COVID-19 Due to Wild-Type SARS-CoV-2 More Prevalent in Adolescents and Youth than in Older Adults Based on 19 US States in Fall 2020 Prior to Vaccine Availability

ABSTRACT

PURPOSEIn a prior study, we examined data from six US states during Summer 2020, and found that prevalence of COVID-19 for adolescents and youth was significantly greater than for older adults (p<.00001) as was a prevalence-related measure: Number of cases observed / Number of cases expected (p<.005). We now extended our study to more states in Fall 2020 to confirm the prevalence relationships we found previously. Vaccines were still not available as of Fall 2020. Presumably, the SARS-CoV-2 strain circulating at the time was the wild-type lineage since no variants were reported in the US until the end of December 2020. METHODSWe examined data from 19 U.S. states experiencing surges in cases to determine prevalence of COVID-19, and a prevalence-related measure: [Number of cases observed in a given age group] / [Number of cases expected in the age group based on population demographics]. RESULTSIn 16 of the 19 states, we found that (1) prevalence of COVID-19 for adolescents and youth was significantly greater than for older adults (p-values ranged from p<0.00001 to p = 0.0175; (2) the ratio of cases observed to cases expected was significantly greater in adolescents and youth than in older adults (p-values ranging from p< 0.00001 to p = 0.004). CONCLUSIONSOur results are consistent with our previous study in Summer 2020. The finding of lower prevalence in older adults cannot be attributed to access to vaccination since our data are from Fall 2020 when vaccinations were not yet available. Our findings with the SARS-CoV-2 wild-type strain are consistent with the findings currently being reported in the UK for the delta variant. In both studies, prevalence in adolescents and youth exceeded that in older adults. The UK findings are more pronounced perhaps because that study transpired following months of vaccinations of older adults whereas ours occurred before vaccinations were available.