ABO Blood Groups and Incidence of COVID-19 in the Mass Gathering Events in Borriana (Spain), March 2020: A Retrospective Cohort Study

Abstract

Our objective was to estimate the incidence of COVID-19 and the ABO blood Groups in the mass-gathering events (MGEs) during the Falles Festival in Borriana (Spain) from 6–10 March 2020. We conducted a population-based retrospective cohort study and measured anti-SARS-CoV-2 antibodies and the ABO of participants. We performed laboratory COVID-19 tests and obtained the ABO in 775 subjects (72.8% of the original exposed cohort): O-group (45.2%), A-group (43.1%), B-group (8.5%) and AB-group (3.4%). Adjusted for confounding factors, including COVID-19 exposure during the MGEs, attack rates of COVID-19 for each ABO group were 55.4%, 59.6%, 60.2%, and 63.7%. The adjusted relative risks were for O-group 0.93 (95% Confidence Interval [CI] 0.83–1.04), for A-group 1.06 (95% CI 0.94–1.18), for B-group 1.04 (95%CI 0.88–1.24), and for AB-group 1.11 (95% CI 0.81–1.51) with no significant differences. Conclusions: Our results suggest no effect of ABO on COVID-19 incidence. We observed weak but not significant protection of the O-group and not a significantly greater infection risk for the remaining groups compared with the O-group. More studies are needed to resolve the controversies regarding the association between ABO and COVID-19.

Association between ABO blood type and coronavirus disease 2019 severe outcomes across dominant variant strains

“…In one systematic review and meta‐analysis, results indicate that the COVID‐19 infection rate was higher in persons with blood group A > O > B > AB 35 . In another study conducted in Spain, there was no significant association between ABO blood type and the development of infection 36 . Such variations in findings across studies emphasize the need for comprehensive and well‐controlled investigations to tease apart the true nature of the association.…”

Association of ABO blood types and clinical variables with COVID-19 infection severity in Libya

“…Although many have used big sample sizes to illustrate the presence of a clear link, 3–6 several other investigations have shown no connection between COVID-19 infection and blood types. 7–10 The ABO locus has been linked to genetic connections with both infection risk and disease severity. With the use of preliminary experimental data, certain fundamental hypotheses have been proposed to explain the found connections.…”

“…Although many have used big sample sizes to illustrate the presence of a clear link, [3][4][5][6] several other investigations have shown no connection between COVID-19 infection and blood types. [7][8][9][10] The ABO locus has been linked to genetic connections with both infection risk and…”

Incidence and Risk Factors of the COVID-19 Pandemic: An Epidemiological Approach

“…Four of the eight published manuscripts focused on high-risk groups in areas of society most affected by the pandemic: staff and residents in residential long-term care homes (LTCHs) for older people and patients with chronic mental illness [ 7 , 8 , 9 , 10 ]. The remaining manuscripts focused on the secondary rate of COVID-19 transmission in the families of healthcare workers [ 11 ], ABO blood groups as a potential risk factor for infection [ 12 ], post-COVID-19 complications [ 13 ], and new SARS-CoV-2 variants [ 14 ]. All of these studies were conducted before the vaccination program against SARS-CoV-2 began in January 2021.…”

“…ABO blood groups and SARS-CoV-2 incidence were studied during mass gathering events during the Falles festival of Borriana (Spain), but significant associations were not found [ 12 ]. Post-COVID-19 complications in these participants were studied during a 6-month follow-up; 33.1% experienced at least one complication, and 29.4% of the participants sought medical assistance [ 13 ]. Finally, potential new COVID-19 variants could change our approach to the virus, and current strategies must address these situations [ 14 ].…”