Pfizer says its vaccine is 100% effective in young people 1:02
(CNN) -
The ongoing phase 3 clinical trial of the Pfizer / BioNTech coronavirus vaccine confirms that its protection lasts for at least six months after the second dose, the companies said Thursday.
And that also protects against variants.
It's the first look at how long protection lasts for a coronavirus vaccine, and while six months is a modest goal, it's longer than 90 days of protection, the best estimate offered to date.
The vaccine remains more than 91% effective against the disease with any symptoms for six months, the companies said.
And it appeared to be completely effective against the worrying B.1.351 variant of the virus, which is the dominant strain circulating in South Africa and which researchers feared might have evolved to evade vaccine protection, the companies said.
«The vaccine was 100% effective against serious diseases as defined by the US Centers for Disease Control and Prevention (CDC) and 95.3% against severe covid-19 as defined by the Administration of US Food and Drug Administration (FDA), ”BioNTech said in a joint statement.
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Tests show the duration of the vaccine's protection
On Wednesday, the companies said a small test of volunteers between the ages of 12 and 15 showed 100% efficacy in that age group.
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"These data confirm the favorable efficacy and safety profile of our vaccine and position us to submit a Biologics License Application to the United States FDA," said Albert Bourla, president and CEO of Pfizer, in a statement.
A BLA is a request for full approval.
Currently, the vaccine has an emergency use authorization, USA, which does not reach full approval.
"The high efficacy of the vaccine seen up to six months after a second dose and against the variant prevalent in South Africa provides greater confidence in the overall efficacy of our vaccine."
The company has been studying the vaccine in more than 46,000 volunteers and has detected 927 confirmed COVID-19 cases.
"Of the 927 confirmed symptomatic COVID-19 cases in the trial, 850 cases were in the placebo group and 77 cases were in the BNT162b2 group, corresponding to a vaccine efficacy of 91.3%," he said.
Thirty-two cases of severe disease, as defined by the CDC, were seen in the placebo group versus none in the BNT162b2 vaccinated group, indicating that the vaccine was 100% effective in this analysis against severe disease as defined by the CDC, one case was observed, as defined by the FDA, in the placebo group versus one case in the group vaccinated with BNT162b2, indicating an efficacy of 95.3% as defined by the FDA «.
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These definitions matter.
The FDA definition of severe disease included an elevated respiratory rate indicating respiratory distress;
elevated heart rate, an oxygen saturation level of 93% or less;
respiratory failure severe enough to require additional oxygen or ventilation;
a drop in blood pressure indicating shock;
Significant renal, hepatic, or neurological dysfunction, admission to an intensive care unit, or death.
The CDC definition includes a blood oxygen level of 94% or less and a radiographic finding of pulmonary infiltrates, an indication of pneumonia, of more than 50%.
The most common adverse events were injection site pain, fatigue, and headache.
"In South Africa, where the B.1.351 lineage is prevalent and 800 participants were enrolled, nine cases of covid-19 were observed, all in the placebo group, indicating 100% vaccine efficacy," the company said.
"The safety of the vaccine has now been evaluated in more than 44,000 participants 16 years of age and older, and more than 12,000 vaccinated participants have at least six months of follow-up after their second dose."
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