Pfizer vs Moderna vs AstraZeneca! Whose efficacy to trust?
New vaccines are rarely certified for efficacy above 90 per cent. Their efficacy improves as millions are vaccinated over decades. In fact, most vaccines get certified in the 40-60 per cent efficacy band
- Nov 27, 2020,
- Updated Nov 27, 2020 9:02 PM IST
A sense of frustration is developing in the medical world over lack of uniformity in clinical trials of COVID-19 vaccine makers, which has resulted in rather implausible claims. Top vaccine makers Pfizer, Moderna have claimed efficacy of over 90 per cent. AstraZeneca, which is developing the vaccine with Oxford University, has made it worse by releasing multiple data points for the efficacy of its vaccine. Oxford-AstraZeneca's vaccine is the same vaccine that the Serum Institute is producing in India, and it's most likely to be the vaccine that most Indians will eventually get.
New vaccines are rarely certified for efficacy above 90 per cent. Their efficacy improves as millions are vaccinated over tens of years. In fact, most vaccines get certified in the 40-60 per cent efficacy band. Even a 70 per cent efficacy is considered excellent in the world of vaccines. The world's most powerful vaccine -- Measles -- has nearly 60 years of science and millions of vaccinations backing it to be called 94-95 per cent efficacious.
But vaccine makers are currently flashing high per centage figures because they have carried out tests on extremely small number of people. Pfizer's 'final efficacy analysis' involved only 170 patients, while Moderna had 95. AstraZeneca tested its vaccine on 131 patients. Once these vaccines get tested on thousands, the efficacy is expected to correct to a more reasonable figure.
A sense of frustration is developing in the medical world over lack of uniformity in clinical trials of COVID-19 vaccine makers, which has resulted in rather implausible claims. Top vaccine makers Pfizer, Moderna have claimed efficacy of over 90 per cent. AstraZeneca, which is developing the vaccine with Oxford University, has made it worse by releasing multiple data points for the efficacy of its vaccine. Oxford-AstraZeneca's vaccine is the same vaccine that the Serum Institute is producing in India, and it's most likely to be the vaccine that most Indians will eventually get.
New vaccines are rarely certified for efficacy above 90 per cent. Their efficacy improves as millions are vaccinated over tens of years. In fact, most vaccines get certified in the 40-60 per cent efficacy band. Even a 70 per cent efficacy is considered excellent in the world of vaccines. The world's most powerful vaccine -- Measles -- has nearly 60 years of science and millions of vaccinations backing it to be called 94-95 per cent efficacious.
But vaccine makers are currently flashing high per centage figures because they have carried out tests on extremely small number of people. Pfizer's 'final efficacy analysis' involved only 170 patients, while Moderna had 95. AstraZeneca tested its vaccine on 131 patients. Once these vaccines get tested on thousands, the efficacy is expected to correct to a more reasonable figure.