WAITING FOR a breakthrough in the fight against covid-19 has been a bit like waiting for a bus to arrive. After a year of watch-checking and neck-craning, two come along at once. Just a week apart, successful results from a pair of vaccines have been reported. An announcement on November 16th, by Moderna, an American biotech firm, followed that of Pfizer and BioNTech on November 9th. Both vaccines will improve humanity’s lot. But there are important differences between the two.
Moderna says that its offering is 94.5% effective. Stockmarkets celebrated, just as they had when Pfizer declared its result. American share indices closed at record highs. Moderna’s estimate of efficacy is based on an interim study of a trial of 30,000 patients—ie, the researchers took a peek at the data gathered in the ongoing trial. They found that 95 participants had caught covid-19, of whom 90 were in the placebo arm and thus had received dummy vaccinations rather than the real thing.
This is just ahead of Pfizer’s efficacy of 90%-plus (although both firms’ estimates are likely to be adjusted when complete data are available). Even if they are adjusted downwards this will not alter the fact that the world now has two highly effective covid-19 vaccines on its hands. (Most observers had not dared hope for a figure above 70%.)
Moreover, the results from Moderna provided more insight into how, and for whom, the vaccine works. There were 11 severe cases of covid-19. All were in the placebo group. It was also clear that the trials in question included participants of a range of ages, including those above 65, and of ethnic backgrounds. This means that the Moderna vaccine looks likely to save lives among groups of people who have been hit disproportionately hard by covid-19. A continuing review of the safety data from the trial has also shown that the vaccine is well tolerated, although one person in ten suffers a day of flu-like symptoms, such as fatigue, muscle and joint pain.
A full comparison of the two vaccines is hard, because so little information is yet available from the trials. There is, though, one factor that already sets the Moderna vaccine apart. It can be kept in a regular fridge at between 2°C and 8°C for 30 days. The Pfizer vaccine, by contrast, needs to be kept ultracold, at -70°C or below. That makes the Moderna vaccine far easier, and cheaper, to distribute.
In the coming months, the demand for vaccines will be such that both firms will sell all they can make. But another factor could eventually come into play: cost. The firms have been cagey about the prices they will charge. The Pfizer and Moderna vaccines are thought to be expensive, at between $40 and $60 for a course of two jabs. A vaccine being developed by AstraZeneca, another pharmaceutical company, is expected to cost only about $6-8 a course. This will matter when doses are distributed by the hundreds of millions, or billions.
AstraZeneca’s vaccine, trials of which are not far behind the other two, could end up being in much wider demand around the world. Although it remains to be seen whether this vaccine works, and works well, the results from the first two are auspicious. AstraZeneca has used a slightly different technology from the other two firms, but the general strategy is the same. This is to introduce the genetic instructions for making the viral spike protein into the body—thus creating an immune response.
It seems likely that Pfizer’s and Moderna’s vaccines will be the first to become more widely available, assuming the firms in question succeed in their efforts to obtain emergency-use authorisation from regulators around the world. It is not clear that AstraZeneca will follow the same route. Mene Pangalos, its head of R&D, told the Greenwich Economic Forum, a conference, last week that the firm might apply for full approval (rather than emergency authorisation) in America, and perhaps in Britain and other parts of Europe too. Countries, too, will need to choose their strategies. For those strapped for cash there will be a trade-off between ordering a smaller number of doses sooner and a larger number later on. The tools the world needs to emerge from the covid-19 pandemic are starting to arrive. That can only be a good thing. Even if they do all arrive at the same time.