According to the World Health Organisation Europe, some 36 million Europeans – or one in 30 – may have experienced the so-called long COVID so far. Now a major Swedish research study will try to determine if Pfizer’s anti-viral Paxlovid has any effect on patients suffering from long COVID.
Researchers at the Karolinska University Hospital and the medical university The Karolinska Institute, KI are doing a clinical randomised study, and the trial started this summer.
“We will be excited to see the first results at our half-time evaluation later this autumn,” Petter Brodin, a paediatrician and professor in immunology who leads the research project at KI, told Euractiv.
He and the team will have more validated data to present next spring.
Long COVID is a broad diagnosis that covers a range of lasting symptoms – for example, fatigue, fevers, cognitive problems, pain, and cardiovascular complications. Its causes are still being explored.
It is “a glaring blind spot in our knowledge, that urgently needs to be filled,” Hans Kluge, WHO regional director for Europa, said in a speech this summer, where he also stated that estimates now show 36 million people in Europa might have experienced long COVID so far.
Long COVID can lead to serious and chronic health problems, burdening all aspects of people’s lives, including work and productivity, and adding pressure on health systems.
“The uncertainty about this condition highlights the need for an assessment of various aspects of health systems which may not yet be fit for purpose to face the emerging burden from long COVID,” an expert panel on effective ways of investing in health reported last year.
Fighting long COVID with antivirals
Paxlovid (nirmatrelvir and ritonavir) reduces the sars-cov2-virus’s ability to replicate itself in the body. It got approval in Europe last year for treating adults with acute COVID-19 infection. One dose consists of three oral pills.
In Sweden, the antiviral is covered by national subsidies and primarily recommended for risk groups. A possible complication is the interaction with other pharmaceuticals.
Now the drug is being tested off-label in a trial at the Karolinska University Hospital, with 400 participants who have long COVID and “objectively measurable organ damages” after COVID infections, said Petter Brodin. Of the cohort, two-thirds are given the antiviral and one-third a placebo.
The hypothesis is that the Sars cov-2 virus is clinging onto body tissue, plasma and organs. Coronavirus has for example been found in brain tissue and glands.
If the drug is to work for long Covid patients, the residual virus must replicate in the cells. “If the virus just stays still in the body, the treatment won’t work, Petter Brodin explains to Euractiv.
Meanwhile, patient organisations are welcoming the study.
Lisa Norén is a Swedish general practitioner and a spokesperson for the Swedish COVID Association and the network of long COVID-affected doctors –“Physician to physician”.
She developed the long COVID symptoms in April 2020 when she started to experience respiratory distress and chest pains. Before the infection, she had run 20 marathons.
“This is the first time in Sweden that researchers are trying to treat long COVID with a drug rather than by rehabilitation, so it’s very welcomed by us in the patient organisation and the doctor’s network,” she told Euractiv.
Norén is excited about the trial but cautioned that “Paxlovid might not be a remedy for all. Long Covid likely has several different causes that differ between those affected”.
But there is a chance that it might help some patients, primarily those in whom the virus remains present in their organs.
The Stockholm office of the manufacturer Pfizer Sweden closely follows and sponsors the study. Christian Gerdesköld Rappe, a medical expert in the division of infectious diseases products at the Pfizer office, declined to speculate whether Paxlovid may have any effect on those with long COVID.
“But the trial is very exciting, and we are happy to have such a highly considered gang of researchers on-site at the Karolinska Institute to do the study,” he said.