After half a year of coronavirus vaccination, according to preliminary results, up to 60 percent of seniors have significantly lower or no antibodies, according to the organization Podané ruce, which performed the analysis on more than 620 seniors. According to the organization, revaccination with the third dose will soon be necessary for vulnerable groups and it will be necessary to increase the capacity of preventive testing of workers and clients of social services. From June 30 to July 2, the company tested blood samples of 627 seniors for antibodies. Of the seniors who took part in the measurement, 396 were under 75, and 231 were older. They were most often vaccinated with Pfizer, but all types of vaccines are included in the survey, both two-dose and single-dose. The results of the analysis show that the level of antibodies decreases with time from vaccination and with age. Seniors who had covid-19 have higher antibody levels than those who have not had the disease.