SAN FRANCISCO (KRON) – An increase in vaccinations combined with people previously infected with COVID-19 – both are working together to slow the spread of the disease.

That is longform for herd immunity.

There’s a lot of talk out there about San Francisco being on pace to be the first city in the U.S. to reach COVID-19 herd immunity, but what is the data telling experts?

“The data are telling me that we are pretty close. I think that 72% of the total population with at least one dose. We are quite near where we need to be. It’s all in the right direction and we are doing better than anyone else,” said Dr. George Rutherford, UCSF epidemiology professor.

Dr. Rutherford points to a key indicator – a dramatic decline in rates of hospitalizations.

“I think most recently there were 14-inpatients in all of San Francisco and 6 of them were from outside of San Francisco. So that’s pretty remarkable,” he added.

However, Dr. Rutherford cautions while this is maybe reason for celebration, he says it is not a pass for anyone thinking that herd immunity means San Franciscans no longer need to get vaccinated.

“Yeah negatory! First of all these variants keep getting more and more transmissible, which pushes the level for herd immunity up higher and higher. If you would have asked me a year ago I would have said 67% no questions asked. Now I am thinking maybe 75%, 78%, maybe 82%. We’re going to have to get it up there so we need everyone to get vaccinated,” said Dr. Rutherford.

Officials at the San Francisco Department of Public Health agree.

They sent KRON4 a statement reading in part:

“Although we are encouraged that San Francisco has very high vaccination rates, reaching a certain percentage of people immunized does not signify an end to COVID. There are some populations that continue to be susceptible to the virus, including communities that have lower vaccination rates as well as those people who are ineligible for vaccines, such as children below 12 years of age. Thus there is a need for ongoing vaccination efforts and closely tracking COVID cases.”

SF Dept. of Public Health

Herd immunity may be one reason to get vaccinated.

Dr. Rutherford says self-preservation is another reason.

“Think about getting this for yourself first. This is a nasty disease.”