Pfizer’s COVID-19 Vaccine
It’s been a big week for COVID news! In one corner, the northern hemisphere is entering flu season. So researchers are trying to figure out more about how these two diseases interact. And among other things, they’re finding some early evidence that maybe a flu shot could protect you against both?
Then, in the other corner, there’s been a whole lot of vaccine news from companies like Pfizer, Moderna, and more.
So, let’s dive in. As far as the flu and COVID goes, we do have documented cases of people getting both viruses at once. But there’s a lot we don’t know — including how common this is going to be.
But! If there’s any good news, it’s that some preliminary research is starting to suggest fascinating, and encouraging things about the flu vaccine. We already knew flu shots have a huge impact on flu outbreaks.
Like, the US Centers for Disease Control estimate that they prevented 7.52 million infections, over 100 thousand hospitalizations, and 6300 deaths in the US during the last flu season alone. And that’s because the vaccine teaches the body to specifically spot and eliminate multiple flu strains. But that’s not all it does.
It also seems that some versions of the flu vaccine may ramp up your nonspecific immune defenses, a phenomenon called trained immunity. It seems like exposure to a pathogen even the harmless versions in a flu vaccine can ready the body’s front-line immune cells. These may essentially become “primed” to react more aggressively in the presence of danger.
And those faster, stronger reactions may help rally the immune system to fend off a second invader, even if it’s completely different—like the virus behind COVID-19.
A July preprint may even show this trained immunity in action. Preprints are scientific papers that haven’t been reviewed by independent experts yet, so our understanding of their results might change.
But since COVID is so new, they’re all we’ve got to go on in a lot of cases. In this one from July, researchers analyzed over 92,000 confirmed COVID-19 cases in Brazil, and they discovered that receiving a recent flu vaccine was connected to fewer deaths and less severe infection overall.
This isn’t the only preprint suggesting that populations with good flu shot coverage have fewer cases and less severe COVID-19 infections. But like I said, this is only a preliminary study and a flu shot is no substitute for a proper COVID vaccine.
But as folks in the northern hemisphere head into flu season, it might at least be a silver lining. And speaking of vaccines: In the last week, multiple companies and organizations have come out with early results about their vaccines from Pfizer and Moderna, to groups from Russia and China.
Each group is saying that their vaccines are doing really well, according to early results. But we’re just going to focus on the Pfizer announcement for now, because that’s where we’ve been getting the most questions, and where we’ve had the most time to like, take in and synthesize information.
Pfizer Phase 3 Trial
On November 9th, Pfizer and their partner BioNTech announced some early phase 3 trial results, courtesy of an independent data safety and monitoring board.
According to their press release, getting two doses of their COVID-19 vaccine three weeks apart cut symptomatic COVID-19 cases in the trial population by more than 90%. Which sounds amazing! But these are also really early results. They aren’t even published in a preprint, so experts haven’t been able to look at the study data.
Also, that 90% figure is based on the first 94 infections that occurred within a month of the participants’ first injection of either the vaccine or of a placebo. So, that efficacy number may change as more data comes in.
And of course, there are still a lot of unknowns, like whether the vaccine stops people from catching the disease or from being contagious, or just prevents infections from developing symptoms.
So, this is extremely encouraging but also very preliminary. And there’s an even bigger point here, too: even if this vaccine is as effective as it sounds, getting it to everyone probably won’t happen quickly or easily. That’s because this is a brand new type of vaccine that uses RNA to essentially teach cells to spot the virus.
And it’s super fragile and needs to be kept very cold like minus 70 degrees Celsius. For comparison, freezers in large hospitals are usually around minus 2 to minus 8 degrees celsius.
So, some experts have warned that no one has the capacity to do this kind of distribution on a wide-scale yet. And of course, this may be especially a big issue in rural areas and low- and middle-income countries.
Now, not all COVID vaccines in development require these kinds of extreme temperatures.
So maybe this won’t be a problem we need to overcome. In the meantime, this is definitely a reminder that making a working COVID vaccine is just the start of things.