it even believable? We put the question to Professor Xavier de Lamballerie, Director of the Emerging Viruses Unit (Inserm, Aix-Marseille University).

To support his new hypothesis of the moment, Professor Didier Raoult started from a single observation. Vaccinated people who tested positive at the IHU would test positive within two weeks. He also asserted (erroneously, as we demonstrate here) that the most vaccinated countries are those which record the most contamination. Proof therefore, in the eyes of this microbiologist pinned by the Order of Physicians, that the vaccine would produce “facilitating antibodies”.

This theory, which the defender of hydroxychloroquine does not support with any specific study, transposes to Covid-19 a mechanism observed with dengue fever. In the model of this mosquito-borne tropical disease, “we know that certain antibodies, particularly those that are not very effective, can cling to the virus and bring it to immune cells”, as summarized by Professor Xavier de Lamballerie. The latter, equipped with specific receptors, seize this antibody “actually linked to the virus, which then infects the cell”. Like a Trojan horse. A phenomenon found behind the acronyms ADE, for antibody-dependent enhancement (antibody dependent worsening) or VAED, for vaccine-associated enhanced disease (disease aggravated by vaccination).

If this phenomenon has “passionate the world of science for several decades” by our interlocutor’s own admission, it is not “absolutely not systematic”. With dengue, this mechanism cannot be observed “only in very specific circumstances”. Namely, when a person who has already had an episode of dengue, with one of the four existing serotypes, has a second infection with a different serotype. And even in this case, “facilitation by antibodies is not systematic, but it has been proposed that it is one of the determinants of severe forms of the disease”.

A mechanism “Very peculiar”, unique to this virus, which has four different stereotypes, and which cannot be transferred so easily to the current epidemic. In fact, for this hypothesis to be valid, it would be necessary that the immunity cells which hook the antibody-virus complex can be infected by Covid-19, as is observed for the dengue virus. However, to date “no scientific and factual element shows it”, notes Xavier de Lamballerie.

And it’s not for lack of having paid particular attention to it. The issue of facilitative antibodies has been monitored since the start of vaccine development. There is also an article on this subject in the medical dictionary Vidal. Dated November 3, 2020, it then summarized the questions and uncertainties on this subject. Faced with a vaccine at the threshold “minimum efficiency (…) set at 50% by regulatory agencies”, it thus seemed important in the eyes of the scientific community that “the hypothesis” of an ADE or VAED phenomenon either “studied”.

Analysis made from the first clinical and preclinical laboratory trials. “All laboratories proposing vaccine candidates had to submit data on the absence of antibody facilitation to regulatory agencies”, recalls the director of the Emerging Viruses Unit. Traces of this can be found, for example, in a study on the subject published in the journal Nature from September 2020.

After more than a year of administration of vaccines and nearly five billion people immunized, nothing supports this hypothesis today. Quite the contrary. Works described as “very serious” by Xavier de Lamballerie compared the viral loads of patients infected with Covid-19 according to their vaccination status. For this study, the most complete on this subject, a Singaporean team measured daily the quantity of virus present in the samples of 218 subjects infected with the Delta variant. If, at the time of diagnosis, this value (CT) was the same in the two groups, it fell significantly from the sixth day in the 71 fully vaccinated people. If the facilitative antibody theory were correct, “the viral loads of the vaccinees should be higher than those of the control group”. “The simple observation contradicts this theory, so it certainly cannot be presented as a generalized phenomenon”, concludes our interlocutor.

This absence of evidence is not, however, enough to deter the fervent defenders of this theory, who have published their considerations in an article (not peer-reviewed) widely taken up, and in particular by Didier Raoult. If they believe that the balance between facilitating and neutralizing antibodies in vaccinated people was in favor of neutralization for the original strain of Covid-19 as well as for the Alpha and Beta variants, they now accuse Omicron of affecting “considerably” this balance “facilitating antibody favor”.

Remarks considered with circumspection by the scientific community and that nothing concrete comes to support for the moment. “The analysis of the mechanisms that modulate the epidemiology of the disease deserves all our attention, of course, but we cannot be content with speculation: we must provide convincing scientific evidence”, summarizes our interlocutor. Before emphasizing, moreover, for those who think that the phenomenon only applies to vaccinees infected with the Omicron variant, that a new study carried out by scientific teams in Geneva (in the process of being published) reports, both for the Delta variant and the Omicron variant, that viral loads are lower in vaccinated and infected patients than in unvaccinated infected patients. At this stage, “absolutely no scientific data” has therefore been published in favor of a facilitating antibody mechanism.

Especially since, even at the theoretical level, the defenders of this thesis have still not advanced “how this mechanism could work with Covid-19”, notes Xavier de Lamballerie. Same observation on the side of virologist and epidemiologist Scott Halstead. The one who is still one of the pioneers of this theory of facilitating antibodies in dengue fever, concluded, on December 15, 2020, “that differences in clinical, epidemiological and pathological characteristics” between the two diseases suggest that ADE “does not contribute to the severity of natural human coronavirus infections”. In summary, today there is no fact or scientific article in favor of this theory. “Nobody comes to bring even the beginning of proof. It is, for the moment, the interstellar vacuum”, laughs Xavier de Lamballerie.

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