Researchers discover drug-resistant Covid in Aussie patients

Drug-resistant variants of Covid-19 are developing in Australian patients within days of infection, an alarming new study has found.

A Uni Sydney paper has found Sotrovimab – one of the main medicines we are using to treat Covid – is causing the virus to mutate within days.

Australian patients are developing drug-resistant versions of Covid-19 within days of being infected and there are calls for better surveillance to contain the spread.

One of the main medicines used to combat severe cases of Covid-19 is causing the virus to mutate and there is a risk it could spread in the community.

If this happens, elderly and immunocompromised patients can’t be treated with the drug Sotrovimab.

Sydney University researcher Dr Rebecca Rockett studied 100 Covid patients in health care facilities in the Western Sydney Local Health District in New South Wales during the Delta outbreak between August and November 2021.

For four of the patients given the drug, the virus in their body mutated within six to 13 days and the treatment was no longer effective at containing the infection.

Samples of the mutated virus taken from these patients were able to be grown in a laboratory dish and this proved the new version of the virus was capable of spreading to others.

A Uni Sydney paper has found Sotrovimab – one of the main medicines we are using to treat Covid – is causing the virus to mutate within days.

“The worrying thing is the fact that the virus was still viable and persisting in these patients after they develop the resistance,” Dr Rockett said.

“What we don’t want to see is that someone in the community develops resistance and they can pass that resistance to other people and that makes the drug ineffective, not just for that individual but for who they transmit the virus to,” she said.

Many of the patients in the study were severely immunocompromised and Dr Rockett said one theory about the emergence of the Delta and Omicron variants of the virus was that they developed in such people.

“There are definitely cases in the literature where these patients with really immunocompromised conditions are given a lot of different therapies and could develop a number of mutations that can make the virus less more likely to evade current vaccines and treatment strategies,” she said.

This is a key reason this population of patients should be kept under surveillance, she said.

Sydney University researcher Dr Rebecca Rockett.

To keep control of the virus, doctors must undertake active surveillance of severely ill patients and identify treatment-resistant mutations earlier so they can be contained, she said.

The research team has not conducted experiments to determine whether current Covid-19 vaccines could combat the mutated virus that developed in these patients.

Sotrovimab is one of three key Covid-19 treatments called monoclonal antibodies that doctors were using to stop patients from becoming seriously ill.

These types of treatments are laboratory-made proteins that mimic the immune system’s ability to fight off viruses.

In January, the US FDA revealed that two of these treatments no longer worked against Omicron leaving Sotrovimab as the only weapon in the arsenal.

In another worrying development last month a Colombia University study that is yet to be peer reviewed found the cousin of Omicron – BA. 2 – had developed resistance to Sotrovimab.

This leaves recently approved treatments paxlovid, molnupiravir which are in short supply as the mainstay of treatment.

Pharmaceutical company GSK which makes Sotrovimab said in a statement that theAustralian research was “a very small study with results consistent with our large, randomised, controlled clinical studies which have shown that a small proportion of patients develop on-treatment resistance”.

“Resistance is also seen in studies for other COVID-19 monoclonal antibodies and oral treatments, and relates to how the immune system interacts with the virus,” the company said..

“This report (Rockett et al) does not change the positive benefit-risk of sotrovimab for use in the treatment of mild to moderate COVID-19 in patients at high risk of progression,” GSK said.