How has Australia responded to the COVID-19 pandemic and the delta variant, and how is it positioned to deal with the pandemic’s evolving challenges? To find out, GLG recently held a remote roundtable with two public health experts: Dr. Stephen Ostroff, a longtime senior official at the U.S. Centers for Disease Control and Prevention and Food and Drug Administration, and Dr. Kathryn Weston, a professor at the University of Wollongong in Australia and a researcher specializing in the public health aspects of infectious disease and its history. Their discussion, edited for space and clarity, follows.
Dr. Weston: The pandemic has revealed how difficult it can be to encourage everyone to get vaccinated. Do you have any thoughts on how Australia might have increased the effectiveness of its vaccination efforts?
Dr. Ostroff: Australia has worked extraordinarily hard over the past year and a half to protect its citizenry by trying to keep the virus from reaching your shores. That position is possible, of course, because Australia is isolated, and entry can be vigorously controlled. But that’s only a first step, and it implies having a successor plan so that citizens can continue to be protected without maintaining isolation. That approach is vaccination, which Australia has pursued vigorously.
Unfortunately, the road to vaccination has been bumpy due to some early vaccine bets on the part of the government that didn’t pan out, difficulty in acquiring adequate doses of some vaccines, and concerns about their use. Fortunately, the pace of vaccination has increased significantly, especially among the most vulnerable populations. Yet the world’s experience shows there is no silver bullet to widespread vaccination. The strategies that have worked best involve lots and lots of encouragement.
Dr. Weston: When do you think we will reach herd immunity in Australia so that we may be able to reopen the country?
Dr. Ostroff: When we talk about herd immunity, especially in the face of the highly transmissible delta variant, we’re really talking about having about 90% of the population no longer being able to meaningfully spread the virus, and that will involve vaccinating children. One of the truly breathtaking aspects of the current major vaccines is that they not only protect you from getting sick but also do a really marvelous job of preventing you from picking up the virus without symptoms, which is what we refer to as sterilizing immunity. Unfortunately, that sterilizing immunity seems to be slipping, which means the virus can continue to circulate even in the face of very high levels of immunity. As a result, the Australian isolation approach would need to continue if officials want to limit circulation of the virus.
Dr. Weston: You mentioned that sterilizing immunity seems to be slipping, which raises the issue of booster shots. What’s your view on them?
Dr. Ostroff: Boosters are contentious. If you had a choice, you’d want to direct the vaccine to unvaccinated individuals first because they’re the ones who are going to develop severe disease, end up hospitalized, and have fatal outcomes. But, as expected when the vaccines were introduced, we’ve begun to see waning immunity among the vaccinated. The data, in particular from Israel, are quite compelling that boosters are very effective. So, it’s clear they have an important role in protecting the vulnerable and everyone else. Many of us will have boosters in our future, and it will be important for Australia to make sure that people are up to date with their vaccinations and boosters, so immunity doesn’t wane.
Dr. Weston: I guess that means it’s difficult to come up with an answer to when we should reopen the country.
Dr. Ostroff: It’s a tough call. At some point, when a high enough proportion of the population is vaccinated and COVID and the delta variant become a relatively milder disease for most of the population, the disease will become something flu-like and the borders can reopen. I think an important tipping point will be reached when we can vaccinate children.
Dr. Weston: As we’re getting boosters and making ourselves safer, what’s our responsibility to ensure equity across the globe in fighting this disease?
Dr. Ostroff: Quite frankly, it’s a tragedy to see 75% or 80% levels of vaccination in many of the advanced countries when in parts of Africa less than 4% of the population has gotten a dose. It’s a terrible situation. The virus will continue to seek out places with low vaccination rates and wreak havoc. And as long as large swaths of the planet are not vaccinated, new variants will continue to emerge, which means an endless chase to fight off the disease. That said, the argument that nobody should get a booster dose until other parts of the world are vaccinated is based on a faulty premise. It’s not either-or. We ought to be able to do both. And one of the ways we can do both is to continue to have other vaccines come through the pipeline.
Dr. Weston: What are the prospects for more vaccines?
Dr. Ostroff: It’s interesting to note that since the beginning of the pandemic, there have been about 280 or 290 candidate vaccines that have been explored around the world by academic centers, governments, and industry. More than 100 of them have made their way into clinical trials. That’s really quite impressive. A few of them have demonstrated fantastic performance, like the vaccine from Novavax, which uses a completely different mechanism — protein subunits — and looked great in clinical trials in the UK, the United States, and South Africa. So where is it? I’m baffled as to why it’s not out there. Later in the year, we will have a vaccine from GSK and Sanofi that uses similar mechanisms to the Novavax vaccine. Those companies can produce a lot of vaccines, as can companies in China and other parts of Asia. We ought to be able to solve the vaccine shortage problem quickly, which should make some individuals who have been reticent about taking a vaccine more comfortable.
Dr. Weston: What about new treatments and therapeutics? They seem to be overlooked.
Dr. Ostroff: They have. Since we’ve largely put our eggs in the vaccine basket, the progress on therapeutics has not been as dramatic. Up to this point, we’ve largely had three therapeutic approaches.
The first is remdesivir, which destroys the virus by interrupting its ability to replicate its genetic material. It works great if administered relatively early in the course of illness; it does not work well later.
The second approach involves using monoclonal antibodies, which passively administers the antibodies instead of having your body stimulate the production of those antibodies through a vaccine. This approach appears to be successful, although there’ve been some hiccups in terms of resistance to some of the variants. Antibodies also appear to be successful in preventing people from developing severe illness if administered early enough, as well as in preventing COVID after exposure to it. We refer to this approach as pre- and post-exposure prophylaxis, and it has been a viable alternative for immunocompromised people who may not mount good responses to the vaccine. Unfortunately, antibodies are difficult and very expensive to make and must be administered as an infusion. There have been some studies recently about having them administered via injection. Results look promising, but the injections involve multiple jabs in the abdomen, which I don’t think many people would take well to.
A third approach is using steroids for those who have developed very severe disease. Administering dexamethasone has reduced the likelihood of having a fatal outcome.
Some interesting work is going on in two other categories. The one that many people are excited about is a product being developed by Merck called molnupiravir, which uses the same mechanism as remdesivir but is administered orally. It would be a game changer. Other companies are working on protease inhibitors, which are a main category of therapeutics for HIV. The inhibitors are designed to prevent the formation of one of the enzymes the virus needs to replicate itself. The main protease inhibitor attracting attention is being developed by Pfizer.
Over the next 6 to 12 months, we should see some new therapeutics that could transform the way we view the disease.
About Stephen Ostroff
Stephen Ostroff, MD, is the former Deputy Commissioner for Foods and Veterinary Medicine at the U.S. Food and Drug Administration. Dr. Ostroff has also served as the acting FDA Commissioner on two occasions, from April 2015 to late February 2016 and again from January to May 2017. He served as the FDA’s Chief Scientist starting in February 2014. Dr. Ostroff joined the FDA in 2013 as Chief Medical Officer in the Center for Food Safety and Applied Nutrition and Senior Public Health Advisor to the FDA’s Office of Foods and Veterinary Medicine. Prior to that, he served as Deputy Director of the National Center for Infectious Diseases at the Centers for Disease Control and Prevention. Dr. Ostroff was also the Director of the Bureau of Epidemiology and Acting Physician General for the Commonwealth of Pennsylvania and has consulted internationally on public health projects in South Asia and Latin America. He graduated from the University of Pennsylvania School of Medicine in 1981 and completed residencies in internal medicine at the University of Colorado Health Sciences Center and preventive medicine at the CDC.
About Kathryn Weston
Associate Professor Kathryn Weston comes from a strong research background in immunology and cell biology, having worked at Harvard Medical School in the U.S. and at the University of Technology, Sydney where she gained her PhD in the area of immunotoxicology and cell biology. Prior to her academic appointment at the University of Wollongong, she worked as a senior infectious diseases and vaccination public health officer with NSW Health in western Sydney, with experience in disaster management, epidemiology, and health protection. Now retired, she remains an active researcher in public health aspects of infectious disease and its history, and the history of prison medicine.
This healthcare policy article is adapted from the GLG Remote Roundtable “Australia’s Response to COVID-19.” If you would like access to events like this or would like to speak with healthcare policy experts like Stephen Ostroff, Kathryn Weston, or any of our approximately 1 million industry experts, contact us.