Protection was greatest among people who received two doses of an mRNA vaccine, Pfizer or Moderna, or a mixed AstraZeneca and mRNA vaccine.
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The mix-and-match approach used to administer COVID-19 vaccines to some people appears to give high levels of immunity against the new coronavirus, according to a BC study.
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The BC Center for Disease Control study examined the levels of protection offered by two doses of an mRNA vaccine, two doses of the AstraZeneca vaccine, or a combination of the two types.
It found that all the combinations reduced the risk of hospitalization for COVID-19 by more than 90 percent.
Protection was greatest among people who received two doses of an mRNA vaccine, Pfizer or Moderna, or a mixed AstraZeneca and mRNA vaccine.
The risk of infection among those who received mRNA injections and those who received a mixed dose was reduced by between 91 and 92 percent, according to the study.
The risk of hospitalization was reduced by 99 percent for those who received a mixed dose, one point more than those who received only mRNA vaccines.
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People who received AstraZeneca alone had their risk of infection reduced by 72% and their risk of hospitalization by 93%.
The study, conducted from May 30 to September 11 among a sample size of 246,656 people over the age of 18, also found that the vaccines are highly effective against the most transmissible Delta variant.
The vaccines stay strong for at least four months after the second dose of mRNA, the study said. At approximately 16 weeks, protection against infection drops above 80%, while protection against hospitalization is around 95%.
Reference-vancouversun.com