If any single date can mark the beginning of the end of the COVID-19 pandemic, Monday’s announcement about the trial performance of Pfizer’s vaccine candidate makes Nov. 9 a leading candidate for the honor.
The exceptional, though preliminary, results from Pfizer are only a beginning. But Pfizer’s news came just when we expected the first results of final-stage trials to arrive. Similar good news from other sources is probably not too far behind.
Pfizer, along with its German partner, BioNTech SE, reported that researchers have no serious safety concerns about the vaccine so far. Initial test results suggest the vaccine is more than 90% effective. Though this rate could drop once full results are available, it is well above the 50% efficacy rate that the U.S. Food and Drug Administration requires. If Pfizer secures emergency use authorization – which it says it will seek this month, if pending results are consistent – a regulatory decision could arrive as soon as December, Reuters reported earlier this week.
For obvious reasons, it is not yet clear how long the vaccine can offer protection. Researchers also warn that there is not enough data to know for sure whether it keeps subjects from getting infected or from getting sick – an important distinction for a disease where asymptomatic carriers can infect others. We still don’t know as much as we’d like about how the vaccine performs among high-risk groups. Even with these caveats, though, the news from Pfizer is heartening. And Pfizer doesn’t carry the burden of solving the crisis alone.
Pfizer’s product is just one of 10 vaccines currently in phase 3 trials to determine their effectiveness, according to tracking by the Regulatory Affairs Professionals Society. (One of those is a combined phase 2 and 3 trial that also seeks to establish safety and dosage thresholds.) In comments to leaders of the American Medical Association last weekend, Dr. Anthony Fauci noted that Pfizer and Moderna have fully enrolled their phase 3 trials. (His remarks focused on the six most advanced candidates from Western developers.)
This queues up Moderna as the likely next developer to report its effectiveness findings. Those findings, if satisfactory, should quickly lead to emergency use authorization for an initial rollout to high-priority recipients.
Both the Pfizer and Moderna vaccine candidates use a new technology, messenger RNA, to induce human cells to create a protein that, in turn, triggers an immune response that blocks the new coronavirus. Both vaccines are expected to require two doses spaced several weeks apart. Pfizer’s (and, I expect, Moderna’s) will need special handling to keep it extremely cold at critical points in the production and distribution process. Quickly immunizing hundreds of millions of people with these products, here and abroad, will be no easy task. Pfizer estimates that, if the vaccine is approved, it can roll out enough vaccine for 25 million people this year and 650 million more in 2021 – a good start, but not nearly enough to end the pandemic alone.
Other candidate vaccines currently in trials were created with different and better-established technologies. They may have different profiles for the number of initial doses required to provide protection; the degree of immunity they generate; the duration of that immunity before recipients require a booster (if the virus remains prevalent enough to warrant ongoing prevention efforts); and the frequency, nature and severity of any side effects.
Defeating the pandemic will require a series of logical, predictable steps. A vaccine must be developed and tested. Then it needs to be manufactured, at vast scale and acceptable cost. Then manufacturers have to distribute it to providers who can administer it. Then the population – or at least a very large swath of it – must agree to take the vaccine, possibly multiple times. Finally, if the virus is not effectively eradicated, we must maintain broad immunization for an extended period.
Epidemiologists and infectious disease experts, including Fauci, provide their most useful insight in the earliest stages of this process. Their advice can help us to control the disease, and to mitigate its human and economic costs before we achieve wide immunity. But once regulators approve vaccines for general use, managing the disease becomes a challenge of manufacturing, transportation, supply chain management and clinical practice. Laboratory science and statistical analysis will have done their part.
In this country, the job of getting one or more vaccines to the public – and getting the public to rapidly accept them – will fall mainly to the incoming Biden administration, along with state governments and the wider medical community. The same hurdles will confront every country around the globe. The pandemic’s national and global impact will end sooner or later. Whether “sooner” or “later” will depend on how well the process is managed and how well it is balanced with other necessary activities of daily life. But one way or another, the pandemic’s end is definitely beginning.