COVID-19: treatments that have their limitations

More than two years after the start of the COVID-19 pandemic, the medicine cabinet now has multiple treatments, but using these pills and injections has several limitations.

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Though it’s declining in most countries, COVID-19 hasn’t gone away, and alongside vaccines, medicines can make a difference for those most at risk.

These treatments, preventative and curative, affect people who have had little or no effect from the vaccine (immunocompromised, etc.) or who are at high risk of severe forms and death, including the elderly.

But for the time being, “these powerful drugs are underused, as evidenced by the number of deaths,” Antoine Flahault, director of the Institute of Global Health and professor at the Geneva Medical School, told AFP.

“The main obstacle remains logistics,” he said. “Those affected must think of a PCR test in the event of symptoms or contact hazards, the attending physician must think of prescribing the appropriate medication, the pharmacy has it available in the short time required, the hospital can admit and treat patients” for medication, that are administered in the hospital.

The first category of treatment, antiviral pills, act directly on the virus to prevent it from multiplying.

The most advanced against COVID is Pfizer’s Paxlovid. The World Health Organization recommended a week ago that it be preferred over other treatments, including Merck’s less-potent competitor pill, molnupiravir.

And China gave Paxlovid its conditional green light in mid-February. Good news for Pfizer, which aims to produce 120 million doses this year and already made $72 million last year from a much smaller batch.

But right now, doctors are having trouble prescribing these pills. In France, where Paxlovid is the only approved antiviral, 3,500 out of 100,000 treatments administered in the first trimester were prescribed. In order to continue using it, the authorities want to facilitate its prescription.

Likewise, Joe Biden’s administration in the United States has taken measures for the accessibility and recognition of anti-COVID pills. And Vice President Kamala Harris, who tested positive for COVID on Tuesday, is taking the Pfizer pills.

Still, several brakes are raised by specialists. First, the race against time to administer them: ideally less than five days after the onset of symptoms, confirmed by a test.

Some drugs, starting with Paxlovid, are also “sensitive to use” due to “many interactions with other drugs”, Antoine Flahault specifies.

Another caveat: Certain variants, like Omicron, can reduce potency.

The second main category, monoclonal antibodies, must be administered in the hospital by infusion or injection. They can reduce the risk of hospitalization and death by up to 80%.

These treatments, which target only part of the virus, are used in two ways, depending on the drug chosen. They are either used preventively in people who cannot be vaccinated, or they are given to hospitalized patients to prevent their COVID from becoming complications.

The most important are Evusheld from the Swedish-British AstraZeneca and Ronapreve from the Swiss Roche, both of which are used preventively, the second also curatively. Xevudy from the British GlaxoSmithKline and the American biotech Vir are added as remedies.

Again, the deadlines for administration are tight.

And even more so than the pills, some of these biodrugs are losing their potency over the variants.

“The monoclonal antibodies active against the delta variant are no longer active against Omicron-BA.1, the one that remained active against BA.1 is no longer active against BA.2,” a difficult pace for research and prescribing firmly Antoine Flahault.

If Evusheld still seems to protect against Omicron, a higher starting dose is sometimes recommended to compensate for the lower effectiveness. Ronapreve is almost abandoned in several countries in view of the complete loss of neutralizing activity.

As with vaccines, access to anti-COVID drugs remains very unequal between rich and poor countries. Repeal of patents has been discussed here again, with some progress.

In the fall of 2021, Pfizer and Merck announced licensing agreements under the UN umbrella that allow a cheaper generic version of their pills to be manufactured. In mid-March, agreements were signed with 35 generic drug manufacturers in Europe, Asia, Central and Latin America to manufacture and supply Paxlovid to 95 poor countries.

But the WHO said last Friday “very concerned” that less affluent countries are still struggling to access Paxlovid. She “strongly recommended” that Pfizer go further with more transparent pricing and contracts and an expanded licensing base to allow more generics to produce the drug.

NGOs are still fighting. “When new treatments emerge, it will be just inhumane if they are not available in resource-constrained settings simply because they are patented and too expensive,” warned Marcio da Fonseca, adviser to MSF’s Access to Medicines campaign, in early 2022. . .

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