You have asked us through our Instagram consulting account how many people infected with covid-19 have the full vaccination pattern and are, therefore, immunised. You also wanted to know the efficacy of each vaccine brand in front of the Delta variant of SARS-CoV-2
You have asked us through our Instagram consulting account how many people infected with covid-19 have the full vaccination pattern and are, therefore, immunised. You also wanted to know the efficacy of each vaccine brand in front of the Delta variant of SARS-CoV-2. We have investigated it and this is what we have found.
People with the full vaccination pattern infected of covid-19 are 10% of the infected people in Catalonia in the fifth wave. This is stated in the press release published by the Department of Health of the Generalitat de Catalunya on 21 July, which states that "in this fifth wave 141,083 cases [positive for covid-19] have been accumulated, of which 14,291 are post-vaccination". Carmen Cabeza, Secretary of Public Health, specified in a press conference (minute 13:30) that this datum refers to people who have completed the vaccination pattern 14 days or more ago and are therefore immunised against covid-19.
The Department of Health has also reported that almost three out of every four people admitted to intensive care during July (73.5% of 487 admissions) have not received any injection, while 13.5% have the full vaccination pattern.
In the same sense, Carolina Darias, Minister of Health of the Spanish Government, declared on Sunday 20 July in a press conference (minute 16:25) that 83% of the infections in the whole of Spain in the last 5 weeks correspond to people who have not been vaccinated, while only 5.5% of those who are positive for covid-19 have been fully vaccinated.
Efficacy towards the Delta variant
The studies of the efficacy of the vaccines towards the Delta variant are still very preliminary and scarce. The majority of the data come from the United Kingdom, where this variant already represents 99% of covid-19 cases of the country. Just on July 21, The New England Journal of Medicine published an article comparing the efficacy of the Pfizer/BioNTech and Oxford/AstraZeneca formulas with the symptomatic contagion for the Alfa and Delta variants.
The analysis has concluded that “the differences in the efficacy of the vaccines after two doses are small”, between both variants in both the Pfizer and AstraZeneca formulas. That is, the researchers consider that the vaccines have a similar efficacy against both the Alpha and Delta variants of SARS-CoV-2: with Pfizer's vaccine, this parameter is reduced from 93.7% to 88%, while with AstraZeneca's, it goes from 74.5% to 67%.
The same research group has shared a pre-print (an article that has not yet been published in any journal or peer-reviewed) in which they analyse the efficacy of the two formulas in preventing hospitalisation. The results, still pending review, show that both Pfizer and AstraZeneca provide better protection against hospitalisation in people infected with the Delta variant than those infected with the Alpha variant. However, the differences between the two vaccines are still small.
The other approved vaccines in Europe
Johnson & Johnson and Moderna have also pronounced regarding the efficacy of their respective formulas in front of the Delta variant, indicating that respective pre-prints show that a neutralising response in front of the mutation is awaked. However, there is no numerical data about the incidence of the Delta variant in vaccinated people with these formulas.