Immunity to Vaccine-Preventable Infections in Healthcare Professionals Working in Infectious Diseases Hospitals

Relevance. During the ongoing pandemic of a new coronavirus infection (COVID-19), assessment of humoral immunity to vaccine preventable diseases in healthcare workers is crucial to estimate the risk of healthcare-associated infections. Aim. To assess the humoral immunity to vaccine-preventable diseases: whooping cough, influenza A, viral hepatitis A and B, new coronavirus infection (COVID-19), in healthcare professionals working with infectious patients. Materials and methods. We conducted a cross-sectional study enrolling 252 healthcare workers, which included a survey and assessment of immunoglobulins G to Bordetella pertussis, influenza A virus, hepatitis A virus, HBsAg and HBcAg of hepatitis B virus, and SARS- COV-2 by enzyme immunoassay. Results. The proportion of healthcare workers seronegative to pertussis was 46.8%, to influenza – 31.4%, to hepatitis A – 52.4%, to hepatitis B – 27.5%, to the SARS-CoV-2 virus – 29.8%. In 8.0% of cases the level of antibodies to Bordetella pertussis indicated a recent infection. The largest proportion of seronegative to pertussis (55.2%) was among individuals younger than 30 years. More than 80% of healthcare workers were vaccinated against seasonal influenza A during the previous year, 67.6% of them were seropositive. More than half (51.8%) of vaccinated but seronegative to influenza A health workers were older than 50 years. The odds of being seropositive to influenza A decreased with age, while the odds of being seropositive for viral hepatitis A increased with age. Vaccination against viral hepatitis B was received by 86.9% of people, 78.5% of them were seropositive to HBsAg, the remaining 21.5% needed revaccination. The proportion of healthcare workers seropositive for the SARS-CoV-2 virus was 57.5%, equivocal results were obtained in 12.7% of cases. The proportion of seronegative among those who had previously had COVID-19 was 40%, while among those who were vaccinated – 17.4%. Conclusion. The study showed a complex assessment of humoral immunity to the most common vaccine-preventable diseases: pertussis, influenza A, viral hepatitis А, B and novel coronavirus infection (COVID-19) in healthcare workers during the ongoing pandemic and allowed to make the following conclusions: 1. The proportion of healthcare workers susceptible to pertussis was 46.8% that required regular vaccination/revaccination of the seronegative healthcare workers to reduce the risk of infections healthcare-associated infections. 2. The pro