How concrete are vaccine efficacy claims by Pfizer, Moderna, Gamaleya

Three vaccine candidates have declared the interim results of their phase III trials so far. All of them have claimed more than 90 per cent efficacy by assessing the smaller data. Of all the three, Pfizer and BioNTech's vaccine candidate, BNT162b2, has shown the highest efficacy of 95 per cent.

Story: Mudit Kapoor

Design: Mohsin Shaikh

The high efficacy claims of these companies are, however,  based on a very small number of people analysed to see interim efficacy. In the case of Pfizer and BioNTech, 170 participants (highest amongst the three) were analysed, followed by Moderna (95) and Russia's Gamalaya that analysed the efficacy of Sputnik V vaccine on just 20 participants suffering from COVID-19.

The efficacy results were interim and based on a relatively smaller set of participants, and the final efficacy will be determined only after the complete phase III trials results are announced. For the phase III trials, Pfizer and BioNTech have enrolled maximum 43,538 participants, followed by Gamalaya (40,000) and Moderna (30,000).

The temperature at which the vaccines are stored will play the most critical role in their mass distribution. Those requiring lower temperature will bear higher cost on account of storage and logistics. Not all healthcare institutions across the world are equipped with the infrastructure to store a vaccine at -70 degree Celsius.

Of these three vaccine candidates -- assuming that their vaccines get the requisite approval --  Pfizer and BioNTech may have the edge over the others. Pfizer has claimed the highest production capacity at 1,800 million doses, followed by Moderna with 950 million and Gamalaya at 400 million doses.

To develop a vaccine at such a high speed and accuracy requires a lot of funding. More than $10 billion of funding has been pumped in for R&D of vaccines in phase III trials, as per the info available with Air Infinity. Pfizer has received the highest funding of $2.69 billion, followed by Moderna with $1.5 billion and Gamalaya ($400 million).

These COVID-19 vaccines may require two doses per person within a gap of a few days to show full results. At $10 for two doses, Gamalaya's Sputnik V is expected to be the cheapest among the three. Moderna's mRNA-1273 will be the most expensive, with a price tag of between $50 to 74.