The high risk of re-infection with coronavirus among people over 65 can be explained by natural age-related changes or immune aging. All this affects the innate and adaptive defenses of the body, Russia's specialist Elena Belova told the Izvestia newspaper.

In turn, Stanislav Otstavnov, head of the laboratory for the analysis of population health indicators and digitalization of health care, noted that there is still no definite answer to need to vaccinate older people.

"For example, recently it was revealed that the AstraZeneca vaccine provokes blood clots, which at age 65 plus is hardly great news," he said.

According to scientists who published a study in the authoritative edition of The Lancet, the risk of re-infection with coronavirus varies among different age groups of the population. According to experts from the Statens Serum Institut in Copenhagen, every second (52.9%) COVID-19 over 65 years old is at risk of getting sick again.

Moreover, among people under this age, the risk is almost two times lower - 21.1%. Experts came to such conclusions after analyzing 10 million PCR tests conducted in the country since the beginning of the pandemic.