Two antiviral pills (Merck molnupiravir and remedesivir), as well as a new intravenous antiviral drug (Pfizer PF-07304814 acting similarly to its new antiviral pill, Paxlovid) are effective against the Omicron variant of the coronavirus, according to with a new laboratory research by scientists in the US and Japan.
However, this is not the case with monoclonal antibodies, which are much less effective against Omicron than previous variants of the coronavirus, with many of them completely losing their ability to neutralize the virus, according to the new study, which they also showed. other research. The new findings show that new monoclonal antibodies need to be developed specifically against Omicron, but the process will take several months, so it is doubtful whether this will help in practice, at least as far as the current pandemic wave is concerned.
The researchers, led by renowned virologist Yoshihiro Kawaoka of the Universities of Wisconsin-Madison and Tokyo, who published the study in the New England Journal of Medicine, said that in addition to laboratory tests, Omicron pills confirmed and in patients, it will be pleasant news. Health authorities in many countries hope that antiviral pills will be widely used to treat Covid-19, reducing the severity of the symptoms and consequently the risk of hospitalization, something that will relieve the stressed health systems. At present, however, the supply of pills is limited.
"The main conclusion is that we have countermeasures against Omicron. This is good news. But these are laboratory studies. "Whether this will 'translate' into humans, we do not know yet," said Dr. Kavaoka.
All available pills and monoclonal antibodies were designed and tested before the advent of Omicron, which differs significantly from previous variants in terms of mutations, with the result that scientists have expressed concerns about whether new drugs are ineffective in the case of the new variant. . Eventually, it seems that this only applies to antibodies, but antiviral pills continue to "work".
This was more or less expected, because Omicron has dozens of different mutations in the spike protein with which the coronavirus enters and infects cells and which is designed to target monoclonal antibodies. Any major changes in this spike, as has happened in Omicron, inevitably make it difficult or impossible to attach monoclonal antibodies to it. Antiviral pills, on the other hand, target not the spike protein, but the molecular mechanism that the virus uses to make copies of itself in human cells. Omicron has few changes in this biological mechanism, so antiviral pills retain the ability to block it.
Pfizer PF-07304814 is not taken orally like Paxlovid, but is given intravenously. But both "target" the same biological mechanism of the coronavirus. The intravenous drug is currently in clinical trials.
Of the monoclonal antibodies tested, only GlaxoSmithKline sotrovimab and AstraZeneca's Evusheld were found to retain some anti-Homicron ability, but at doses three to 100 times higher than those required in previous variants of the virus. Lilly and Regeneron monoclonal antibodies have been shown to be completely ineffective against Omicron in their common dosage.
Link to the scientific publication:
Source: RES-EAP