Estonian virologist: Only small share of vaccinated people catch COVID-19

TALLINN - Irja Lutsar, head of the anti-COVID-19 research council advising the Estonian government, told Postimees that 80 percent of the people who catch the coronavirus have not been vaccinated and the share of unvaccinated individuals among the people requiring hospital treatment is over 90 percent, which means that the coronavirus vaccine is working as intended.

Unvaccinated young people continue to be the ones to catch the virus the most and the age groups represented with the largest numbers in infection figures vary from one day to the next -- on some days, the number of newly infected people is largest in the segment of people aged 20-40, on others it is in the 15-40 age group.

"Elderly unvaccinated people have mainly been the ones to require hospital treatment so far," Lutsar said.

The Estonian Health Board told Postimees than none of the coronavirus vaccines currently in use is 100 percent effective.

"The vaccines by both Pfizer/BioNTech and Moderna proved 93 to 95 percent effective in clinical trials. This means that one vaccinated person in 20 may nonetheless not develop sufficient protection, catch the virus and spread it to others," spokesperson for the Health Board Kirsi Pruudel said. 

"In comparison, the efficiency of flu vaccines is up to 60 percent. With coronavirus vaccines, however, we appear to have become used to an idea of perfect protection as the efficiency of mRNA vaccines exceeds 90 percent. People forget that a strong impact is also produced in the society by much lower efficiency," she said. 

COVID-19 vaccines protect against a severe course of the illness but do not fully prevent contracting the virus or spreading it to other people.

"This is also proven by our reality -- over 700 people in Estonia have contracted COVID-19 to date after achieving maximum protection, according to the Health Board's data," Pruudel said.

"I also want to point out that we do not have an overview of how many vaccinated people have come into contact with a virus carrier," she noted.

The spread of the delta strain of the coronavirus must be treated separately.

"The vaccines in use may not be as efficient against the delta strain. In general, the course of the illness is less severe for vaccinated people, however," Pruudel added.

As at last Monday, 777 people had contracted the coronavirus after having achieved maximum protection against the virus. Of the daily new infection cases, on average 80 percent have not been vaccinated, 15 percent have achieved maximum protection and 5 percent have yet to complete their vaccination course.

The Estonian national expert committee on immunoprophylaxis said last week that there is at present not enough research-based data regarding the need for COVID-19 revaccination or the efficiency and safety thereof. Lutsar said that revaccinations will need to be targeted with great detail and precision.

"We cannot make these decisions without any research. Studies are currently being conducted in the United Kingdom, Norway and Turkey," Lutsar said. "We do not know yet what the side effects of the third dose are and if it even helps increase the level of antibodies. Additionally, we also need to know when the third dose should be administered after full vaccination," Lutsar said, adding that these are all questions that have yet to be answered globally.