To date, more than 141 million Americans and more than 33 million Britons have received the first covid-19 vaccine, which is administered in two doses.

According to a study of 375 people in the UK, the Pfizer and Astra-Zeneka vaccines provided 000% protection against symptomatic covid-72 infection. Studies show that protection from one dose of the vaccine lasts at least 19 weeks, but that getting a second dose is important because then Pfizer protection increases to 10%.

Another field study from Scotland, published in The Lancet, found that a single dose of Pfizer vaccine was 91% effective against hospitalization, 28 to 34 days after vaccination. A single dose of Astra-Zeneka vaccine protects against 88% of severe symptoms that could lead to hospitalization.

A study conducted in England showed that a single dose of Pfizer or Astra-Zeneka vaccine reduces the spread of symptomatic infection in family members by 50%.

Pfizer protects at least 80% after the first dose

According to US Food and Drug Administration (UHL) documents, the first dose of Pfizer was 52,4% effective in protecting against symptomatic infection with covid-19. However, this estimate also includes a period of 11 days before the start of the first dose, so the actual protection should be higher and be between 29,5% and 84,5%.

According to clinical trial data, the first dose of Pfizer was 100% effective in protecting against hospitalization and death.

Medical statistician Stephen Evans of the University of London says that, based on an overall assessment of UHL data, there is "fairly clear evidence" that a single dose of Pfizer vaccine protects at least 80%, if not 90%, of symptomatic coronavirus infection. .

"Modern" - at least 80%

The "Modern" vaccine was 69,5% effective in preventing symptomatic coronavirus between the first and second doses during human trials, with a true value between 43,5% and 84,5%.
This estimate of 69,5% also includes the period of 13 days before the vaccine starts working, so the real percentage should be higher.

Evans says that based on available data, the Moderna vaccine provides at least 80% protection after the first dose, or more likely 90%, within 28 days of starting the action.

Astra-Zeneka protects at least 70% after the first dose

According to a study published Feb. 19 in The Lancet, a single dose of Astra-Zeneka was 76% effective, with 90 days of protection against symptomatic covid-19. Experts in the study stated that a single dose provides 100% protection from hospitalization.

Johnson & Johnson - 66%

The Johnson & Johnson Vaccine begins to protect 14 days after vaccination and provides 66,1% protection over the next 28 days. The effectiveness of this vaccine varies from country to country. In the United States, the vaccine was 72% effective, in South Africa 64%, and in Brazil 68%, but it should be noted that in Brazil and South Africa there are strains that may be somewhat resistant to antibodies formed after vaccination with this vaccine.

Source: Index.hr