Can polio vaccines induce cross-reactive antibodies that target SARS-CoV-2?
Among the interesting aspects of the current pandemic of coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) is the clear selectivity of its pathogenicity. .. Toddlers usually escape the serious or life-threatening traits of infection compared to adults over the age of 60. A new study, led by researchers at Johns Hopkins University in the United States, is investigating the link between immunity to SARS-CoV-2, former SARS-CoV, and pediatric poliovirus vaccination. Almost 90% of the worlds people are vaccinated with this vaccine, but the antibodies induced by it decrease over time and are almost non-existent at the end of adolescence. The preprinted version of the study medRxiv* Servers and articles have been peer reviewed. Background  Some early studies have shown that certain vaccines have cross-protective properties. Effectiveness Not only for the specific viruses they created, but also for viruses that are structurally similar. This is true for poliovirus and mumps vaccines, with one report showing that susceptibility to SARS-CoV-2 and severity of COVID-19 are inversely correlated with mumps antibody titers. Both poliovirus and SARS-CoV-2 contain single-stranded ribonucleic acid (RNA) molecules as genetic material, and all proteins are translated directly from this template strand. During both viral replications, the genome is replicated from this strand using the synthesized RNA-dependent RNA polymerase (RdRp) protein. The RdRp enzyme is the basis of viral replication, and multiple screens have been attempted to block its activity and neutralize the virus. Researchers in this study explain:Structural similarities in RdRp of all single-strand plus RNA viruses may explain the cross-reactivity of polio immune serum with the SARS-CoV-2 antigen...   Two types of polio vaccines are used worldwide. One is the live attenuated polio vaccine (OPV) and the other is the inactivated poliovirus vaccine (IPV). Concerns about the potential return to wild-type paralytic poliovirus have led to the discontinuation of OPV in the United States, where IPV is universally administered. Not only is the latter associated with high efficacy, but the vaccine-derived poliovirus (VDPV) cannot escape to the environment and has few side effects. Researchers intend to test their theory that age-dependent morbidity and mortality with COVID-19 is mediated by immunity to viruses that are partially contributed by poliovirus vaccination. Was there. Using data from the top 100 countries infected with the virus, we found that the higher the median age, the higher the prevalence of the virus and the higher the mortality rate from COVID-19 in that country. Second, they found that RdRp from SARS-CoV-2 and poliovirus had similar tertiary and quaternary structures and a similar molecular weight of about 130 kD. Both were bound to one site by at least the mouse anti-RdRp monoclonal antibody 4E6. Researchers have discovered anti-RdRp antibodies in both adult and child samples and were able to recognize RdRp from both viruses. Higher titers were seen in those who received IPV. Immune sera from these individuals inhibited viral replication in Vero cells, and stronger effects were observed when antisera were added to the cells prior to viral attack. The strongest inhibition was seen with antisera from fully immunized infants and young adults. If poliovirus vaccination builds immunity to the new coronavirus, the child will be fully vaccinated by the age of one, but not four months, so these results are expected. The same effect is seen when adults are immunized with two IPVs, inducing a stronger inhibition of the SARS-CoV-2-induced cytopathic effect (CPE) in cell culture. Protection from either polio or SARS-CoV-2 decreases with age, but inhibition of CPE is improved by more than one-third with a single dose of IPV booster. The weakened immunity of adults aged 60 to 65 years may be partially compensated by IPV, surpassing the immunity of recently unvaccinated adolescents. In vitro inhibition of RdRp activity was observed with poliovirus antisera randomly selected from immunized adults and children, with 13 of 17 samples showing effective inhibition of RdRp enzyme activity. According to the survey, Poliovirus vaccination produces antibodies that cross-react with SARS-CoV-2. The main targets of these antibodies are poliovirus and coronavirus RdRp... Antisera from immunized individuals prevent SARS-CoV-2CPE in cell culture. Antisera normally reduced RNA replication by inhibiting RdRp activity. These findings may suggest that childhood vaccination elicited antibodies to SARS-CoV-2 in young individuals and thus reduced their susceptibility to the virus. This is in line with studies showing the potential role of anti-tuberculous BCG, MMR (targeting measles, mumps, rubella) and poliovirus vaccines in protection from SARS-CoV-2 infection. The study also highlights the potential importance of RdRp as a therapeutic target. Anti-RdRp antibodies clearly inhibit SARS-CoV-2CPE by preventing adsorption or internalization to host cells mediated by the interaction of the viral genome with RdRp. Therefore, SARS-CoV-2 protein antigens other than immune-dominant spikes may be suitable for vaccine development. IPV immunity suggests that it may elicit adaptive, generally long-term specific immunity against poliovirus and SARS-CoV-2 infections... The authors continue to investigate through larger clinical trials to test the usefulness of this vaccine in the prevention of COVID-19. The poliovirus vaccine is a decade-old vaccine with a wealth of safety data and established pharmacological standards, so the potential is bright. Manufacturing and toxicity data are also readily available. In light of the serious vaccine hesitation and lack of vaccine supply for the newly developed COVID-19 vaccine, researchers suggest revisiting the usefulness of poliovirus vaccines from this perspective. *Important Notices  medRxiv Publish preliminary scientific reports that should not be considered definitive as they are not peer-reviewed, guide clinical practice / health-related behaviors, and should not be treated as established information.