Expert Speak Health Express
Published on Nov 11, 2020
Pfizer COVID19 vaccine 90% effective: 5 highlights

For the US, November 9 will have a very long ‘this day in history’ entry. It proved, in a decisive way, that sickness, health and the hard work of scientific rigour have no connection with political rhetoric and  a prime time television schedule. After nine months of utter public health chaos, the US is closer than ever to delivering the jab we’re waiting for. On November 9, barely a week out from the US 2020 election, Pfizer and BioNTech delivered a bombshell announcement that sent a burst of hope rippling through our quarantine bubbles. These companies’ collaborative Covid-19 vaccine has proven to be 90% effective, based on early test results. America’s top infectious diseases expert Dr. Anthony Fauci thinks the 90% bar is “incredible”. In fact, he believes another US company Moderna’s vaccine will also turn up similarly sunny results. Pfizer’s announcement came on a day when the US passed another grim milestone. Confirmed infections in the US eclipsed 10 million, the highest in the world. New cases are running at all-time highs of more than 100,000 per day, a medical expert on President-elect Joe Biden’s team is warning that the US is heading firmly in the direction of 200,000 cases a day. Against that backdrop comes the Pfizer breakthrough.

Below, we bring you 5 highlights from the Pfizer gamechanger, hopefully the first of many successes in a global treasure hunt.

Key dates in the 9 month sprint

March 17: Pfizer and BioNTech announce plans to develop a COVID-19 vaccine using BioNTech's technology platform.

April 29: Testing of four vaccine candidates begins with volunteers in Germany. Five other countries are part of the testing pool.

May 5: Testing expands to include the US.

July 1: One of four vaccine candidates appears to rev up the immune system, is well tolerated.

July 22: Trump administration agrees to buy 100 million vaccine doses, with an option for 500 million more.

July 27: Late-stage testing begins for 30,000 volunteers.

Sept. 8: CEOs of 9 pharma giants, including Pfizer and BioNTech, pledge they will not be rushed by politics or extraneous factors.

Nov. 8: Pfizer receives data from independent trial monitors who analyse test results.

Nov. 9: Pfizer announces the vaccine appears to be about 90% effective, based on 94 infections in a pool of more than 43,000 volunteers. 

90% effectiveness way beyond what scientists expected

Earlier this year, Fauci said he would be happy with a COVID-19 vaccine that was 60% effective. After Pfizer’s latest results, Fauci indicated that the news would have a “major impact on everything we do with respect to COVID.” “Much better than I expected”, is how Ashish K Jha, Dean, Brown School of Public Health, reacted. On a scale of 1-10, we should be “9.5 happy”, Jha said about his enthusiasm levels. Florian Krammer, professor at the microbiology department at Mount Sinai feels the same way. A vaccine trial participant himself, Krammer says “50% protection against severe disease would be positive news. The 90% that they are reporting right now are basically against symptomatic infection. We don't know if you can still get asymptomatically infected. That might matter in the long run to cut down on transmission, but is not required to protect at-risk individuals against severe disease outcomes.” For Dr. Kavita Patel, who served on Barack Obama’s public health team, the 90% number is “remarkable”. Patel and plenty of other doctors say that if results hold, the Pfizer vaccine is on par with the measles shot.

What we don’t know yet

There’s plenty we don’t know. Does the 90% mean we can prevent 90% of fevers, coughs and chills or are we able to prevent 90% of severe disease, hospitalisations and deaths? Dr. Michael Osterholm, one of the members of Biden’s coronavirus task force, uses the parallel of the influenza vaccine to explain the challenges. “We know,” he says, “that among influenza patients, those with severe outcomes are least likely to respond to the vaccine.” We don't know if older people are as well protected as younger populations. What we have is point in time data which does not explain if protection gets diluted over time. Scientists, however, make it clear that unknowns at this stage don’t dent their hopes at all. “Just the fact that a vaccine that is mostly based on inducing neutralizing antibodies protects from symptomatic infection is fantastic. This might mean that many other vaccines are likely to work as well. Moderna's vaccine is almost identical,” Krammer posted on Twitter. Volunteers in Pfizer’s study got a coronavirus test only if they developed symptoms, so we don’t know if vaccinated people could be spreading the virus but without developing symptoms.

Results based on 94 infections, study to run until 164 infections

Pfizer’s 90% effectiveness results have come based on 94 infections so far and the study is set to run until there are 164 infections to evaluate. None of the stakeholders - participants, doctors or Pfizer/ BioNTech - know who gets the real vaccine and who gets a dummy shot. The best news so far -- Pfizer revealed that there have been no serious safety concerns with its vaccine. Scientists are keeping their fingers crossed that this trend stays put. Earlier this year, AstraZeneca and Johnson & Johnson temporarily stopped their studies after reports of ill health among some participants. Between the current moment and applying for emergency use authorization from the US Food and Drug Administration (FDA), Pfizer is waiting to check off three more boxes: Evidence of efficacy in most vaccinated patients, evidence of safety with data from thousands of patients and manufacturing which is consistently at the highest quality standards. The FDA requires that companies track at least half of study volunteers for two months to look for side effects.

What does emergency authorisation mean?

Typically, the US FDA needs what it calls “substantial evidence” on a drug’s safety based on large scale, rigorous studies. During a public health emergency like the one we’re in right now, those standards are lowered enough so that the potential benefits outweigh potential risks. On November 9, 2020, the FDA cleared an experimental drug from Eli Lilly for people 12 years and older with mild or moderate COVID-19 not requiring hospitalization. It's a one-time experimental treatment delivered intravenously. Regeneron Pharmaceuticals has also asked for emergency authorization for an antibody drug, the same one that Donald Trump received when hospitalised with Covid-19. So far, only Gilead Sciences’ Remdesivir has full approval for Covid-19 treatment.

The views expressed above belong to the author(s). ORF research and analyses now available on Telegram! Click here to access our curated content — blogs, longforms and interviews.


Nikhila Natarajan

Nikhila Natarajan

Nikhila Natarajan is Senior Programme Manager for Media and Digital Content with ORF America. Her work focuses on the future of jobs current research in ...

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