Pfizer ends Covid-19 trial with 95 per cent efficacy; MHRA calls results 'very encouraging'

Pfizer Inc said today that final results from the late-stage trial of its Covid-19 vaccine showed it was 95 per cent effective, adding it had the required two-months of safety data and would apply for emergency US authorization within days.

The final analysis comes just one week after initial results from the trial showed the vaccine was more than 90 per cent effective. Moderna Inc on Monday released preliminary data for its vaccine, showing 94.5 per cent effectiveness.

Data demonstrates that the vaccine was well tolerated across all populations with over 43,000 participants enrolled with no serious safety concerns observed. The only Grade III adverse event greater than or equal to 2 per cent in frequency was fatigue at 3.8 per cent and headache at 2 per cent.

Very encouraging: MHRA

Meanwhile, reacting to the update, UK's medicines regulator said the final late-stage trial results from Pfizer and BioNTech's Covid-19 vaccine candidate were very encouraging, adding it would need to see the full data before making an assessment of the shot.

"The results reported by Pfizer today are very encouraging and add to their announcement from last week," June Raine, chief executive of the Medicines and Healthcare products Regulatory Agency (MHRA), said in a statement, which did not give a precise timeframe for UK regulatory approval.

"We look forward to receiving the full results of the trials as soon as possible, after which we will rigorously assess the evidence of safety and effectiveness of the vaccine."

News is Phase III trial is over

Elsewhere in the academic world, Enrico Bucci, biologist and adjunct professor at Temple University in Philadelphia, said: "Don't get distracted: the news is not 95 per cent protection, safety or effectiveness. For that we wait for the data. The news is that the Phase III trial is over.

"A first in the history of mankind: less than a year from the sequence of the virus to the large-scale clinical trial of a vaccine, moreover based on a whole new technique.

"Today is a special day".

Stephen Evans, professor of pharmacoepidemiology at London School of Hygiene & Tropical Medicine said: "This ... is very good news indeed. There are now rather more data accrued with, it is said, no serious side effects.

"It seems there is some evidence that in older adults...there is also very good efficacy with minimal side effects. This is again very good news, not just for this vaccine, but as it also makes it more likely that other vaccines will also be reasonably effective in older adults."

Trudie Lang, director of the Global Health Network at Oxford University, said: "Today’s update from Pfizer provides further encouraging news and more detail on the protection against disease that their vaccine is showing from this definitive phase III trial. The detail on achieving 94 per cent protection in the elderly participants in the trial is particularly excellent news.

"We will need to wait and learn over time how long the protection lasts, and to see whether this vaccine can also prevent transmission – meanwhile, this vaccine does look likely to have a strong role immediately once it is approved in protecting health workers and the vulnerable from disease." (With Reuters)