As the coronavirus pandemic spreads at unprecedented rates, invading the lungs of people of all ages, ethnicities and medical histories, more companies are ratcheting up their efforts to fight the disease with accelerated schedules for creating new vaccines.
In normal circumstances, vaccine development would take about 10 years. But the pharmaceutical industry is racing to compress this timeline with the support of non-profit organisations, government agencies and regulatory authorities. In just a few months, more than two dozen companies have announced promising vaccine programmes, speeding through the early stages of testing unlike ever before.
On Wednesday, Novavax, a Maryland-based biotech company, said its vaccine candidate had stimulated a powerful immune response in lab and animal experiments, producing antibodies that could fight off coronavirus. The vaccine, called NVX-CoV2373, is set to begin human trials in Australia in mid-May.
While a final product that would be widely available is still a year or more away, the Novavax effort is one of many ready to test in people.
A vaccine made by biotech company Moderna is already in a clinical trial, which started on March 15th. Another one, developed by Inovio Pharmaceuticals, was injected into the first adult volunteers on Monday. The healthcare giant Johnson & Johnson expects to start clinical trials in September and has received a nearly $500 million partnership via a division of the US Department of Health and Human Services.
Experimental vaccines developed by researchers at the University of Pittsburgh and Baylor College of Medicine are also waiting for permission from the Food and Drug Administration to begin testing in people.
"We're all trying to do something which we have almost no precedents for, which is accelerating a vaccine in the middle of a pandemic," said Dr Peter Hotez, co-director of the Texas Children's Hospital Center for Vaccine Development at Baylor College of Medicine.
There is no proven treatment or vaccine yet against Covid-19, the illness caused by coronavirus. A vaccine would be the best way to stop further spread of coronavirus because it enhances the immune system’s natural defences. Of course, many companies are also struggling with ways to partner manufacturing ventures to produce enough vaccine so that it would be widely available.
Immune system
White blood cells that act like scouts for the immune system are constantly looking for things that shouldn’t be there. Vaccines train these cells to recognise invading viruses before an infection actually occurs. That way, when coronavirus particles do enter the body, the system is prepared to produce antibodies to neutralise the virus.
More than one million people around the world have already been sickened by coronavirus. For public health experts and those on the front lines, a vaccine can’t come soon enough.
"If you could only have a vaccine, just imagine – you could walk out your door, confident that you were not going to get sick," said Dr Gregory Glenn, president for research and development at Novavax. "Because of that, everyone is very motivated and working to move things quickly."
The team at Novavax is no stranger to the effort that goes into making vaccines. It had worked on experimental vaccines for both Sars and Mers, which are closely related to the new coronavirus. The company also has vaccines for the seasonal flu and respiratory syncytial virus, which causes colds, in the last stages of clinical trials.
When Chinese scientists posted the genetic sequence of the new coronavirus in January, researchers at Novavax immediately started working on recombinant technology to make a synthetic version of the virus. Researchers used a baculovirus to carry bits of genetic material from coronavirus into cells. Baculoviruses typically infect insects, so they cannot replicate and cause illness in humans.
“We never use the real virus,” Glenn said. “But we can fool the immune system to think it’s been attacked.”
By combining the recombinant vaccine with an adjuvant, or substance that increases immune stimulation, Novavax was able to achieve a high “neutralisation titer” in pre-clinical tests – a measure of the protective antibodies that can block the virus.
The company hopes to see a similar effect after giving more than 130 healthy adults two doses of the vaccine. Results of the trial, which will be conducted in Australia, are expected around July.
Moderna and Inovio are pioneering a different approach to their vaccines.
Moderna uses RNA technology, while Inovio has developed DNA technology to package the genetic code of coronavirus spike proteins, which make up the crown around the virus and help it latch onto cells. This approach has the advantage of being able to move to trials faster than vaccines that require the production of viral proteins or a weakened version of the actual virus to induce an immune response. But the technology is still unproven. There are no approved RNA or DNA vaccines for any disease.
Hotez’s team and Johnson & Johnson, on the other hand, are relying on technology that is more similar to Novavax’s approach because it has been used successfully to create other vaccines in the past, including one for Ebola that has been registered in Europe and used in the recent epidemic in the Democratic Republic of Congo.
Some countries already have the manufacturing capabilities that will be needed to scale up vaccine production and keep costs low if everything goes well.
“It’s not very sexy, but it’s a reliable approach. We know that it works,” Hotez said.
For now, the first stage of clinical trials for each potential coronavirus vaccine must focus on how safe or toxic the vaccine may be at different dose levels. Researchers will carefully collect the medical histories of volunteers participating in the trials and track their antibody levels, liver enzymes and other indicators of emerging side effects.
One concern is that the vaccines may inadvertently cause a phenomenon known as disease enhancement, in which vaccinated people develop more severe inflammation and disease than those who have never been vaccinated. Studies of early Sars and Mers vaccines noted this troublesome complication in some animal models.
"If everything looks good and the vaccine appears to be safe, then we'll go on to trials with much bigger numbers and look at the vaccine efficacy," said Dr John Ervin, who is leading the Inovio clinical trial in Kansas city, Missouri.
In parallel, companies are planning to continue further animal testing, as well as investing in manufacturing capacity both in the US and abroad. They will need millions of doses for additional clinical trials and even more if a vaccine eventually goes to market.
Companies also have to be prepared for the possibility that some candidates will fizzle out or that demand for a vaccine will decrease by the time one is ready for widespread use. But industry experts are not waiting for this to happen.
“The virus is racing through crowded urban areas and slums in certain countries. How do you do social distancing in those places? You don’t,” Hotez said. “We are building out a road map for how we work as a country for the next two or three years. That’s roughly the timeframe that we saw for the 1918 flu pandemic and that’s probably likely for Covid-19.” – New York Times 2020
