Game of one-upmanship! Pfizer now says vaccine efficacy 95% - not 90%

In a big boost to Pfizer and BioNTech's vaccine rollout plans, the two companies have found their vaccine candidate - BNT162b2 - to be 95 per cent effective against COVID-19. During its early analysis, the vaccine had shown 90 per cent efficacy but the final analysis involving 170 confirmed cases of COVID-19 showed 95 per cent efficacy, the companies claim. The announcement by Pfizer comes two days after another US pharma company, Moderna Inc, claimed its vaccine was 94.5 per cent effective against COVID-19.

"Primary efficacy analysis demonstrates BNT162b2 to be 95 per cent effective against COVID-19 beginning 28 days after the first dose; 170 confirmed cases of COVID-19 were evaluated, with 162 observed in the placebo group versus 8 in the vaccine group," a Pfizer statement said.

The Pfizer statement said that in a few days, the companies plan to submit a request to the US Food and Drug Administration (USFDA) for an Emergency Use Authorisation (EUA) based on the totality of safety and efficacy data collected, as well as manufacturing data relating to the quality and consistency of the vaccine candidate. "We also plan to submit the efficacy and safety data from the study for peer-review in a scientific journal once analysis of the data is completed," it said. The company said the Phase 3 study of their COVID-19 vaccine candidate met "all primary efficacy endpoints".

The company says efficacy was consistent across age, gender, race and ethnicity demographics. The observed efficacy in adults over 65 years of age was over 94 per cent, claims the company. With these results, Pfizer said the safety data milestone required by US Food and Drug Administration (FDA) for Emergency Use Authorisation (EUA) has been achieved. "Data demonstrate vaccine was well tolerated across all populations with over 43,000 participants enrolled; no serious safety concerns observed; the only Grade 3 adverse event greater than 2 per cent in frequency was fatigue at 3.8 per cent and headache at 2.0 per cent," claims the company.

"The study results mark an important step in this historic eight-month journey to bring forward a vaccine capable of helping to end this devastating pandemic. We continue to move at the speed of science to compile all the data collected thus far and share with regulators around the world," said Dr Albert Bourla, Pfizer Chairman and CEO. "With hundreds of thousands of people around the globe infected every day, we urgently need to get a safe and effective vaccine to the world."

Pfizer and BioNtech will now submit the trial details to the USFDA for emergency use authorisation, and share data with other regulatory agencies around the globe. The companies expect to produce up to 50 million vaccine doses in 2020 globally and up to 1.3 billion doses by 2021-end. "Pfizer is confident in its vast experience, expertise and existing cold-chain infrastructure to distribute the vaccine around the world," the company said. Four of Pfizer's facilities are part of the manufacturing and supply chain - St Louis, MO; Andover, MA; and Kalamazoo, MI in the US; and Puurs in Belgium. BioNTech's German sites will also be leveraged for global supply.

Early trial results show promise

Notably, Pfizer and BioNTech, and Moderna and Russia's Sputnik V are the only vaccines that have claimed over 90 per cent efficacy of their respective candidates so far. While Russia had already rolled out the Sputnik V for the masses in August, the recently announced data results on the efficacy of Moderna, and Pfizer and BioNTech's vaccine raise high hopes.

Like, Pfizer, Moderna's vaccine has shown 94.5 per cent efficacy. Moderna says its COVID-19 vaccine candidate remains stable for 30 days at 2-degree Celsius to 8-degree Celsius, the temperature of a standard home or medical refrigerator.

However, these broad and early efficacy figures may not tell the whole story. The data results are based on a relatively smaller group of participants (170 in case of Pfizer). Moderna's vaccine was analysed based on results of 95 patients, while Sputnik V's efficacy was observed by analysing just 20 participants. Nonetheless, those numbers raised hopes around the world that vaccines could help put an end to the pandemic soon. The efficacy numbers will, however, change as the vaccine trials advance.

Pfizer and BioNTech's COVID-19 trials

The Phase 3 clinical trial of BNT162b2 began on July 27 and has enrolled 43,661 participants to date, 41,135 of whom have received a second dose of the vaccine candidate as of November 13, 2020. Around 42 per cent of global participants and 30 per cent of US participants have racially and ethnically diverse backgrounds, and 41% of global and 45% of US participants are 56-85 years of age.

Also Read: Common people have to wait until 2022 to get coronavirus vaccine shots, says AIIMS chief 

Also read: Pfizer, BioNTech to take vaccine candidate with least side effects to final trials

Also Read: Moderna COVID-19 vaccine 94.5% effective; can be stored in homes, clinics for 30 days

Also Read: Have enough data for first interim analysis of Covid-19 vaccine: Moderna