Some 100 people aged 80 to 96 received their vaccine doses three weeks apart, before the United Kingdom adopted a policy of stretching the time between jabs to 12 weeks. It was also 100 percent effective against severe disease as defined by the CDC, as well as 95.3 percent effective against severe disease as defined by the FDA, the companies said. And it appeared to be fully effective against the worrying B.1.351 variant of the virus, which is the dominant strain circulating in South Africa and which researchers feared had evolved to evade the protection of vaccines, the companies said.
People who are fully vaccinated against COVID-19 can safely travel within the United States and overseas as long as they continue to take precautions like wearing a mask in public, according to new guidancereleased Friday by the the Centers for Disease Control and Prevention. A BLA is an application for full approval.
The study from Pfizer-BioNTech says the vaccine remains highly effective after six months and retains efficacy against the B.1351 variant first detected in South Africa.
The CDC updated its guidelines after new studies showed the strong effectiveness of coronavirus vaccines in protecting against infection.
A second study, the largest study on antibody and cellular immune factors to date, suggests people are likely to be protected against the Wuhan, Kent and Brazilian types of coronavirus following two doses of the Pfizer jab.
The firms said that of these cases, 850 occurred among participants who got the placebo, while 77 were in the vaccinated group. The ongoing research found the vaccine was 91.3% efficacious against the disease a half year after a second dose was administered.
"The antibody levels were so high that they'd gone above the thresholds so they had to dilute them".
But he added it will be crucial to see how long antibody levels are maintained after people have had a Covid-19 vaccine.
'I would not be surprised if this is a vaccine that we only get once'.
The firms on Thursday released the results of a clinical trial they conducted after their vaccine secured authorization for emergency use from the US Food and Drug Administration last December.