Pharmaceutical companies' predictions about COVID-19 vaccines haven't come true
Video above: Officials concerned over distribution of potential coronavirus vaccine
Over the past six months, pharmaceutical companies have made various predictions about their COVID-19 vaccine timelines that have turned out not to be true.
In one recent example,鈥疨fizer鈥痟as said for weeks鈥痠t鈥痺ould know by the end of October whether its vaccine works. But Tuesday on an investor call, the company's CEO essentially ruled that out.
While at times Pfizer and other companies have couched their statements, other times they have been more definitive about their projections.
Scientists say that should guide us as we move closer to having a vaccine: Don't believe everything you hear because testing and manufacturing vaccines is notoriously unpredictable.
"Unexpected things happen all the time in vaccine development," said Dr. Nelson Michael,鈥痑n Army vaccine specialist who鈥痟as worked on more than 20 vaccine clinical trials.鈥�"There are tons of twists and turns,鈥痑nd it's important to understand that."
While health officials have also made forward-looking statements, they've typically been more vague than pharmaceutical companies.
Last week,鈥疦ational Institutes of Health Director Dr. Francis Collins the National Press Club he鈥痳emains "cautiously鈥痮ptimistic" that the United States could have a COVID-19 vaccine authorized by the end of the year, but warned "it might take longer."
Dr. Paul Offit, a member of the U.S. Food and Drug Administration vaccine advisory committee, said pharmaceutical companies would be wise to stop making forecasts about their timelines.
"Companies should stop making predictions, because nature is very humbling," Offit said.
Claim of a 'near鈥痯erfect' vaccine鈥�
In September, Ugur Sahin, CEO of鈥疊ioNTech, which is鈥痺orking with Pfizer on鈥痠ts coronavirus vaccine,鈥痶old CNN that his company's vaccine is "near perfect."
Scientists shuddered at the thought of describing a vaccine as "near perfect" when it hasn't yet been fully studied in large-scale trials. The鈥疨fizer鈥痸accine, as well as three others, are still in鈥疨hase 3鈥痗linical trials in the United States, and no one knows if they work at all, let alone鈥痶o near perfection.
Vaccines by Pfizer and another pharmaceutical company,鈥疢oderna, utilize鈥痑 new kind of technology鈥痠n鈥痶heir COVID-19 vaccines.
Offit said that alone is reason for caution.
"This virus has been around for less than a year, and it causes a variety of clinical findings that we never would have predicted, and now we're going to counter it with a vaccine that has no commercial experience? How about a little humility here?" said Offit, a member of the FDA's Vaccines and Related Biological Products Advisory Committee.
According to a鈥疊ioNTech鈥痵tatement sent to CNN, Sahin's comment was "based on preliminary antibody and T cell responses and鈥痑鈥痜avorable safety profile observed in the study so far. He also鈥痭oted that there is a need to wait for the efficacy data which is not鈥痑vailable yet."
Pfizer's CEO has made predictions about鈥痺hen it will be clear if a vaccine works or not.
On Sept. 8, Albert鈥疊ourla told the "鈥疶oday" show "we will have an answer by the end of October" whether the vaccine works, adding that "our model, our base case, predicts that we will have an answer in, by the end of October. Of course, this is only a prediction."
On Oct. 16, Bourla made a similar comment鈥痠n an on his company's website, stating that "we may know whether or not our vaccine is effective鈥痓y the end of October."
Video: Fauci: 鈥榊ou cannot abandon public health measures鈥� even with COVID-19 vaccine
But on the investor call Tuesday鈥� just five days before the end of the month 鈥� Bourla said the company hasn't seen its vaccine data yet. Pfizer's first opportunity to see that data will be when 32 people in its trial become sick with COVID-19, and Bourla told investors that this has not yet happened.
Reaching those 32 coronavirus cases will still not give the company the data it needs. An independent panel of experts will need to analyze those cases, and that can take at least a week, Bourla told investors. That means the data couldn't come in October, as Bourla had predicted.
"I don't believe our鈥疌EO鈥痮r we have said that the world should definitely expect an announcement at the end of the month. Rather, it's that there was potential that we would know about efficacy by the end of the month. Nothing has changed," according to a company spokesperson.
Predictions鈥痜rom the University of Oxford for September results鈥�
Pfizer isn't the only company that's made predictions that likely will not or did not come true.
In April, Sarah Gilbert, an Oxford researcher, told in the UK that she was鈥�"80% confident" the vaccine being developed by her team would work, even though at that point Oxford had not even started their Phase 3 clinical .
In May,鈥疌NN asked Oxford researcher Dr.鈥疉drian Hill when the university's trial would end.
"My guess is July would be good. August more likely. Might be September," he said.鈥�"We're aiming for September but hoping to finish before that."
September came and went. Even now,鈥疧xford's Phase 3 trial is still underway.
"We have seen with this pandemic that the spread and transmission rates have fluctuated making them challenging to predict, and important measures to control cases, such as the lockdown by the UK Government, have slowed the transmission rate," an鈥疧xford spokesperson鈥痺rote in an email to CNN. "We have consistently maintained that if transmission remained high, we may get enough data in a couple of months to see if the vaccine works, but if transmission levels drop, this process could take longer."
Viruses and vaccines are unpredictable鈥�
The spread of a virus is unpredictable, and vaccine experts say that's exactly why pharmaceutical companies should avoid making predictions.
In the Phase 3 trials,鈥痯harmaceutical companies鈥痸accinate study participants and then see if they become infected鈥痠n the鈥痗ourse of鈥痶heir daily lives.鈥疻hen rates鈥痮f the virus鈥痝o down,鈥痜ewer participants will become infected, which slows down the trial.
Even after鈥痶he鈥痗linical trials are completed, there can be problems with manufacturing.鈥疶hat's been true for many vaccines and鈥痗ould be true of the Covid-19 vaccines as well.
"People don't think about manufacturing,鈥痓ut manufacturing has killed a lot of products," said鈥疦orman Baylor, former director of the FDA's Office of Vaccines Research鈥痑nd鈥疪eview.
Drugs鈥痶ypically use chemicals,鈥痓ut vaccines deal with growing living material, which doesn't always go as planned.
"It's wilder and crazier when you're involving living systems," Baylor said. "Manufacturing a vaccine is a lot like cooking.鈥疉 recipe may work fine one day but not the next."
That's why vaccine experts say the best laid plans can go askew.
"The best-case scenario never happens," said Michael,鈥痶he鈥痙irector of the Center for Infectious Disease Research at the Walter Reed Army Institute of Research. "Bumps and warts happen in vaccine development."