SARS-CoV-2 antibody response among COVID-19 patients is not affected by parasite co-infection

Background B-cell hypo-responsiveness has been associated with intestinal parasitic co-infection. The effect of parasite co-infection on antibody response to SARS-CoV-2 is unknown. Here, we aimed to determine antibody response to SARS-CoV-2 among COVID-19 patients co-infected with intestinal parasites and those without parasite co-infection. Methods In this prospective cohort study, a total of 589 samples were serially collected from 72 RT-PCR-confirmed patients. Anti-SARS-CoV-2 nucleocapsid protein (NP) antibody titers were measured longitudinally during hospitalization. SARS-CoV-2 infection was confirmed by RT-PCR on samples obtained from nasopharyngeal swabs, while direct microscopic examination, modified Ritchie concentration, and Kato-Katz methods were used to identify parasites and ova from fresh stool samples. Data were analyzed using STATA version 14. Results Of the 72 COVID-19 patients, 39 (54.2%) were co-infected with intestinal parasites while 33 (45.8%) had no parasitic co-infection. Overall, the median cut-off index (COI) for anti-NP antibody titer among COVID-19 patients co-infected with parasites was 6.91 (IQR: 0.55-40.7) compared to 7.51 (IQR: 0.21-59.21) in those without parasites (p=0.764). In addition, 174/261 [66.7% (95% CI: 60.68-72.16)] and 231/328 [70.4% (95% CI: 65.23-75.14)] specimens from COVID-19 patients with parasite co-infection and without parasites, respectively, had anti-SARS-CoV-2 antibody above the cut-off COI value (p=0.328). The positivity rate for anti-SARS-CoV-2 NP < 14 days after symptom onset was 66.3% (95% CI: 60.21-71.85) and 70.0% (95% CI: 64.72-74.74) for those not infected and co-infected with parasites, respectively (p=0.343). In addition, 31/72 (41.9%) of the patients who were negative at the time of enrollment were seroconverted. The trend in anti-NP antibodies among seroconverted individuals with and without parasites is also similar. Conclusions Co-infection with parasitic infection has very little effect on the anti-SARS-CoV-2 antibody immune response. Further studies on the profile of neutralizing antibodies in parasite-endemic areas are warranted to ascertain vaccine efficacy. Author’s summary Pre-existing co-infection with intestinal parasites has been shown to diminish antibody response to a multitude of heterologous pathogens or vaccines. However, the effect of parasite co-infection on antibody response to SARS-CoV-2 is unknown. We determined the anti-nucleocapsid protein (NP) antibody response to SARS-CoV-2 among COVID-19 patients co-infected with intestinal parasites and compared their response to those without parasites. There was no difference in anti-NP positivity rate, seroconversion, or titer level among COVID-19 patients with or without parasitic co-infection. Further studies on the profile of neutralizing antibodies in parasite-endemic areas are warranted to ascertain vaccine efficacy. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement DW, Clinicaltrials.gov: [NCT04473365][1] European and Developing Countries Clinical Trials Partnership(EDCTP). https://www.edctp.org/ No, ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study protocol was reviewed and approved by the Health Research Ethics Review Committee (HRERC) of Mekelle University College of Health Sciences (#ERC 1769/2020). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All relevant data are within the manuscript and its Supporting Information files. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT04473365&atom=%2Fmedrxiv%2Fearly%2F2023%2F08%2F21%2F2023.08.20.23294345.atom