Various countries are now making an effort to create vaccines in an apparent race against time.
But when, exactly, would these vaccines be made available?
Trialsite News, which tracks and covers around the globe, said in its 19 April, 2020 report that China’s CanSino Biologics recently is advancing its SARS-CoV-2 vaccine to a Phase II clinical trial. This essentially makes CanSino Biologic’s vaccine candidate a top contender in the global race.
John’s Hopkins University, in an article Vaccine won’t appear overnight written by Supriya Munshaw, recounts the step-by-step process of vaccine development and creation, with each vaccine candidate having to go through phases. After Phase II, vaccines will still have to undergo Phase III clinical trials. That is why the 18 month estimate is not too far-fetched. A widely available vaccine most likely isn’t going to reach the public by this year and the earliest would be middle to late 2021.
“Challenge” studies – or studies that involve exposure to human subjects – are currently conducted to fast-track vaccines in the light of the CoviD-19 Pandemic. These are modified clinical trials in which the testing for immunogenicity in animals and humans are done simultaneously instead of sequentially. Then they rapidly advance its effective doses in large scale Phase II and III trials using low risk healthy volunteers.
These challenge studies are controversial and it has ethical implications due to the nature of how it they are done. It is arguably less safe than the usual sequential pattern of vaccine development, which is why the World Health Organization has come up with very strict guidelines for the selection and informed consent of individuals who volunteer.
Weighing in, the high risk / faster turnaround time of developing vaccines this way is perhaps a better alternative than to keep the slow yet sure tediousness of vaccine development because every day that passes is a risk of another life lost waiting for a cure, and it will not just be one life dying daily because world counts are clocking in thousands of deaths per day.
The Dangers of Haste
Trump administration’s bid to deliver a CoviD-19 vaccine faster than any previous vaccine is both turning heads and raising eyebrows with a major new investment that promises to shave weeks off its already ambitious timeline.
John Cohen, in an article in ScienceMag.org, quotes pediatrician and vaccine researcher Paul Offit who expressed doubts that rolling out an October-November deadline for mass vaccinations for this vaccine proposal is highly unlikely.
The vaccine in question is the one being made by Oxford University (second one on the list here.)
A study ChAdOx1 nCoV-19 vaccination prevents SARS-CoV-2 pneumonia in rhesus macaques published in bioRxiv suggested that the Oxford vaccine prevents severe lung disease caused by SARS-CoV-2 but lacks evidence if it prevents infection – a CoviD-19 vaccine should have capabilities of preventing both or at least have sterilizing immunity to prevent infection, which highly suggest that the Oxford vaccine need more time and that too much fast tracking could fuel vaccine suspicion and undermine the efforts of other vaccine’s being worked on.
Currently the most comprehensive and promising results yet from a human trial of a CoviD-19 vaccine candidate come from China’s Cansino Biologics (see part 1 for details). A study published in the Lancet states that Humoral responses against SARS-CoV-2 peaked at day 28 post-vaccination in healthy adults, and rapid specific T-cell responses were noted from day 14 post-vaccination. Long story short: it suggests a potential for providing immunity.
Even then, the experts behind this vaccine are cautious and claimed the final results will be evaluated in six months or more before proceeding on drastic implementations like the Oxford vaccine.
Sooner or later our salvation will come, that is certain, and that is what we should keep holding on to. But even with all the aid, (or lack thereof) surviving until then is pretty much left to us at the end of the day. So stay safe, and stay informed.