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Covid-19 vaccine predictions have already failed

2020-11-02T16:20:50.790Z


Pharmaceutical companies have made several predictions about the timing of the Covid-19 vaccine that have turned out not to be true.


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(CNN) -

Baseball star Yogi Berra once said, "It's hard to make predictions, especially about the future."

Yogi Berra did not know anything about covid-19 - he died five years ago - but his appointment applies to the development of a vaccine against the new coronavirus.

Over the past six months, drug companies have made various predictions about the timing of the Covid-19 vaccine that have turned out to be untrue.

A recent example is from Pfizer.

The company had said for weeks that it would know by the end of October whether or not its vaccine works, but on Tuesday, in a call from investors, the company's chief executive basically ruled out that possibility.

While Pfizer and other companies have at times qualified their statements, at other times they have been more definitive about their projections.

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Scientists say that should guide us as we get closer to having a vaccine: Don't believe everything you hear, because testing and manufacturing vaccines is notoriously unpredictable.

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"Unexpected things happen all the time in vaccine development," said Dr. Nelson Michael, an Army vaccine specialist who worked on more than 20 vaccine clinical trials.

"There are tons of unexpected changes, and it is important to understand that," he added.

There are health officials who have also made statements going forward.

However, in general they have been more vague than those of the pharmaceutical companies.

Last week, the director of the National Institutes of Health, Dr. Francis Collins, told the National Press Club that he remains "cautiously optimistic" that the United States could have a licensed Covid-19 vaccine by the end of the year.

But he warned that "it could take longer."

Dr. Paul Offit, a member of the US Food and Drug Administration's (FDA) vaccine advisory committee, said drug companies would do well to stop forecasting their timing.

"Companies should stop making predictions, because nature is so sobering," Offit said.

When they claimed to have a 'near perfect' vaccine

In September, Ugur Sahin, CEO of BioNTech, which is working with Pfizer on its COVID-19 vaccine, told CNN that the company's vaccine is "almost perfect."

Scientists interviewed for this report shuddered at the thought of describing a vaccine as "near perfect" when it has not yet been fully studied in large-scale trials.

Pfizer's vaccine, as well as three others, are still in phase 3 clinical trials in the United States.

Nobody knows if they work, much less if they work almost perfectly.

Pfizer and another pharmaceutical company, Moderna, use a new type of technology in their covid-19 vaccines that no vaccine on the market has ever used.

Offit said that alone is reason for caution.

“This virus has been around for less than a year and causes a variety of clinical findings that we would never have predicted.

And now we are going to counteract it with a vaccine that has no commercial experience?

How about a little humility here? ”Said Offit, a member of the FDA's Advisory Committee on Vaccines and Related Biologics.

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According to a BioNTech statement sent to CNN, Sahin's comment “was based on preliminary antibody and T-cell responses and a favorable safety profile seen in the study thus far.

He also pointed out that it is necessary to wait for data on efficacy that are not yet available.

Pfizer's chief executive has made predictions about when it will become clear whether a vaccine works or not.

On September 8, Albert Bourla told the Today show, "we will have an answer by the end of October" on whether the vaccine works.

“Our model, our base case, predicts that we will have a response in, at the end of October.

Of course, this is just a prediction, "he added.

On October 16, Bourla made a similar comment in an open letter on his company's website.

"We may know if our vaccine is effective or not by the end of October," he said.

But in Tuesday's investor call, just five days before the month was out, Bourla said the company had not yet seen the data on its vaccines.

Pfizer's first chance to see that data will be when 32 people in his test become ill with COVID-19, and Bourla told investors this has yet to happen.

Reaching those 32 coronavirus cases won't give the company the data it needs.

An independent panel of experts will need to look at 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.

CNN contacted Pfizer for a response.

“I don't think we or our CEO said that the world should definitely expect an announcement by the end of the month.

Rather, there was a chance we would know about effectiveness by the end of the month.

Nothing has changed, ”according to a company spokesperson.

Oxford University predictions on September results

Pfizer is not the only company that has made predictions that are unlikely to come true or no longer come true.

In April Sarah Gilbert, a researcher at Oxford, told

The Times

in the UK that she was "80% sure" that the vaccine her team was developing would work.

This although at that time Oxford had not even started its phase 3 clinical trials.

In May, CNN asked Oxford researcher Dr. Adrian Hill when the university test would end.

“My guess is that July would be (a deadline) good.

August is more likely.

It could be September, ”he said.

"We are aiming for September, but we hope to finish earlier."

September came and went.

Even now, the Oxford Phase 3 trial is still underway.

"We have seen with this pandemic that the spread and transmission rates have fluctuated, making it difficult to predict, and important measures to control cases, such as the closure defined by the UK government, have slowed the transmission rate" wrote an Oxford spokesperson in an email to CNN.

"We have consistently argued that if transmission remains high, we could get enough data in a couple of months to see if the vaccine works, but if transmission levels go down, this process could take longer," he added.

Viruses, and vaccines, are unpredictable

The spread of a virus is unpredictable.

And vaccine experts say that's exactly why drug companies should avoid making predictions.

In phase 3 trials, drug companies vaccinate study participants and then see if they become infected in the course of their daily lives.

When rates of the virus drop, fewer participants are infected, which slows down the test.

Even after clinical trials are completed there can be problems with manufacturing.

That has happened in many vaccines and could also happen with the covid-19 vaccine.

"People don't think about manufacturing, but manufacturing has killed a lot of products," said Norman Baylor, former director of the FDA's Office of Vaccine Research and Review.

Medications often use chemicals, but vaccines deal with live, developing material, which doesn't always go as planned.

"It's wilder and crazier when you involve living systems," Baylor said.

“Making a vaccine is a lot like cooking.

A recipe may work well one day but not the next, ”he added.

That's why vaccine experts say the best-laid plans can go wrong.

"The best case scenario never happens," said Michael, director of the Infectious Diseases Research Center at the Walter Reed Army Research Institute.

"Bumps and warts occur in vaccine development," he added.

Bumps and warts happen in vaccine development. 

Or, to quote Berra once more: »it is not over until it is over«.

CNN Health's John Bonifield and Sierra Jenkins contributed to this story.

covid-19 coronavirus vaccine

Source: cnnespanol

All news articles on 2020-11-02

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