By now you’ve probably heard of the coronavirus outbreak that started in Wuhan City, China. The number of cases is rising, up to about 300 with six deaths. Cases have been reported in several more Chinese cities, including Beijing and Shanghai, as well as in Japan, Thailand, and South Korea. There are also reports of a case in Australia and another in the USA. For a quick explainer, check out my post here.
A few people have asked about whether the virus can be treated with Tamiflu and what the prospects of a vaccine are. I’ll start by saying that as this is a ‘new’ virus, there are no proven antiviral treatments or vaccines. At the moment, people who are ill will be being given treatments to help relieve the symptoms of their infection.
But here’s where we’re at with Tamiflu and vaccines.
A quick reminder what Tamiflu is…
Tamiflu is the brand name for an antiviral medicine call Oseltamivir which is used to treat some people infected with the influenza A and B viruses. Oseltamivir is a neuraminidase inhibitor. This means it works by binding to the neuraminidase enzyme the virus uses to release from infected host cells.
The use of Tamiflu for treating influenza is controversial. A 2014 review of the available trial data concluded that oseltamivir doesn’t reduce the number of people hospitalised by influenza or those experiencing complications. Given that the possible side effects of taking the drug include vomiting, diarrhoea, headaches, insomnia, and seizures, the concluded that the risks outweighed the benefits.
So, could Tamiflu be used to treat this outbreak?
It’s unlikely. Back in 2004 Emily Tan and colleagues tested the ability of 19 approved antiviral drugs to stop the related SARS coronavirus (SARS-CoV) from killing infected cells in the lab. One of the drugs they tried was Tamiflu. It had no effect, so I’m guessing that means the coronaviruses don’t use neuraminidase.
They did find some drugs had an effect and these have been given to people infected with the MERS coronavirus (MERS-CoV). But according to the WHO’s latest MERS treatment advice, there is currently no good evidence that they work. That advice was last updated a year ago so things might have changed since then.
What about a vaccine?
In July last year, the Walter Reed Army Institute of Research published the results of a safety trial of a potential DNA vaccine (GLS-5300) against MERS-CoV. The first-in-humans (Phase 1) clinical trial was on 75 healthy adult volunteers. The results show the vaccine was safe and well-tolerated. More than 85% of the volunteers mounted a good immune response. According to the press release, the vaccine has now advanced to a Phase I/IIa trial in South Korea and a Phase II study in the Middle East. Hopefully, these trials will show whether the vaccine can protect people from MERS or not.
Dr Anthony Fauci, the director of the US National Institutes of Allergy and Infectious Diseases (NIAID) is reported to have said the US National Institutes of Health (NIH) is “in the process of taking the first steps towards the development of a vaccine” for the new coronavirus. I imagine they’ll base it off the success of GLS-5300.
It’ll be at least a year before any potential vaccine is ready for Phase 1 safety trials so don’t expect that to be the solution, at least in the short term. Instead, the key to controlling the outbreak will be to stop the virus spreading. That means quickly identifying infected people and isolating them from others while they are infectious.