| A day after announcing its trials showed 100% efficacy for adolescents aged 12 to 15, Pfizer announced Thursday that its COVID-19 vaccine provides protection for at least six months after the second dose.
The vaccine remains more than 91% effective against disease with any symptoms for six months, according to a joint statement from Pfizer/BioNTech. And it appeared to be fully effective against a worrying variant of the virus — the dominant strain circulating in South Africa and which researchers feared had evolved to evade the protection of vaccines.
Pfizer has been studying the vaccine in more than 46,000 volunteers and has noted 927 cases of confirmed COVID-19.
“The vaccine was 100% effective against severe disease as defined by the U.S. Centers for Disease Control and Prevention (CDC), and 95.3% effective against severe COVID-19 as defined by the U.S. Food and Drug Administration (FDA),” Pfizer and BioNTech said in a joint statement.
These definitions matter. The FDA’s definition of severe disease included a raised respiratory rate indicating respiratory distress; raised heart rate, an oxygen saturation level of 93% or lower; respiratory failure severe enough to need additional oxygen or ventilation; a blood pressure drop indicating shock; significant kidney, liver or neurological dysfunction, admission to an intensive care unit or death.
CDC’s definition includes a blood oxygen level of 94% or lower and an X-ray finding of lung infiltrates — an indication of pneumonia — of greater than 50%.
The most common adverse events reported were pain at the injection site, fatigue and headache.
Pfizer has followed up with more than 12,000 vaccinated participants for six months after their second dose. | 
No comments:
Post a Comment
Keep a civil tongue.