On Monday, Pfizer Inc announced in a press release that its COVID-19 vaccine, co-developed with its German partner BioNTech, has demonstrated a 90% efficacy rate in preliminary results from its Phase 3 clinical trials. While the results are based on early and incomplete test results, they do nonetheless provide a huge burst of optimism to a world in desperate need of a solution to bring this devastating pandemic under control.
Dr. Bill Gruber, Pfizer’s Senior Vice-President of Clinical Development, expressed his optimism regarding the vaccine in an interview with the Associated Press:
“We’re in a position potentially to be able to offer some hope…we’re very encouraged.” 2
Once it has the necessary safety information in hand which is expected later this month, Pfizer will be able to apply to the US Food and Drug Administration for emergency-use approval.
As of today, here are some of the things we know, and some of the things we don’t know about the vaccine:
1. Early Results from the Clinical Trial Show 90% Effectiveness
Back in July, Pfizer and BioNTech began a late-stage clinical trial related to the coronavirus vaccine involving 43,538 participants.
In the trial, half of the people received two doses of the vaccine while the other half received a placebo. The companies then had to wait to see if the vaccine offered the recipients any protection from COVID-19.
After a statistically significant number of trial participants became infected with the virus, researchers were then able to compare COVID-19 infection rates between the groups.
The trial’s initial analysis resulted in the vaccine being shown to be at least 90% effective in preventing a viral infection 28 days after beginning the two-dose schedule. Meaning that the majority of the illnesses that were confirmed resulted from those in the placebo group. Another reason for optimism was that no serious safety issues were reported.
The excellent results were surprising to many as for months most scientists have cautioned that any COVID-19 vaccine may only be as effective as flu vaccines which are roughly 50% effective and necessitate annual immunizations. In fact, earlier this year, Dr. Anthony Fauci, who is the US government’s top infectious disease expert, said he would be happy with a vaccine which was 60% effective.
Given his statement earlier in the year it wasn’t all that surprisingly that Fauci lauded the results showing potential 90% effectiveness as “just extraordinary” while adding, “Not very many people expected it would be as high as that.” 2
2. Distribution of the Vaccine Will Be a Herculean Challenge
As promising as Monday’s news is, there are still many logistical challenges that must be overcome, which include:6
- The vaccine co-developed by Pfizer and BioNTech, if approved, will be the most fragile one used in the US as it needs to be stored at roughly minus 75 degrees Celsius (or minus 103 degrees Fahrenheit) plus or minus 15 degrees.
- This creates many challenges including the fact that doctor’s offices, pharmacies and state labs do not have the ultra-low temperature freezers that go that low as it is roughly 50 degrees colder than any of the currently used vaccines in the US.
- Alternatively, the CDC suggests maintaining the vaccine using dry ice, which they haven’t had to do previously.
- The vaccines are shipped to sites in a box that Pfizer developed which they call a “thermal shipper”.
- Clinics who receive the shipper can use it to store the vaccines until it is time to thaw, dilute and then inject them into patients’ arms.
- There is a caveat: As soon as the sites receive the vaccine, they must replenish the dry ice, and if they don’t use the vaccine in the following five days, they need to replenish it again, and then again in another five days.
- The vaccine is able to be refrigerated, however if it is not used within five days it needs to be thrown away.
- Oh, and check this out – when they are ready to administer it, nurses have to dilute the vaccine, creating five doses with one vial. And those five shots need to be given within six hours, otherwise the vaccines need to be thrown out.
- And just to add a bit more complexity to the situation, this whole process needs to be repeated for each patient. Remember, the vaccine is administered in two doses, given three weeks apart.
3. How Many Doses Will Be Available?
According to the Pfizer press release:
“Along with the efficacy data generated from the clinical trial, Pfizer and BioNTech are working to prepare the necessary safety and manufacturing data to submit to the FDA to demonstrate the safety and quality of the vaccine product produced.
Based on current projections we expect to produce globally up to 50 million vaccine doses in 2020 and up to 1.3 billion doses in 2021.” 1
Therefore, as two of the Pfizer-BioNTech doses are needed for each person, 25 million people will be able to be vaccinated in 2020 with another 650 million people in 2021.
The first round of vaccines available to the public are expected to go to healthcare and front-line workers, as well as those people who are more vulnerable to COVID-19 such as the elderly or those with risk factors such as obesity or diabetes.
4. The Vaccine Was Not Part of “Operation Warp Speed”
Unlike other companies such as Moderna and AstroZeneca, Pfizer did not accept any federal funding to develop or manufacture the vaccine.
In fact, the company has tried to distance itself from President Trump and Operation Warp Speed as Senior Vice President and the head of vaccine research and development at Pfizer, Kathrin Jansen said in an interview on Sunday:
“We were never part of the Warp Speed…we have never taken any money from the US government, or from anyone.” 5
The company however did release a statement on Monday saying that it did sign a contract in July to provide the United States with 100 million doses for $1.95, assuming that the vaccine was approved by the FDA.
5. There Are Things We Still Don’t Know…
While the news on Monday was indeed positive, there are still several things we don’t know regarding the vaccine, including:
- How long the effects of the vaccine last and whether or not it will protect elderly people as well as the young.
- Additionally, participants in the study only received a COVID-19 test if they developed symptoms. This means that we still don’t know if those who are vaccinated are able to be infected yet show no symptoms and spread the virus unknowingly.
- No matter what the issue is, there is always an opposing view. In this case, one of the opposing views comes from a consumer advocacy group called “Public Citizen” who deemed the release of the preliminary and incomplete data “bad science”. They cautioned that any optimism over the result “must be tempered” until they are reviewed by both the FDA and its independent experts.
- The study has yet to be approved by the FDA, but Pfizer and BioNTech believe they are getting close:
“Pfizer and BioNTech are continuing to accumulate safety data and currently estimate that a median of two months of safety data following the second (and final) dose of the vaccine candidate – the amount of safety data specified by the FDA in its guidance for potential Emergency Use Authorization – will be available by the third week of November.” 1
- Although the early results do offer some compelling evidence as to the effectiveness of the vaccine, they still do not tell us the effectiveness with certainty. Clinical trials, by nature, are not designed to do that. What they do is permit scientists to make statistics-based estimates known as efficacy. A vaccine’s effectiveness can only be confidently determined once millions of people receive it. But the experts do say that the early data shows that the effectiveness should be extremely high.
So, while the news of the Pfizer-BioNTech vaccine was met with a lot of optimism, as you can see there are still some hurdles that need to be overcome and questions that need to be answered.
Hopefully, those hurdles are all cleared, and the questions answered so that the vaccine can be given with confidence…Community Confidence!