There’s new hope for a coronavirus vaccine, but let’s not celebrate too quickly

Let’s allow ourselves a moment of elation at the news that the first coronavirus vaccine has not only been developed in record time, but appears to be highly effective.

Woot, woot!

Now that we’ve gotten that out of our system, let’s remember that while the pharmaceutical giant Pfizer has declared that its vaccine is “90 per cent effective,” the details are scant and the caveats are many.

Determining how well a vaccine works is difficult at the best of times, especially for respiratory viruses. Doing so quickly, with a novel coronavirus and an innovative technology many times more so.

The results that are making headlines around the world are preliminary, and they have yet to be published in a peer-reviewed scientific journal.

While Pfizer and its partner BioNTech are making obvious efforts to be transparent (drug studies are usually highly secretive), we should always be skeptical of science-by-press-release.

Here’s what we know: After the vaccine candidate – formal name BNT162b2 – showed promise in laboratory, animal and human tests, and did not seem to be harmful in early safety trials, it moved to a Phase 3 clinical trial.

The company enrolled 43,538 volunteers who were randomly assigned to receive the vaccine or a placebo; 38,955 of them received a second dose. Clinical trial participants were monitored and tested until there were a sufficient number of infections to analyze. (The study design is controversial, for technical reasons not worth getting into other than to say it’s unusual.)

Among the tens of thousands of volunteers, 94 infections have been confirmed. Pfizer did not say specifically how many of the infected had received the vaccine, but the 90 per cent effectiveness claim suggests it was eight or nine.

There is also more that we don’t know about the vaccine than we do know.

It appears to prevent some infections among people vaccinated, but does it mean they no longer carry the virus? Some of those vaccinated were still infected, but did they have less severe illness? Does the immunity created by the vaccine last?

These are huge unknowns.

While Pfizer announced its preliminary results, it has not yet requested regulatory approval from the U.S. Food and Drug Administration. It won’t do so for at least two more weeks; first, it has to wait until there are at least 164 COVID-19 cases among study participants to analyze.

Then the review process, no matter how expedited, will take time. It’s worth noting that the method used to create immunity, messenger-RNA technology, is new. No mRNA drug or vaccine has ever been approved.

Even if the vaccine gets through the process with flying colours, it needs to be manufactured and distributed.

Pfizer says it can produce 50 million doses in 2020 and another 1.3 billion in 2021. (Canada has a contract for “millions of doses,” but details are scant.)

Distribution is yet another matter. This high-tech vaccine has to be stored at minus 70 C, and transported in special coolers. It also requires two doses, making it more bothersome and expensive to administer widely.

In other words, getting the vaccine into people’s arms will be a Herculean task.

Most governments have said pandemic vaccines will be provided to the public at no cost. But it will not be free. The United States has signed a contract with Pfizer to purchase 100 million doses for US$1.95-billion, roughly US$20 a dose.

All of this is without even mentioning the ethical challenges, such as deciding who will be vaccinated first. In Canada, the National Advisory Committee on Immunization has already weighed in on this question, identifying priority groups, such as frail elders, front-line medical staff, essential workers such as grocery store staff, and residents of remote First Nations.

We desperately need a vaccine – or six – if we hope to quash the pandemic.

But there are many, many challenges ahead.

Nevertheless, this is positive news.

The Pfizer vaccine is far more effective in preliminary results than anyone expected. That bodes well for other vaccine candidates.

According to the New York Times vaccine tracker, there are 52 vaccines in clinical trials in humans, including 11 in large-scale Phase 3 trials in humans.

Some of those will require only one dose, and won’t need to be kept in ultracold freezers; others may cost less.

Whether Pfizer ultimately prevails in the global vaccine race doesn’t matter.

The take-home message is that there will likely be effective coronavirus vaccines in the coming months. There will be no silver bullet, but there will be bullets.

That’s the most hopeful news we’ve had since this pandemic began. Instead of revelling in it, let’s ramp up our planning so we can deliver on the promise as quickly and effectively as possible.

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