Bacille Calmette–Guérin vaccination of healthcare personnel: changing epidemiology calls for new recommendations in Norway

Abstract

]. Until 2018, bacille Calmette-Guérin (BCG) vaccination was strongly recommended for all unvaccinated personnel and students in the healthcare sector in Norway. From June 2018, only a select group of students and healthcare personnel have been targeted for BCG vaccination, i.e. previously unvaccinated healthcare workers and students under 35 years of age who are caring for adult patients with pulmonary tuberculosis (TB) in hospitals or involved with mycobacterial culture in laboratories. What was the rationale behind this policy change? A short history of BCG in Norway In 2009, Norway was one of the last Western European nations to abandon universal BCG vaccination [1]. Until then, all tuberculin-negative schoolchildren were vaccinated at the age of 12-14 years. In addition, both before and after 2009, vaccination was recommended for newborns with parents from high-incidence countries, for all students and employees <35 years of age in the healthcare sector, and for individuals <35 years of age planning a long-term stay in a country with high incidence of TB (table 1) [2]. Norway's extensive BCG vaccination policies may have been influenced by pioneer studies in the 1920s and 1930s conducted by the physicians Johannes Heimbeck and Olaf Scheel at Ullevål Hospital in Oslo [3]. At a time when Norway had very high TB prevalence, they found that one-half of nursing school students were tuberculin-negative when they started their studies, and all were positive after 3 years, indicating high rates of new infection [4]. Out of 284 tuberculin-negative students who were not vaccinated, 97 fell ill with TB during their studies and 10 died [3]. By administering BCG to volunteer tuberculin-negative nursing and medical students, Heimbeck and Scheel observed a protective effect against TB of ∼80% [2]. Need to revaluate BCG vaccination recommendations for healthcare personnel In 2014, 5 years after routine adolescent BCG vaccination was discontinued, the first cohort of unvaccinated individuals started healthcare studies. Practical difficulties related to BCG vaccination of healthcare employees and students had been anticipated, and indeed soon appeared. A main obstacle was

Association of the past epidemic of Mycobacterium tuberculosis with mortality and incidence of COVID-19

“…† Information was obtained from the BCG World Atlas [18]. Norway was moved from groups A to B [19]. The P-values shown above the bar were calculated using Bonferroni adjusted t-test.…”

“…C: The country never had universal BCG vaccination programmes. Norway was moved from groups A to B [19]. TB, tuberculosis.…”

“…We classified the targeted countries into three groups according to the status of BCG vaccination in 2011, using the BCG World Atlas [18]; group A: The country, currently, has a universal BCG vaccination programme, group B: The country used to recommend BCG vaccination for everyone, but currently, it does not, and group C: The country never had universal BCG vaccination programmes. Because Norway stopped universal BCG vaccination in 2009 [19], the group was moved from groups A to B in this analysis.…”

Association between past tuberculosis epidemic and COVID-19-related mortality through latent infection by natural immunity

“…For example, Norway terminated universal BCG vaccination in 2009, mainly due to a very low incidence of tuberculosis. 17 Therefore, although Norway had been classi ed as group A in 'the BCG World Atlas' in 2011 10 , the group is virtually moved from groups A to B in the analysis. It is obvious that the past tuberculosis epidemic is the strong determinant that precedes preventive policy for tuberculosis including vaccination.…”

“…We classi ed the targeted countries into three groups according to the status of BCG vaccination in 2011, using the BCG World Atlas; 10 group A: The country, currently, has a universal BCG vaccination programme, group B: The country used to recommend BCG vaccination for everyone, but currently, it does not, and group C: The country never had universal BCG vaccination programmes. Because Norway stopped universal BCG vaccination in 2009, 17 the group was moved from groups A to B in this analysis.…”