Researchers in Norway and Estonia found combination of two drugs very useful against SARS-CoV-2. They tested the combination of drugs in culture which proved effective.
On June 16, University of Oxford in the United Kingdom announced the first drug to be useful against COVID-19.
Now researchers at Norway found two more drugs to useful to treat coronavirus. These are anti-viral drugs and have proved to treat infections before.
Scientists from the Norwegian University of Science and Technology in Trondheim and scientists at the University of Tartu in Estonia collaborated to perform this study.
Different cell line from humans and animals were studied. They selected the most infected of the viruses. They found cell line of African green monkeys the most infected.
Cultures of these cells were exposed to SAR-2-CoV-2 and 136 different concentrations of antiviral drugs.
The same team set up a database previously in which those drugs were added which passed clinical safety trials. These drugs were also from the database of broad-spectrum antiviral agents (BSAAs).
The team examined the cultures after 72 hours. In this case, they examined the cultures and checked the remaining cells. The drug with lowest number of remaining infected cells is the most effective one.
Six out of 136 drugs were found effective:
Afterwards, the researchers tried different combinations for better results. Different antiviral drugs are more powerful combination as compared to individual. In addition, developing resistance for viruses against combination is difficult.
Nelfinavir and amodiaquine, which are anti-HIV drug and an anti-malarial drug respectively, formed the best combination.
The interesting thing is that one of the drugs helps protect the host cell while the other destroys the predator, the virus.
The researchers claimed that the combination was effective against all the seven strains of SARS-CoV-2. However, experts are debating on whether SAR-CoV-2 has strains or not.
“This orally available drug combination — nelfinavir-amodiaquine — inhibits the virus infection in cell cultures. It should be tested further in preclinical studies and clinical trials now,” said senior study author Denis Kainov, an associate professor in the Norwegian University of Science and Technology’s Department of Clinical and Molecular Medicine
The researchers then tested efficiency of convalescent blood plasma, or ‘serum’, with the help of doctors at St. Olavs Hospital in Trondheim, Norway.
The blood of the patients recovered from an infection is being used to treat other patients with same infection. Plasma transfusion is a century old method.
According to researches till now, plasma is effective to treat COVID-19 and is safe to use.
Researchers say that the blood of recovered patients contains anti bodies. However, tests have proved that antibodies to virus are present in plasma but not all of them are able to neutralize virus.
For investigation, the researchers used the monkey cells to make a “neutralizing antibody test” for the SAR-CoV-2.
Experts conducted trials by exposing the cells to SAR-CoV-2 virus along with plasma samples. The more recent recovered patient’s plasma was more effective.
After two months of diagnosis of COVID-19 in patient, there were not enough antibodies in the plasma to kill the virus effectively.
Study co-author Svein Arne Nordbø, an associate professor in the Norwegian University of Science and Technology’s Department of Clinical and Molecular Medicine said “this means if you collect blood from patients who have recovered from COVID-19 after 2 months from diagnosis of the disease and transfuse their plasma/serum to severely sick patients, it may not help.”
He also said that doctors should collect plasma immediately after the recovery of the patient. This would be helpful to treat other people.
Antibodies in the blood decrease with time. However, if someone gets coronavirus again, the ‘memory cells’ in immune system start producing new antibodies to fight it. Thus, the virus can’t attack again.
The cells used for the research were monkey cells, not human. But these were the cells which were most affected by the virus.
The drugs proved to be effective in the culture but it is not necessary that it also happen in the organism. There are different conditions in the organism as compared to culture. Most likely, the drugs will prove to be useful for human beings too.
The researchers will further investigate and perform more research on animals along with clinical trials on humans.