Stanford epidemiologist explains how effective the COVID-19 vaccine really is

SAN FRANCISCO -- With so much reporting on the Delta variant and breakthrough COVID-19 cases, you may be wondering whether the vaccine really works.

Health officials say they are certain about at least one thing when it comes to COVID-19 vaccinations.

"If you're vaccinated you're much less likely to develop COVID," said Jorge Salinas, hospital epidemiologist at Stanford University.

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"We have data from multiple parts of the world, the United Kingdom, Israel and the United States that most cases of COVID associated with the Delta variant are happening among people who are not fully vaccinated," Dr. Salinas said. "It is true there have been some cases reported in those who are fully vaccinated but the odds are completely different, are much lower. You're much less likely to develop COVID if you're fully vaccinated and if you develop COVID, it's going to be milder than if you were not vaccinated."

In the Bay Area both total hospitalizations and ICU numbers are down as compared to last year.

According to state data analyzed by ABC7 News data journalists, total hospitalizations are down by about 13 percent when comparing July 31, 2021 to July 31, 2020. ICU numbers are down by about 30% when comparing the same dates.

Dr. Salinas says he believes it's too early to know how the rest of the year could play out when it comes to the Delta variant.

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"I don't think we can judge yet what the impact will be of this new surge in the Bay Area," said Dr. Salinas.

Still he hopes the evidence available in terms of decreased hospitalizations and ICU cases will be enough to encourage everyone to get vaccinated.

"It is the right thing to do for your own health it is the right thing to do for the population's health, for all of us. We're all in this together," said Dr. Salinas.

CDC COVID-19 Transmission Categories by California County

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