How effective are vaccines against Delta variant? Reports vary as immunized patient dies in Calgary hospital
CALGARY -- As confirmed cases of the Delta variant of COVID-19 continue to rise in Alberta, there are conflicting statements regarding how effective the first dose of vaccine is at protecting against severe outcomes of infection.
Alberta Health Services confirms a patient in their 80s, who had received two doses of MRNA vaccine before contracting the Delta variant, died in an outbreak at the Foothills Medical Centre in Calgary. A second unvaccinated patient, who was also over the age of 80, also died in the outbreak.
The outbreak at the hospital in northwest Calgary now spans two units with confirmed cases in 21 patients and nine staff members.
In response to those outbreaks, AHS says vaccines were given to those in hospital at risk of exposure to the Delta variant — also known as B.1.617.2, that was first identified in India.
Earlier this month, AHS officials told CTV news a first dose of an MRNA vaccine such as Pfizer or Moderna offers 33 per cent protection against the Delta variant with a single dose and coverage increased to 88 per cent with a second dose.
Yet, on Monday, Premier Jason Kenney tweeted a report from the United Kingdom — where cases of the Delta variant are rising —indicating one dose of Pfizer vaccine is 94 per cent effective against hospitalizations involving the Delta variant and increases to 96 per cent after a second dose.
Alberta confirmed its first case of this variant of concern on April 8.
According to the latest data, it has spread to 356 confirmed cases, with more than 300 in the Calgary health zone.
University of Calgary biologist and member of the 'COVID-19 to Zero' advocacy group Gosia Gasperowicz says the exponential growth of this variant could potentially result in as many as 2,000 daily new cases in Alberta by early August.