Pfizer says its coronavirus vaccine helps prevent COVID-19, marking a milestone in the fight against the pandemic

[steven36]

• Pfizer's experimental coronavirus vaccine succeeded in the final stage of clinical trials, the drugmaker said Monday, a milestone in society's fight against the pandemic.
• Developing an effective vaccine against a brand-new virus in less than a year is an unprecedented feat in medicine.
• The study found people who got Pfizer's shot were less likely to develop COVID-19, the disease caused by the novel coronavirus. The drugmaker said the shot was found to be more than 90% effective in preventing COVID-19.
• Pfizer described the results in a press release. The trial is still ongoing, and the interim results have not been published in a peer-reviewed medical journal.
• The vaccine will not be distributed immediately. It still needs to be evaluated by the US Food and Drug Administration.

 

 

A leading coronavirus vaccine candidate worked to prevent people from developing COVID-19, a milestone in society's war against the pandemic.

 

The pharmaceutical company Pfizer on Monday said its vaccine succeeded in the final stage of clinical trials, which compared tens of thousands of volunteers who received two doses of the experimental vaccine against a group receiving a saltwater placebo.

 

The drugmaker said the shot was found to be more than 90% effective in preventing COVID-19, based on 94 cases of the disease observed in the study.

 

Next, the New York drugmaking giant plans to apply for emergency authorization that would allow it to distribute the shot more widely. The company still needs more data on how safe the vaccine is before asking for the emergency OK, and it has said it won't have the necessary information until later this month.

 

Pfizer and its German partner BioNTech are the first to report positive results from a pivotal trial of a COVID-19 vaccine. Developing and testing an effective vaccine in less than a year is an unprecedented accomplishment in medicine. Shares of Pfizer and BioNTech soared in premarket trading Monday morning. Markets broadly rose on Monday, celebrating the success of the vaccine as a critical piece to confronting the pandemic.

 

While the study is still ongoing and will collect follow-up safety and efficacy data, the key conclusion from an interim analysis is that the vaccine works.

 

"Today is a great day for science and humanity," Pfizer CEO Albert Bourla said in a statement. "The first set of results from our Phase 3 COVID-19 vaccine trial provides the initial evidence of our vaccine's ability to prevent COVID-19."

 

Questions remain, however, such as how long the vaccine will work for and whether any rare, yet serious, side effects have yet to be detected.

 

The impact of the success won't be immediate on society. Key challenges now shift from the scientific realm to regulatory, logistical, and political. Regulators have to review the data and decide whether there's enough evidence to approve the shots. Supplies will also be extremely limited for the first few months as production is ramped up.

 

Pfizer's vaccine will also pose unusual logistical challenges. It needs to be shipped and stored at minus 94 degrees Fahrenheit. The Centers for Control Disease and Prevention has estimated the US will have a supply of about 20 million to 30 million doses of Pfizer's vaccine in 2020, translating to enough doses to vaccinate less than 10% of the US population.

 

If the vaccine gets an emergency approval, it won't be available to everyone at once. The first people eligible to get the shots may be those at high-risk of falling ill, such as frontline healthcare workers and older people.

 

Even when people start getting vaccinated, experts have stressed it will be essential to keep wearing masks and socially distancing.

 

While the study succeeded in its primary goal of reducing symptomatic COVID-19 cases, that may not necessarily mean the shot prevents asymptomatic infection or serious illness.

 

That means vaccinated people could still be unknowing carriers of the virus and may still face a risk of developing severe COVID-19 that requires hospitalization and may even result in death. Longer-term data from the study could help answer these questions.

 

Initial results are limited, but Pfizer touts strong efficacy

 

These results came from an interim analysis of the study, which is still ongoing. The trial will carry on through its final analysis of 164 COVID-19 cases, which should help produce more rigorous results over time.

 

The trial recruited 43,538 volunteers, randomly given the vaccine or placebo injections. Researchers designed the study to count COVID-19 cases among the trial participants. Once a certain number of volunteers got sick, an independent board of experts reviewed the data to see whether those getting the experimental vaccine were far less likely to fall ill than those getting the saltwater placebo.

 

The primary goal was to see whether the vaccine reduced COVID-19 cases after getting both doses. The trial protocol specified a COVID-19 case as someone who both tests positive and displays symptoms. Researchers counted cases starting a week after the volunteer received the second dose. Pfizer on Monday said protection from the virus was achieved after 28 days after the initial dose.

 

There is no long-term follow-up data available for people given Pfizer's vaccine. That means critical questions about the durability of the shot's protection as well as the risk of any long-term side effects remain unknown.

 

The study will carry on to address those questions. Experts noted that vaccine trials are rarely able to identify ultrarare side effects, which can be one-in-a-million events. US health agencies have surveillance systems to track vaccine efficacy and safety after a shot is released to the public.

 

Pfizer is preparing for a speedy approval

 

Through the coronavirus vaccine initiative Operation Warp Speed, the US government has spent months preparing for success in the clinic.

 

The US government reached a deal in July with Pfizer to buy 100 million doses for $1.95 billion. That contract also included an option to buy up to 500 million more doses. Pfizer has reached deals with dozens of governments around the world, beyond the US, allocating fragments of initial supply to many countries.

 

In total, Pfizer expects to make 50 million doses in 2020 and up to 1.3 billion doses in 2021.

 

The US Food and Drug Administration will decide whether to authorize the experimental vaccine. The agency is expected to quickly convene an independent panel of experts to review the data after Pfizer submits its application. While Pfizer has said it should have enough safety data from the study by the third week of November to submit the vaccine for review, it's unclear how quickly the regulatory process will move from there.

 

The FDA's expert panel typically has a lengthy public meeting to ask questions about the rigor of the data and the risks and benefits of approving an experimental medicine. FDA scientists then take that group's recommendations into consideration and ultimately make an approval decision.

 

Typically, the agency takes six to 10 months to review applications for new drugs and vaccines. While it's widely expected that timeline will be dramatically accelerated given the urgency of the pandemic, a precise timetable is unclear.

 

While Pfizer's vaccine is the first to report successful late-stage trial results, several other drug developers are aiming to quickly follow with results for their own vaccines.

 

The other frontrunners are the Massachusetts biotech Moderna; the British pharma giant AstraZeneca and the University of Oxford; the world's largest healthcare company, Johnson & Johnson; and the small Maryland biotech Novavax.

 

Vaccines developed by all those drugmakers have started the final stage of clinical testing. Moderna expects to report results in November, while AstraZeneca is aiming to have data before year's end. J&J and Novavax will most likely have results slightly later, aiming for late 2020 or early 2021.

 

Pfizer's success is expected to boost confidence in other vaccines, as all these shots target the same portion of the coronavirus: its spike protein. It is also validation for promising technology in vaccine research that has remained unproven until now. Pfizer's candidate is a messenger RNA vaccine, which requires just the genetic code of the virus to engineer an experimental vaccine.

 

Pfizer's readout is the first success in an efficacy-focused study to show the technology works in humans. Moderna also specializes in mRNA therapeutics and vaccines and was the world's first drugmaker to start testing a COVID-19 vaccine in humans in March.

 

Source

[Karlston]

Here’s everything you need to know about Pfizer’s positive vaccine news

Pfizer announces vaccine is more than 90% effective, but data not yet released.

Enlarge / A woman wears a facemask as she walks by the Pfizer world headquarters in New York on November 9, 2020.

Getty | KENA BETANCUR

119 with 75 posters participating

An experimental mRNA coronavirus vaccine developed by pharmaceutical giant Pfizer and German firm BioNTech appeared to be more than 90-percent effective at preventing symptomatic COVID-19 cases in an interim analysis of their large Phase III clinical trial.

 

The two companies reported the top-line results of the analysis in a press release early Monday but have not yet published or released detailed data from the trial.

 

The companies said that they could file for an Emergency Use Authorization (EUA) from the US Food and Drug Administration in the third week of November. That’s the point at which the companies will have a median of two months of safety monitoring data on trial participants, a milestone specified by the FDA—at the objection of the Trump administration.

 

“Today is a great day for science and humanity,” Pfizer CEO Albert Bourla said in the press release.

 

Outside researchers and experts echoed the optimism but added caution, noting the lack of detailed data.

 

“This news made me smile from ear to ear,” Peter Horby, professor of emerging infectious diseases and global health at the University of Oxford, said in a press statement. “It is a relief to see such positive results on this vaccine and bodes well for COVID-19 vaccines in general. Of course, we need to see more detail and await the final results, and there is a long, long way to go before vaccines will start to make a real difference, but this feels to me like a watershed moment.”

How the vaccine works

As Ars has reported previously, Pfizer and BioNtech’s vaccine, BNT162b2, is an mRNA-based vaccine. Like Moderna’s vaccine, BNT162b2 uses a fatty nanoparticle wrapping to deliver a fragment of genetic code—in the form of messenger RNA, or mRNA—from the pandemic coronavirus, SARS-CoV-2, into human cells. Specifically, the bit of code delivered is a snippet of the virus’s blueprint for the infamous spike protein, which is what the virus uses to latch onto human cells and initiate an infection.

 

Once delivered inside human cells, the genetic snippet of the spike protein is read by cellular machinery, which then produces the protein fragment. From there, the fragment is used to train the immune system to detect and destroy the virus. Setting the immune system’s crosshairs to the spike protein is thought to be the most efficient way to defeat the virus, since the spike protein is an extremely conspicuous protein on the outside of the virus—and one critical to initiating an infection. Most vaccines under development focus on the spike protein, and the most potent antibodies known to defeat the virus—neutralizing antibodies—also attack the spike.

Earlier data and scale-up

Pfizer and BioNtech have previously published data on their vaccine, showing that it prompted immune responses against SARS-CoV-2 and was generally safe, with no serious side effects. Common mild side effects included pain at the injection site, fatigue, fever, headache, chills, and muscle pain. They noted that the vaccine appeared to prompt higher levels of antibodies and neutralizing antibodies against SARS-CoV-2 than was seen in people who had recovered from a natural infection with SARS-CoV-2. They also reported that the vaccine spurred strong T-cell responses, which may be critical for longer-term immune protection.

 

mRNA vaccines have been a hot topic in research for several years, but so far, there are no licensed vaccines that use this method. This has given some experts pause about the ability to quickly scale up production. The vaccines also require extreme cold storage (-70 degrees Celsius in the case of BNT162b2), which adds to the daunting logistical challenges of vaccinating the worldwide population.

 

Still, the apparent early success of BNT162b2 bodes well for similar vaccines in development. The Coalition for Epidemic Preparedness Innovations (CEPI) celebrated the news, saying in a press statement:

 

“These are hugely positive and encouraging interim results and are testament to the ingenuity and skill of the scientific community in advancing vaccine candidates against COVID-19… We believe these interim results also increase the probability of success of other COVID-19 candidate vaccines which use a similar approach [pre-fusion spike as their immunogen], including all of the vaccines in the CEPI portfolio.”

 

CEPI is co-leading an effort to set up a global vaccine alliance, the COVAX Facility, along with the World Health Organization and Gavi, the Vaccine Alliance.

The Phase III trial

Pfizer and BioNTech began their Phase III clinical trial of BNT162b2 on July 27, enrolling 43,538 participants to date. The trial is international, with enrolling sites in the United States, Argentina, Brazil, South Africa, Germany, and Turkey. Of those enrolled already, 38,955 received their second dose of BNT162b2 as of November 8, 2020.

 

There are 10 COVID-19 vaccines in Phase III trials so far, but the Pfizer/BioNTech trial is considered the frontrunner, as it was built for speed. For instance, people in the Pfizer/BioNTech trial get their two doses of the vaccine just 21 days apart, whereas other trials space out two doses by 28 days. The Pfizer/BioNTech trial also begins to monitor participants for COVID-19 earlier than other trials, at seven days after the second dose rather than at 14 days.

 

In addition, Pfizer and BioNTech initially planned to do a first preliminary glimpse—aka an interim analysis—after just 32 volunteers in the trial become ill with COVID-19. That’s in contrast to Moderna’s trial, which planned to conduct an interim analysis after 53 illnesses, and AstraZeneca’s, which will conduct an interim analysis after 75.

 

The success of the vaccine is gauged by how many of the interim cases fall into the group that received the vaccine compared with the group that received a placebo. If most of the cases fall into the placebo group, for instance, the vaccine appears to be effective. Pfizer’s 32-case interim analysis was the first of four planned for the trial, which will run until 164 cases occur.

The interim analysis

But the plans recently changed, according to Pfizer CEO Bourla, who explained in the press release:

 

“After discussion with the FDA, the companies recently elected to drop the 32-case interim analysis and conduct the first interim analysis at a minimum of 62 cases. Upon the conclusion of those discussions, the evaluable case count reached 94 and the DMC [an external, independent Data Monitoring Committee] performed its first analysis on all cases,” Bourla said.

 

The split of COVID-19 cases between the vaccinated and placebo groups indicates a vaccine efficacy rate above 90 percent, at seven days after the second dose, Bourla went on. “This means that protection is achieved 28 days after the initiation of the vaccination, which consists of a two-dose schedule. As the study continues, the final vaccine efficacy percentage may vary. The DMC has not reported any serious safety concerns and recommends that the study continue to collect additional safety and efficacy data as planned. The data will be discussed with regulatory authorities worldwide.”

 

While the news is certainly positive, there are some significant notes of caution. Without full data, it’s unclear if the vaccine is able to prevent severe or fatal cases of COVID-19. The trial also defined cases as those with at least one pre-determined symptom of COVID-19 and a positive test. Thus, the trial data so far doesn’t indicate if the vaccine prevents asymptomatic infection, which can allow the virus to continue to spread undetected. Last, with such limited study, it’s impossible to know so far how long any protection from the vaccine will last. It’s also too early to know if there are rare but serious side effects that will develop later in some participants.

 

For now, Pfizer and BioNTech are preparing the data for publication in a scientific, peer-reviewed journal. They also note that they expect to produce up to 50 million vaccine doses globally in 2020 and up to 1.3 billion doses in 2021.

Politics

Like the rest of the efforts to produce a COVID-19 vaccine so far in the US, today’s news quickly became political. In a tweet, Vice President Mike Pence tweeted that the vaccine’s preliminary success so far was “thanks to the public-private partnership forged by President @realDonaldTrump.”

 

However, Pfizer quickly squashed that link, with Pfizer's head of vaccine research and development Kathrin Jansen telling The New York Times, "We were never part of the Warp Speed. We have never taken any money from the US government, or from anyone."

 

Pfizer and BioNTech did, however, reach a $2 billion deal to rush its vaccine to market in the US if it was found to be effective.

 

Pfizer has stayed in the political realm throughout its vaccine development. For weeks this summer, Bourla had dangled the possibility—and desperate hope of lame-duck President Trump—to have vaccine results before the end of October and the presidential election.

 

The positive news, released the Monday after the election was called for President-elect Biden, has raised some eyebrows.

 

In a call with investors last month, Bourla stressed, “This is not going to be a Republican vaccine or a Democratic vaccine. This is going to be a vaccine for the citizens of the world. I hope that it is going to be effective.”

 

 

Here’s everything you need to know about Pfizer’s positive vaccine news