COVID-19: Vaccines and Better Treatments 'On the Horizon'

Liam Davenport

July 31, 2020

With numerous vaccines against COVID-19 currently in clinical trials, the first successes should be seen around the end of this year, although scaling them up to national and global production will be a challenge, argue leading experts.

Moreover, while numerous treatment strategies for people infected with the virus are also starting to show their worth, more focus will be required on those with more severe disease, while public health efforts should concentrate on modifiable risk factors such as diabetes and obesity.

These conclusions were drawn during a discussion that formed part of the COVID-19 Conference: Sharing the international lessons learned, which was held online by the Royal Society of Medicine (RSM) on July 27.

Vaccines

In a session on future management strategies for COVID-19, Robin Shattock, professor of mucosal infection and immunity, Imperial College London, explained that, in terms of vaccines, "there's lots of encouraging news".

He said that, from a standing start 6 months ago, there are now 24 vaccines currently in clinical evaluation, with "another 160 behind them".

"So that's good news," although "obviously the challenge is to demonstrate whether they work, and that's a numbers game."

It also depends, Prof Shattock added, "whether people are looking for vaccines that prevent disease or vaccines that prevent infection".

Although a vaccine that prevents transmission of COVID-19 is the "ultimate goal", he noted that "whether that will be the first type of vaccine we see past the post...is really an open question and we won't know until we see the data".

He said that the "best scenario" will be if some of the vaccines come through "towards the end of this year and the beginning of next year", after which he expects "more and more".

However, Prof Shattock underlined that the "challenge" is going to be access to the vaccines, "because the rich countries are already trying to advance purchase as many different candidates as they can".

"There's no certainty that any one vaccine approach is going to work," he said, "so if you have a lot of money you're going to spread your bets and buy as many options as possible."

That will "make it really tough for low and middle income countries to get vaccines" in the shorter term.

He continued that the other challenge is "just the sheer volume" of vaccines required.

"Thinking about the UK in the first place, if we want to vaccinate the entire UK population in the first half of next year, that's never been done, so we have to be very creative" about implementing mass vaccination strategies.

When it comes to scaling up those efforts globally for seven billion people, Prof Shattock pointed out that "currently the biggest number of vaccines that are made a year is about half a billion doses of polio vaccine".

"Nobody has made a billion doses of any vaccine globally in any single year."

Treatments

Looking at treatments for patients infected with COVID-19, Professor Roger Kirby, RSM president-elect, and chair of the conference, noted that in-hospital mortality is falling and wondered whether clinicians are "doing better...in terms of caring for our patients with this awful disease".

Dr Andrew Badley, professor of infectious diseases, Mayo Clinic, Rochester, Minnesota, USA, replied that care is "improving over time", for which there are "multiple reasons".

He explained that "we're getting a greater understanding of the disease process, of when and how to intubate, when and how to start anticoagulation [and] when and what drugs to use".

"I'd like to make comparisons between where we are now and 20, 30 years ago when we started the HIV epidemic. It took us several years to get any therapies that had a sense of activity; we've accomplished that now in a couple of months."

Dr Badley also highlighted that drugs such as remdesivir are more widely available, and that clinical trial data on other antiviral agents and immunomodulatory agents is expected soon.

"And then there's a whole new class of drugs that are beginning trials which have different mechanisms of action that I'm very optimistic about."

These include broadly neutralising antibodies, recombinant antibodies, and therapies that target granulocyte-macrophage colony-stimulating factor.

Consequently, he believes that, "when a patient is diagnosed and needs to come into the hospital, our ability to take care of them is better than where it was 2, 3, 4 months ago".

However, Dr Badley underlined that the next step will be not only to know which drugs are active, but "at which stage of disease to use them better".

The trials that have been conducted so far have tended to focus on patients who are "not yet ICU-bound", which is probably "because that's the most common group and a group for which you can show differences".

"As time goes on, we need to stratify where you are in the disease stage, and target therapies to each different stage."

Another important area of research will be the use of combination therapies, Dr Badley said, as "the history of successfully treating viral diseases" such as HIV and hepatitis C, shows "very clearly that multiple therapies are better than one".

He also pointed to recent research published in JAMA indicating that rare loss-of-function variants of X-chromosomal TLR7 may be associated with severe COVID-19 in younger, predominantly male, patients without preexisting medical conditions. A study of four such men suggested that some of these patients may have primary immunodeficiencies that predispose to severe infections.

"I think that's the beginning of what will be a large flood of data that we'll get in the coming months of how genetic host polymorphisms are associated with differential disease outcomes," Dr Badley said, "and I think that is going to be a critical area."

Reducing Risks

In an earlier session, Professor K. Srinath Reddy, president, Public Health Foundation of India, New Delhi, underlined that tackling pandemics such as COVID-19 will require not just novel vaccines and treatments but also a reduction in risk factors for severe disease, such as obesity and diabetes.

He said: "We find that every time there is an epidemical outbreak it is people with comorbities, and the elderly who often have comorbidities, who are the people who are most likely to succumb in terms of mortality or extremely severe illness.

"Therefore for any kind of viral outbreak, as illustrated vividly by COVID, but also applicable to other viral diseases as well, I think the lesson to the health system and the policymakers should be that we need to reduce the burden of diabetes, hypertension, chronic respiratory disease, and obesity, including visceral obesity."

Prof Reddy believes that reducing the burden of these will require both policy and health system level actions.

"The lesson is that we ought to be rebuilding our health systems to take better care, both in terms of prevention as well as early detection and care, of all of these chronic diseases, which set the stage for viral infections to wreak their havoc."

Echoing his comments, Sian Griffiths, emeritus professor at Chinese University of Hong Kong, and visiting professor, Imperial College London, said that this "isn't just about preventing infectious diseases".

"This is about making sure our populations are more robust and able to cope with the disease should they get it. So, less diabetes, less heart disease, particularly in our vulnerable communities."

Prof Griffiths also noted that the "simple messages" around hand washing, face masks, and social distancing need to be at the forefront of our minds.

"If we don't remember that, we're not going to be able to prevent the spread of this disease because, however quickly the vaccines become available, it is...the social and health inequalities that are making this disease much worse in our poorer communities."

The webinar was supported by the Kantor Charitable Foundation.

No conflicts of interest declared.

COVID-19 Conference: Sharing the international lessons learned: Session 4 - Looking forward: research, vaccines and future management strategies. Presented July 27.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....