The impact of smoking on immunological response to SARS-COV 2: a nationwide seroepidemiological study

Abstract Background Smoking influences cellular and humoral immune responses and affects the immune system by increasing inflammation and decreasing activity against infections. The current study investigates the association between smoking and immunological response to SARS-CoV-2 in the Armenian population. Methods We performed a nationwide cross-sectional seroepidemiological study among the adult population (≥18 years old) in Armenia. We used a multi-stage cluster random sampling to recruit participants from the capital city and all regions of Armenia. We invited selected participants to primary healthcare facilities to provide blood samples for antibody testing followed by a phone survey on demographic characteristics, smoking status, and other variables. Logistic regression analysis was used to test the relationship between smoking and having SARS-CoV-2 antibodies adjusted for other covariates. Results 3483 people participated in the study (71% women). The total sample included 16.8% current smokers (n = 571), 8.6% past smokers (n = 294) and 76.4% never smokers (n = 2538). The prevalence of SARS CoV-2 antibodies among current smokers was statistically significantly lower as compared with never smokers (46.9% vs 73.4%, p-value<0.001). In the multivariable logistic regression model, the odds of having SARS CoV-2 antibodies among the current smokers was 70% lower (OR 0.30, 95%CI: 0.22; 0.40) compared to never smokers, when adjusted for demographic factors and the time of PCR diagnosis of COVID-19. No statistically significant difference was found between past smokers and having SARS CoV-2 antibodies. Conclusions In addition to being a risk factor for various chronic diseases, smoking weakens immune response to infectious diseases, including COVID-19, worsening the outcomes. The significantly lower level of antibody prevalence among smokers with previous PCR confirmed COVID 19 implies a poorer immune response to the infection and not a lower risk of getting the infection. Key messages • Smoking weakens immune response and contributes to a higher burden of infectious diseases, such as COVID-19. • Lower level of antibody prevalence among smokers indicates a poorer immune response to the infection rather than a lower risk of getting the infection.


Background:
Smoking influences cellular and humoral immune responses and affects the immune system by increasing inflammation and decreasing activity against infections. The current study investigates the association between smoking and immunological response to SARS-CoV-2 in the Armenian population.

Methods:
We performed a nationwide cross-sectional seroepidemiological study among the adult population (!18 years old) in Armenia. We used a multi-stage cluster random sampling to recruit participants from the capital city and all regions of Armenia. We invited selected participants to primary healthcare facilities to provide blood samples for antibody testing followed by a phone survey on demographic characteristics, smoking status, and other variables. Logistic regression analysis was used to test the relationship between smoking and having SARS-CoV-2 antibodies adjusted for other covariates. Results: 3483 people participated in the study (71% women). The total sample included 16.8% current smokers (n = 571), 8.6% past smokers (n = 294) and 76.4% never smokers (n = 2538). The prevalence of SARS CoV-2 antibodies among current smokers was statistically significantly lower as compared with never smokers (46.9% vs 73.4%, p-value<0.001). In the multivariable logistic regression model, the odds of having SARS CoV-2 antibodies among the current smokers was 70% lower (OR 0.30, 95%CI: 0.22; 0.40) compared to never smokers, when adjusted for demographic factors and the time of PCR diagnosis of COVID-19. No statistically significant difference was found between past smokers and having SARS CoV-2 antibodies.

Conclusions:
In addition to being a risk factor for various chronic diseases, smoking weakens immune response to infectious diseases, including COVID-19, worsening the outcomes. The significantly lower level of antibody prevalence among smokers with previous PCR confirmed COVID 19 implies a poorer immune response to the infection and not a lower risk of getting the infection.

Key messages:
Smoking weakens immune response and contributes to a higher burden of infectious diseases, such as COVID-19. Lower level of antibody prevalence among smokers indicates a poorer immune response to the infection rather than a lower risk of getting the infection.

Background:
Exploring treatment burden at a population level can provide evidence of the types of patients who need special attention and support. We aimed to determine factors associated with high perceived treatment burden in a population-based survey of adults living in the Central Denmark Region (23% of the Danish population).

Methods:
The Danish Multimorbidity Treatment Burden Questionnaire (MTBQ) was included in the 2017 Danish population health survey. 28,627 individuals aged 25 years or over participated (64% response rate). Individuals who reported having one or more medical conditions or attending regular health check-ups were asked to complete the MTBQ. A global MTBQ score was calculated (range 0-100) and both the continuous scores and a four-category grouping of the scores into no, low, medium and high burden were used to statistically assess the association between treatment burden and sociodemographic and healthrelated factors. Results: 13,407 individuals completed the Danish MTBQ (mean age 59 years). Treatment burden was negatively associated with selfrelated health (rs = -0.45, P < 0.0001), health-related quality of life (rs = -0.46/-0.51, P < 0.0001) and positively associated with the number of long-term conditions (rs = 0.26, P < 0.0001) and perceived stress (rs = 0.44, P < 0.0001). Higher treatment burden was associated with young age, male sex, high educational level, unemployment, not living with a spouse/cohabitant, living with child(ren) and specific long-term conditions, including heart disease, stroke, diabetes and mental illness.

Conclusions:
This is the first known population-based study of treatment burden. The findings provide important evidence to policy makers and clinicians about sociodemographic groups at risk of higher treatment burden. We recommend that patientperceived treatment burden is included when evaluating iii470 European Journal of Public Health, Volume 32 Supplement 3, 2022