A third dose of the Covid-19 vaccine from Pfizer / BioNTech it is 86% effective in people over 60 years of age. So said an Israeli healthcare provider on Wednesday, citing the initial results of a study with thousands of participants.
ABOUT THE STUDY:
The Israeli Maccabi HMO, which covers about a quarter of the country’s 9.3 million inhabitants. He compared the results of 149,144 people over the age of 60 who received their third dose at least a week ago with 675,630 people who received just two doses. Between January and February.
About 37 people tested positive for coronavirus after the third dose. This compared to 1,064 positive cases among those who received just two doses, Maccabi said in a statement. The groups compared had similar demographic profiles, he added.
Pfizer declines over time …
Maccabi did not provide any information on the severity of the 37 positive cases, or whether they had any underlying disease.
Pfizer said that the efficacy of a vaccine diminishes over time, and a third dose showed significantly higher neutralizing antibodies against the initial SARS coronavirus-2 virus. As well as against the highly infectious Delta beta variant.
The difference between efficacy and effectiveness
Efficacy is the measure used in clinical trials.
Efficacy measures how well a vaccine can prevent symptomatic infection (and sometimes transmission) in clinical trials. This is done under ideal, controlled conditions, comparing people receiving the vaccine with those receiving a saline placebo.
Efficacy is the measure used in the real world.
Efficacy is how well the vaccine performs in the real world outside of clinical trials in a mixed population. A highly effective vaccine is expected to be very effective in the real world, but these measures are unlikely to be the same.
PFIZER EFFICIENCY AGAINST DELTA
In Mexico, the delta variant (B.1.617.2) is now the most common COVID-19 variant. It is almost twice as contagious as the previous variants and could cause more serious illness.
While research suggests that COVID-19 vaccines are slightly less effective against the variants. Vaccines still appear to provide protection against severe COVID-19.
Early UK research suggests that after full vaccination. The Pfizer-BioNTech COVID-19 vaccine is 88% effective in preventing the symptomatic COVID-19 virus caused by the delta variant.
The vaccine is 96% effective in preventing serious diseases with the COVID-19 virus caused by the delta variant. The research also showed that the vaccine is 93% effective in preventing the symptomatic COVID-19 virus caused by the alpha variant.
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