RIO DE JANEIRO, BRAZIL – Combining AstraZeneca’s Covid-19 vaccine with a second dose of either Pfizer-BioNTech or Moderna’s immunizer provides “good protection,” the Danish State Serum Institute (SSI) said Monday, August 2.
A growing number of countries are considering switching to different Covid-19 vaccines to administer second doses, a measure particularly necessary in Denmark since health authorities suspended inoculations with AstraZeneca’s vaccine in April over concerns of rare adverse reactions.
Over 144,000 Danes, mostly frontline health care professionals and the elderly, were given a first dose of AstraZeneca’s immunizer, but were subsequently vaccinated with either Pfizer-BioNTech or Moderna vaccines.
“The study shows that 14 days after a combined vaccination program, the risk of SARS-CoV-2 infection is reduced by 88% compared to non-vaccinated individuals,” the SSI said.
This is a “high efficacy,” the SSI added, comparable to the 90% efficacy rate of two doses of the Pfizer-BioNTech vaccine, another Danish study confirmed.
The study published last week covered a period of over 5 months between February and June this year, during which the Alpha variant of the coronavirus was prevalent. It was unable to determine whether the same protection applies to the Delta variant, which is now the most widespread in Denmark.