Estonia allows combined use of vaccines

Illustrative photo of Covid-19 vaccine. Photo: Sander Ilvest

Even though Estonia’s official position was not to allow cross-usage of vaccines as recently as last week, the national immunoprophylactic expert committee has decided to allow combining vaccines in cases where the first dose has caused severe side-effects.

Combining two different vaccines is now allowed with a corresponding decision from the person’s physician, Deputy Director of the Health Board Mari-Anne Härma said at the COVID-19 situation press conference on Wednesday.

Head of the vaccination effort in Estonia Marek Seer said that in most cases, immunization should be completed using the same vaccine. Seer urges people not to miss their second vaccine shot as all vaccines used in Estonia protect against the so-called Indian or Delta strain of the virus if both doses are administered. “The AstraZeneca vaccine usually has milder side-effects after the second dose, while it is the opposite for the Pfizer vaccine, which is why changing vaccines half-way needs to be carefully considered,” Saar said in a comment sent to Postimees.

“There is enough proof to suggest that cross-usage of two vaccines is probably just as effective. While I also believe it is a good idea, there is not as much scientific data on combined use of vaccines compared to using the same vaccine,” said Marje Oona, assistant professor of family medicine at the University of Tartu. “If someone has had a bad reaction to the AstraZeneca vaccine, perhaps it is better to switch to an mRNA alternative.”

Oona emphasized, however, that it would be unfortunate were people who have already booked their second vaccine shot would start to postpone or reschedule in hopes of getting a different vaccine.

Delta strain on the rise

The Health Board estimates that the relative importance of the Delta or so-called Indian strain of the virus has doubled in Estonia over the last ten days. Member of the government’s scientific advisory committee Irja Lutsar said that University of Tartu researchers had sequenced a total of 42 samples of the Delta strain by Tuesday. Health Board puts the total number of Delta strain diagnoses at 55.

Around 20-30 percent of new cases are confirmed as the so-called Indian strain today, while the overall infection rate continues to fall, Mari-Anne Härma said. Member of the scientific advisory committee Krista Fischer said that the Delta strain could start to dominate by late June. “It spreads much more effectively than the British mutation,” she said.

The first outbreak of the Indian strain got started at the graduation ceremony of the Kehtna Art School where students and a family member got ill. The person who started the outbreak came from Russia. “People should definitely get tested upon returning from abroad,” Härma said.