Pfizer clinical trial for Covid-19 vaccine lacks sufficient data on Asians: Report

Data for this particular phase revealed that only a meagre 4.3% of the participants tested were of Asian ethnicity

On Friday, the United States Food and Drug Administration (USFDA) gave the go-ahead for the emergency roll out for the Pfizer-BioNTech mRNA Covid-19 vaccine, making the USA the the sixth country to approve the two-dose vaccine, after the United Kingdom, Bahrain, Israel, Canada, and Mexico.

Read | Explainer | Covid-19 vaccine: What is Emergency Use Authorisation?

In Pfizer's phase 3 clinical trials, the vaccine delivered an efficacy of 95%, but as shown by Mint, lacked sufficient data on Asians, let alone Indians. Data for this particular phase revealed that only a meager 4.3% of the participants tested were of Asian ethnicity, with the majority of the persons tested, 83%, were White.

While it posed an overall efficacy of 95%, that figure was 74% for Asians, making it a cause to worry. This revelation comes at a time when Pfizer, which is yet to get a nod of approval from the Drug Controller General of India, has sought a waiver for conducting clinical trials.

Anant Bhan, global health, bioethics, and health policy researcher, highlighted that positive results of clinical trials from western countries do not translate in the same manner in lower and middle-income countries. He said that it is always better to have 'local data'.

Davinder Gill, a Massachusetts-based vaccine expert, stressed that companies must initiate clinical trials in a heterogeneous country like India. He was also wary of the efficacy that the Pfizer vaccine showed among Asians.

Suneela Garg, Director of the community medicine department at Maulana Azad College, however, believed that the lower efficacy rate did not pose a threat. She pointed out that an efficacy rate of over 60% is 'good enough'. But she also added that it is important to note that the mRNA Covid-19 has more side effects than the flu vaccine.

Pfizer has so far conducted a majority of its 150 trials in the United States, while 22 were conducted abroad in countries like Germany, Brazil, Argentina, South Africa, and Turkey. The company maintains that the participants who were chosen hail from diverse ethnic backgrounds, with global diversity at 42%, and Unites States participants at 30%.

There are presently seven vaccines undergoing trials in India. The most notable of them are AstraZeneca's Covishield, which is being tested by the Serum Institute of India (SII), and Bharat Biotech, which is developing an inactivated virion jab called 'Covaxin' alongside the state-run Indian Council for Medical Research (ICMR).