What do you see in terms of a realistic Covid-19 vaccine timeline, and what would a vaccine offer in terms of protection/immunity? How can it possibly be safe? I assume it’s being rushed through the process – is that right?
Nick Kanaan, Ph.D.:
I would defer to the experts on a timeline, and would reiterate what Dr. Fauci and others with appropriate expertise are saying – 1-1.5 years. Of course, we all want one as soon as possible!
The effectiveness of the vaccine is hard to predict with certainty. Some anti-viral vaccines have completely eradicated their disease, but others (like vaccines against the common flu) are only somewhat effective due to natural changes in the virus over time. Optimistically, a COVID-19 vaccine that completely eradicates the disease would be the jackpot. In lieu of that result, I would consider it a significant win for all of us if a vaccine could minimize the effects of the virus to a level that dramatically reduces the mortality rate.
How — and When — Can the Coronavirus Vaccine Become a Reality?
Below are excerpts from ProPublica’s article, written by Caroline Chen and posted on June 17, 2020.
Let me tell you this up front: If you’re imagining there’ll be one golden day when a vaccine is approved and the pandemic will be over — Finally! We can all crowd into one another’s living rooms and resume choir practice again — I’m afraid it won’t be quite like that. But it will be the beginning of the end.
On a vaccine’s effectiveness:
One lucky break COVID-19 vaccine developers have had is that this coronavirus hasn’t mutated in any significant way so far, including, crucially, the part that is most visible to the immune system, that spike protein. So long as that remains true, the vaccine they make should match up with the virus that our bodies will encounter in the real world, meaning it’ll likely work as intended. Given the stability seen so far in the coronavirus’s genetic sequence, “I am hopeful that when we do develop a vaccine, it will provide long-term protection,” Kartsonis said.
On vaccine safety:
When experimental vaccines are tested, they usually go through three phases of clinical trials. The first phase is the smallest and focuses on safety, making sure that the product doesn’t have any dangerous health effects. The second is a little larger, continuing to gather safety data while testing if the vaccine can induce an immune response, producing antibodies in participants. The third trial is the largest, and it needs to be big enough to confirm that the vaccine is actually effective in the real world.
“If the data were clear that in 20,000 people it appears to be safe and highly efficacious, then you should get the vaccine, because if you’re choosing not to get a vaccine, you’re choosing to risk getting a natural infection, which could be fatal.”
On current trials:
Moderna Therapeutics is currently expected to be the first U.S. manufacturer to start a phase 3 trial. Candidates by AstraZeneca and Johnson & Johnson will follow, according to The Wall Street Journal. Moderna’s trial is planned to begin in July and will enroll about 30,000 participants.
The speed of the phase 3 trials depends on the rate of infection wherever people are enrolled. If there is a huge outbreak going on, people in the placebo group will get sick at a high rate, and the trial may be over in a matter of a few months. If infection rates are very low, however, the trial could drag on for months on end. Moderna hasn’t announced its trial sites yet, but it will have sites “well dispersed” in the U.S. and is considering international trials as well, according to a spokesman.
On availability:
Typically, drugmakers will manufacture only enough doses for clinical trials and make sure the trials are successful before starting mass production. Manufacturing at risk means that developers will instead begin mass production at the same time as clinical trials, which means that if a vaccine fails in human trials, they’ll have to throw away all the product they’ve made, wasting money and materials. But if a product is successful, it means that the minute its trial is completed, there’ll be millions of doses ready to go.
Manufacturing at a massive scale is no simple task. “If we’re going to immunize 300 million people in the U.S. — we don’t even do that with the flu vaccine every year — we need a lot of glass vials, we have to make sure we have printing supplies and paper to make the labels and package inserts, we need stoppers for the vials, and they all need to be made to a very high standard. All this in addition to the raw materials to the vaccine itself,” Schaffner said.
Pfizer and its partner, German company BioNTech, are planning to have a few million doses ready by the end of the year, and hundreds of millions of doses available in 2021, even though the first of their four vaccine candidates just began its first early-stage human trials in May.
There will need to be a prioritization, with the vaccine given first to those who need it most: essential workers and the elderly.
Distribution is going to be a massive challenge. “There’s a need to have in place a mechanism to ensure people who should get the vaccine get it,” Dr. Walter Orenstein, associate director of Emory University’s vaccine center, said. “We won’t have 8 billion vaccines. So who should get priority, and how should it get delivered? We will need to remove barriers to access, including cost and distance.”
