Vaccine developers have been racing against time to find a vaccine that offers immunity against the coronavirus disease (Covid-19). Oxford University announced Monday that its viral disease vaccine was up to 90% effective in preventing infections, Pfizer Inc. applied for an emergency use authorization in the US for its vaccine that showed efficacy. up 995% last Friday, Moderna said its vaccine was 94.5% effective, even as Hyderabad-based Dr Reddy’s Laboratories prepared to begin the final leg of Russia’s Sputnik V in India this week. In parallel, the main treatment protocols are being revised following the results of several global trials that cleared the air on which Covid-19 therapies work better than others.
Most Covid-19 treatments fall into three broad categories: antivirals that prevent the virus from multiplying, immunomodulators that regulate the immune response, and combinations that use multiple mechanisms of action.
Antiviral remdesivir
The antiviral remdesivir was suspended from the World Health Organization prequalification list that developing countries use as a reference for procurement. The suspension followed the health agency’s guidance on Friday against the use of remdesivir in hospitalized patients, regardless of the severity of the disease, after an international guideline development group found no evidence that the drug improves rates of survival, reduce the need for mechanical ventilation, or increase recovery and other patient outcomes. However, the group recognized that more research was needed and supported continued enrollment in trials evaluating remdesivir.
“The WHO guideline group is separate from the Solidarity Trials group, as it reviews all the evidence, including the WHO trial. They concluded that there is no evidence of benefit from (remdesivir) in any group of hospitalized patients and that the available evidence is inadequate if there is a benefit in non-hospitalized patients. As such, corticosteroids are the only class of drugs with a demonstrated benefit in reducing deaths in hospitalized patients. The search for other effective treatment modalities continues, ”said Dr. K Srinath Reddy, President of the Public Health Foundation of India.
Aspirin and other blood thinners.
On the bright side, the ubiquitous pain reliever and blood thinner aspirin was added to the UK’s COVID-19 Randomized Therapy (RECOVERY) trial in early November. “Coagulation is a big problem [in Covid-19]. Aspirin is a cheap and widely available drug that, if it works, would be a huge boost, “said Peter Horby, chair of the RECOVERY trial and professor of emerging infectious diseases and global health at the University of Oxford. House of Commons committees in the United Kingdom.
“Were [also] seeing better use of blood thinners – heparin and others – to prevent clotting, and one might anticipate that the introduction of dexamethasone has had an impact as well. That would be something that would lower mortality rates, ”Horby said.
Monoclonal antibodies
The US Food and Drug Administration this month issued an emergency use authorization for investigational monoclonal antibody therapy bamlanivimab for the treatment of mild to moderate Covid-19 in adult and pediatric patients 12 years of age. or more who weigh at least 40 kg who are at high risk of progressing to serious illness and / or hospitalization. Bamlanivimab is not authorized for hospitalized patients or those requiring oxygen therapy, as it may worsen clinical results.
Monoclonal antibodies are proteins made in the laboratory that mimic the immune system’s ability to fight harmful antigens, such as viruses and bacteria. Bamlanivimab is directed against the spike protein of Sars-CoV-2, the virus that causes COvid-19, and works by preventing the virus from entering human cells.
The US National Institute of Allergy and Infectious Diseases high-effect ACTIV-5 trial also began trials of the monoclonal antibodies risankizumab and lenzilumab last month to see if they helped hospitalized patients recover faster.
Some essays fell short. In October, Eli Lilly and Regeneron Pharmaceuticals suspended their monoclonal antibody trials in hospitalized patients due to lack of efficacy and potential safety concerns.
Monoclonal antibodies are approved for Covid-19 treatment in India. “Monoclonal antibodies have some role in the early stages of the disease, but not in patients receiving oxygen or ventilation. Since they have a limited role in mild disease, and we know that a large number of patients recover on their own, they may not benefit as much, ”said Dr. Randeep Guleria, Director of the Indian Institute of Medical Sciences. (AIIMS) in Delhi at HT Leadership Summit on Thursday. “We also have to consider if we will have enough doses to offer everyone, if the cost can be covered since they are expensive and if they will be needed once the vaccines arrive,” Guleria said.
Antiparasitic Ivermectin
Studies have shown that the widely available and affordable drug ivermectin, which is used to treat parasitic infections, has antiviral action against Sars-CoV-2. The use of ivermectin at doses ranging from 200 to 1200 mcg / kg of body weight, over a period of three to seven days, shows promise in relieving symptoms and reducing viral load.
Two studies of ivermectin alone or in combination with doxycycline found that ivermectin-doxycycline combination therapy had better success in symptomatic relief, shortened the duration of recovery, reduced adverse effects, and better patient compliance compared to the combination. of hydroxychloroquine-azithromycin in mild to moderate cases of Covid-19 disease. A retrospective study of 280 patients treated with ivermectin against standard of care found fewer deaths in the ivermectin group.
In India, ivermectin is part of at least five ongoing trials, according to the Clinical Trials Registry India, and its benefits are under review.
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