CDC projects 'sharp decline' in Covid-19 cases by July

10 May 2021

The United States could see a drop in Covid-19 cases and deaths by July if vaccinations remain high and people adhere to certain prevention measures, a new modeling study suggests.

But if fewer people follow Covid-19 precautions (such as wearing masks and physical distancing) it could undermine the gains from vaccinations to slow the spread of the coronavirus in the United States.

The study, published by the US Centers for Disease Control and Prevention, projects that with high immunization coverage and a moderate adherence to prevention measures, Covid-19 hospitalizations and deaths will likely remain low nationally and sharply decline by July.

But accelerating declines in adherence to prevention measures in combination with increased transmissibility of new variants "could lead to surges in cases, hospitalizations, and deaths", even with improved vaccination coverage, researchers from the CDC and various US institutions wrote in the report.

The study makes clear that the sooner the US gets more people vaccinated, the sooner the nation could return to normal, but coronavirus variants are a "wild card," according to CDC Director Dr. Rochelle Walensky.

For the study, six modeling research teams estimated what the future of the pandemic could look like in the United States from April to September of this year. The teams developed models to project weekly reported Covid-19 cases, hospitalizations, and deaths using data from Johns Hopkins University and federal databases.
The models included four scenarios where there were: rates of high vaccination with moderate adherence to prevention measures; high vaccination with low adherence to measures; low vaccination with moderate adherence to measures and low vaccination with high adherence to measures.

The researchers found that all four scenarios project an increase in Covid-19 cases at the national level through April, peaking in May, and then declining by July. But the models showed that if people just moderately follow prevention measures it could reduce cases and deaths in both high- and low-vaccination scenarios, compared with low adherence to measures.
The findings provide only estimates of the future and are limited to six models.