COVID-19 in children: Could pertussis vaccine play the protective role?

Abstract

While COVID-19 continues to spread across the globe, diligent efforts are made to understand its attributes and dynamics to help develop treatment and prevention measures. The paradox pertaining to children being the least affected by severe illness poses exciting opportunities to investigate potential protective factors. In this paper, we propose that childhood vaccination against pertussis (whooping cough) might play a non-specific protective role against COVID-19 through heterologous adaptive responses in this young population. Pertussis is a vaccine-preventable infectious disease of the respiratory tract and it shares many similarities with COVID-19 including transmission and clinical features. Although pertussis is caused by a bacterium ( Bordetella pertussis ) while COVID-19 is a viral infection (SARS-CoV-2), previous data showed that cross-reactivity and heterologous adaptive responses can be seen with unrelated agents of highly divergent groups, such as between bacteria and viruses. While we build the arguments of this hypothesis on theoretical and previous empirical evidence, we also outline suggested lines of research from different fields to test its credibility. Besides, we highlight some concerns that may arise when attempting to consider such an approach as a potential public health preventive intervention against COVID-19.

Pneumococcal and Influenza Vaccination Rates and Pneumococcal Invasive Disease Rates Set Geographical and Ethnic Population Susceptibility to Serious COVID-19 Cases and Deaths

“…The results reported here add to the literature reviewed in the Introduction that cast doubt on studies reporting that BCG, polio, or DPT vaccinations may protect against COVID-19 acquisition or death [64][65][66][67][68][69][70][71][72][73][74][75][76]. However, one important caveat must be mentioned, which is that it was not possible in this study to differentiate between nations using acellular pertussis vaccines, those using whole-cell pertussis vaccines, and those using both as part of their vaccination programs.…”

“…Finally, diphtheria-tetanus-pertussis vaccination [ 74 , 75 , 76 , 77 ] and polio vaccination [ 78 ] have also been suggested as possible prophylactics against COVID-19, but at present, no ecological study exists to support these possibilities. Published studies have found no protective benefit [ 5 , 44 , 45 ], and antibody titers against tetanus do not correlate with COVID-19 protection [ 48 ].…”

Diphtheria And Tetanus Vaccination History Is Associated With Lower Odds of COVID-19 Hospitalization

“…The tuberculosis vaccine Baccilus Calmette-Guérin (BCG) has been studied in this context, as it is known to generally boost the innate immune response and reduce respiratory tract infections ( 9 ), with some studies finding a relation between BCG national vaccination programs and COVID-19 mortality rates ( 10 ), although there have also been studies that have discarded the protective effects of BCG vaccinations ( 11 ). Several other vaccines may ready the immune response with partial specificity, and thereby produce protective effects ( 12 – 14 ). Indeed, there appear to be sequence similarities between proteins in pathogens targeted by common vaccines and SARS-CoV-2 ( 14 – 16 ); e.g.…”

Value of Immunizations during the COVID-19 Emergency

“…Others argue that whooping cough is a vaccine-preventable infectious disease of the airways and shares many similarities with COVID-19, including transmission mode and clinical features. Although pertussis is caused by a bacterium ( Bordetella pertussis ) while COVID-19 is a viral infection (SARS-CoV-2), some data seem to support that cross-reactivity and heterologous adaptive responses can also be observed among unrelated agents such as between bacteria and viruses [ 32 ].…”