Image source: Pixabay
Combining AstraZeneca plc’s (NYSE: AZN ) COVID-19 vaccine with a second dose of the mRNA vaccines made by either Pfizer-BioNTech (NYSE: PFE ) (Nasdaq: BNTX ) or Moderna (Nasdaq: MRNA ) has high efficacy against the virus, a new Danish study found.
The report, published last week by Denmark's State Serum Institute (SSI), found that 14 days after a combined vaccination program, the risk of infection drops by 88% compared to unvaccinated individuals.
The SSI noted that the results are comparable to the 90% efficacy rate of Pfizer’s two-shot vaccine.
The study was conducted between February and June of this year, a period in which the Alpha variant of the virus was the predominant strain.
It did not conclude if the same level of protection applied to the Delta variant, currently the most widespread in Denmark. It also provided no efficacy data on coronavirus-related deaths or hospitalizations, since none occurred following the combined vaccination program, according to Reuters.
Public health experts' opinions vary, and the overall data remains preliminary on whether or not it is safe to combine mRNA-based vaccines and adenoviral vector vaccines such as AstraZeneca's.
Nonetheless, many countries, including Germany and Canada, are moving ahead with the approach, often in response to supply challenges.
In April, Denmark became the first country to remove the AstraZeneca vaccine from its national vaccination program due to concerns over rare side effects. Shortly after, it discontinued use of the Johnson & Johnson one-shot vaccine.
Since then, the country’s rollout continued with the double-dose vaccines made by Pfizer and Moderna.
As a result, about 150,00 Danes — primarily healthcare workers and senior citizens — received their first jab with AstraZeneca but were subsequently vaccinated with shots from Pfizer or Moderna, according to The Copenhagen Post.
The study comes as Denmark’s health ministry is weighing if a third shot should be offered to people who have received two different doses.
Outside of the European Union, some countries do not accept cross vaccination as a valid form of immunity, which could make traveling complicated.
Source: Equities News