According to a countrywide trial in Sweden, people who got a first dose of the Oxford-AstraZeneca COVID-19 vaccination followed by an mRNA vaccine injection had a reduced risk of infection than those who received both doses of the AstraZeneca preventative.
Since the use of AstraZeneca’s vector-based COVID-19 vaccine for persons under the age of 65 was discontinued owing to safety concerns, all people in Sweden who had previously got their first dose of this vaccination were advised to have an mRNA vaccine as a second dose.
“Having received any of the approved vaccines is better compared to no vaccine, and two doses are better than one,” said Peter Nordstrom, a professor at Umea University, Sweden.
“However, our study shows a greater risk reduction for people who received an mRNA vaccine after having received a first dose of a vector-based, as compared to people having received the vector-based vaccine for both doses,” Nordstrom said.
