By Gwynne Dyer
All the usual caveats apply: don’t go out and celebrate, don’t let your guard down, it’s still going to be a long haul. This winter will be “hard”, warned Uğur Şahin, co-founder and
CEO of BioNTech, the German company that announced the first effective Covid-19 vaccine only a week ago. It can’t be rolled out fast enough to reduce infections much in the current wave, he said.
The publication on 16 November of positive results for a second vaccine, this time by the US company Moderna, strengthened the optimism. Clearly, this coronavirus can be beaten, and there are nine more potential Covid vaccines already in third-stage (final) human trials.
But again, the riders: there will be at least half a million more Covid deaths this winter. “What is absolutely essential,” said Şahin, “is that we get a high vaccination rate before autumn/winter next year.” That’s when it could really be over
And yet there is cause to celebrate, because of the eleven vaccine candidates that were already in third-stage trials, both the front-runners are ‘messenger ribonucleic acid’ (mRNA) vaccines, an entirely new approach that allows a much faster response to novel viral infections.
Traditionally, new vaccines took around ten years to be developed, tested and approved for general use. For the new mRNA vaccines, it has been ten months.
RNA carries the genetic instructions from the nucleus of the cell to build whatever protein is needed, and for the past decade researchers have been trying to fabricate ‘messenger’ RNA that could be inserted into human cells. It would then use the cell’s own genetic machinery to make vaccines and other medically useful proteins.
By 2018 several companies had cracked the problem of getting the mRNA past the body’s immune defences, and so they were ready when Chinese scientists posted the RNA sequence of the new coronavirus on the web on 10 January of this year. All they had to do was choose which bit of the coronavirus RNA to use in the vaccine.
Just a harmless segment of the virus’s RNA, copied millions of times by the vaccinated person’s cells, would alert the body’s immune system and train it to destroy any invading coronavirus containing that sequence. (They chose the ‘spike’ the virus uses to attach itself to the human cell.
Several companies had mRNA vaccines ready for testing within two or three months, and the results have been spectacular. BioNTech/Pfizer reported 90% efficacy for its vaccine early this month, and more recently Moderna reported 94.5%.
A third mRNA vaccine now in third-phase trials at Imperial College in London could be even better, because it will be far cheaper than the BioNTech/Pfizer vaccine ($39 for two shots) or the Moderna jab ($74 for 2 shots) if it pans out.
The mRNA technique may mean that future pandemics can be dealt with far more quickly. Just “plug and play ”, as one researcher put it. Pfizer boss Albert Boura went even further: “It’s the greatest medical advance in the past 100 years.”
Well, maybe, though a vote taken today would probably plump for antibiotics instead. But we are only beginning to see the potential of mRNA. There are already trials underway for many other diseases: not just safer, more effective influenza, polio and HIV vaccines, but immunotherapies for cancer, heart disease, cystic fibrosis and other systemic and congenital diseases.
It may not be a miracle, but it will do for now.
