On Monday morning, When pharmaceutical company Pfizer representatives said its Covid-19 vaccine appears to be more than 90 percent effective, stocks rose, White House officials rushed to (falsely) to take out loans, and there were sighs on the internet Relief. “Dear world. We have a vaccine! The best news since January 10, ”tweeted Florian Krammer, virologist and vaccine doctor at the Mount Sinai School of Medicine (who also happens to be participating in the Pfizer Covid-19 vaccine study).
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However, a press release from a pharmaceutical company stating that a vaccine works is very different from the actual effects of a vaccine that works. Pfizer and its German vaccine partner BioNTech have not yet published any data from their Phase III study. This week’s results are based on the study’s first interim analysis, conducted by an external panel of experts after 94 of the 43,538 participants contracted the coronavirus. This analysis suggests that most of the people who got sick were given a placebo instead of the vaccine. But it doesn’t say much beyond that. (More on why this matters later.)
And from a logistical point of view, a lot still has to happen before people who are not major can roll up their sleeves. Pfizer researchers are now collecting safety follow-up data for at least two months. If these results don’t raise red flags, the company could apply to the U.S. Food and Drug Administration for emergency approval. Only then could executives begin handing out the 50 million or so doses they are expected to take by the end of the year. This process is made difficult by the fact that until it can be shot in the arm of a human, Pfizer’s vaccine must be stored at temperatures down to -80 degrees Fahrenheit, which is much colder than the standard vaccine cold chain. Completion of immunization also requires two doses three weeks apart. Oh yes, and states that you are currently trying to do all the other things you need to do to prepare for such a complicated vaccination surge – phasing out vaccines, setting up digital registers, deciding who gets vaccination priority – without doing extra money for the bother.
There are a lot of reservations. Still, there is reason for hope. If the results are correct, a 90 percent effective Covid-19 vaccine has far exceeded the limits of effectiveness set by the FDA. That level of protection would be achieved with the measles shot, one of the most effective vaccines ever developed.
Introducing an effective vaccine to fight SARS-CoV-2 less than a year after the novel coronavirus emerged would break every record vaccine manufacturers have ever set. “History isn’t even the right word,” says Larry Corey of the Vaccines and Infectious Diseases Division at the Fred Hutchinson Cancer Center. Corey, a renowned virologist, has been looking for a vaccine against the AIDS-causing virus for the past three decades. He’s never seen a vaccination for a new bug in less than five years, let alone one. “It’s never happened, never, not even close,” he says. “It’s just an amazing feat of science.”
And perhaps even more monumental is the type of vaccine that Pfizer and BioNTech are bringing across the finish line. The active ingredient in their shot is mRNA – mobile genetic code strings that contain the blueprints for proteins. Cells use mRNA to bring these specifications from tough DNA storage to their protein factories. The mRNA in the vaccine from Pfizer and BioNTech drives all cells it reaches to carry out a coronavirus spike building program. The viral proteins these cells produce cannot infect other cells, but they are foreign enough to trigger the body’s defense systems. They also look like the real virus to train the immune system to detect SARS-CoV-2 in case its owner comes across the infectious virus in the future. So far, this technology has never been approved for use in humans. A successful mRNA vaccine will not only be a triumph over the new coronavirus, it will also be a huge advancement for the science of vaccine manufacturing.