Coronavirus vaccines can 'backfire' if rushed, skipping safety tests not an option: Experts
As many as 35 potential vaccines against the new coronavirus are in the pipeline. After one of them entered clinical trials last month, it brought in cheers. At the same time, atleast four other potential vaccines are expected to make it to clinical trials if they pass tests for safety and efficacy in animals.
The world is staring at a grim situation, the virus has made inroads into every part of the world, infecting 1,275,542 people and killing 69,487 people. And in the coming days, it is only expected to get worse. Given the circumstances, there are a lot of hopes pinned on vaccines, but it could take 18 months, even if everything goes according to plan. During these months, vaccines are thoroughly evaluated, making sure they are effective and safe.
And for those wanting to speed up the process, experts have a word of advice: do not rush them. If researchers are not allowed to evaluate them extensively, vaccines could backfire and malfunction, risking the lives of many.
"A lot of people have asked me what's the harm in just skipping safety and efficacy vaccine trials and getting vaccine candidates out to the general public right away," tweeted Dr Angela Rasmussen, a virologist at Columbia University, adding that there are other examples of vaccine candidates failing spectacularly and increasing disease risk.
This comes after President Donald Trump pledged to do away with red-tapism and get vaccines out as soon as possible. "Do me a favor, speed it up, speed it up," Trump told pharmaceutical executives.
“You really have to test a vaccine carefully and not just roll it out because people are clamoring for it with an epidemic underway," Dr Marc Lipsitch, an epidemiologist at the Harvard Chan School of Public Health told PNAS.
Wrong vaccines make the disease more severe and extensive testing can avoid that
Thoroughly investigating vaccines help scientists weed out the ones that do not work. These tests also eliminate vaccines that pose risks.
For example, in the 1960s, careful tests showed that certain potential vaccines against dengue and SARS were dangerous. Instead of helping the injected animals and people, it worsened their disease.
The worsening of the disease is the work of a malfunctioning vaccine. They backfire by turning your biggest weapon against invading microorganisms: the immune system against you while helping the virus survive.
Another example was the infamous STEP trial. Here, researchers tested a promising vaccine against HIV and stopped the trial after seeing discouraging results. "It failed, as it increased the risk of HIV infection," says Dr Rasmussen.
"We don't know much about SARSCoV2 and it will be critical to make sure that any vaccine will be safe and effective," she added.
Vaccine development is an elaborate process. It begins with preclinical studies -- where researchers test their candidates in animals and other lab tests. If successful, they move to clinical studies which are divided into four phases.
Vaccines in the pipeline
Most recently, US scientists developed a potential coronavirus vaccine which helped mice generate antibodies capable of fighting off the disease.
Their candidate vaccine -- called PittCoVacc -- looks like a patch attached with 400 tiny microneedles. When placed on the skin, the microneedles inject a coronavirus protein called spike protein into the mice's body. The mice's body, in turn, generates antibodies that seek and attack the foreign protein. Antibodies tend to have a good memory: remembering earlier attacks, it can inflict fatal blows on the new coronavirus if it were to enter the body again.
After completing animal studies, scientists have set their eyes on starting phase I human clinical trials in the next few months.
“Testing in patients would typically require at least a year and probably longer. This particular situation is different from anything we’ve ever seen, so we don’t know how long the clinical development process will take. Recently announced revisions to the normal processes suggest we may be able to advance this faster," co-senior author Dr/ Louis Falo, at Pitt’s School of Medicine and UPMC, said in a statement.
Meanwhile, in Australia, researchers are testing another potential vaccine in ferrets. And a team from the University of Oxford will test the same vaccine on humans --501 of them-- in the next few weeks. The trails will inform scientists on its safety and efficacy.
Earlier, on March 16, the US pharma company named Moderna began its first human trials. A Germany-based company named CureVac is set to begin clinical trials and anther Maryland-based Novavax has announced human tests in spring.
In the coming months, researchers will screen out those that malfunction. "Not all horses that leave the starting gate will finish the race,” says Bruce Gellin, who runs the global immunization program for the Washington DC-based nonprofit, the Sabin Vaccine Institute, told The Guardian.