A team from San Mateo County Health's Street and Field Medicine vaccinates individuals experiencing homelessness at a clinic at a church in San Bruno, Calif. on March 25, 2021. (Photo courtesy the County of San Mateo Joint Information Center)

Since COVID-19 vaccinations for 12- to 15-year-olds began in San Mateo County last Thursday, over 5,000 youths in that age group have received their first dose.

The exact number vaccinated is 5,351 individuals, or 13 percent of the county’s population in that age group, officials said Tuesday during a meeting of the San Mateo County Board of Supervisors.

Dr. Anand Chabra, San Mateo County Health COVID-19 mass vaccination section chief, said there was great enthusiasm around vaccinations when eligibility opened up for adolescents last week.

“We immediately saw very positive engagement in our events and many pharmacies throughout the county,” Chabra said. “We have been working very closely with the San Mateo County Office of Education to create pathways to the vaccine for these 40,152 adolescents and their families.”

Individuals 12 to 15 years old are eligible for the Pfizer vaccine at the county’s mass vaccination sites and community clinics.

Stanford Health Care already operates a clinic at the Cesar Chavez Ravenswood Middle School in East Palo Alto, where residents 12 and older can receive vaccines.

Chabra said the county is working with other high schools and places of worship to create additional vaccine opportunities. This past Sunday, Chabra said 114 people were vaccinated at St. Francis of Assisi Church in East Palo Alto.

“We recognize we’ve still got a long way to go,” Chabra said. “Reaching many of the residents requires sustained approaches. Now with the vaccine flowing, we can provide a regular cadence of predictable, scheduled local clinics.”

As of Monday, 78 percent of San Mateo County residents 16 and older have received at least the first dose of the COVID-19 vaccine. In the county’s hardest-hit communities, 66 percent of residents have been vaccinated.

In response to a question about when the county could reach herd immunity, Chabra said there is no definitive number for when that is achieved.

Chief of San Mateo County Health Louise Rogers added that health experts are aiming to get more than 80 percent of the population vaccinated.

But even as more people in the county and the nation get vaccinated, Rogers said that many people around the world have not had the same vaccine access.

“The reality is that until everyone on the planet is able to access the vaccine, it’s going to be difficult with such a mobile society, especially in urban areas, really to fully get there,” Rogers said. “The good news is that the vaccines have been so effective at absolutely stopping the spread of the disease and the hospitalizations and so on.”

Rogers said that the county is tracking coronavirus variants, particularly the one known as the B117.

The county has also had breakthrough cases, which occur when a fully vaccinated person gets COVID-19 two weeks or longer after full vaccination. Rogers said the number of breakthrough cases has been “consistent with what has been expected from the beginning” and not any more than expected.

Regarding mask wearing, Rogers said San Mateo County will continue to align with the state’s mask guidance — available at https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/COVID-19/guidance-for-face-coverings.aspx.

Currently, Californians are required to wear masks indoors. Fully vaccinated people can go without a mask outdoors, except in crowded settings.

The state expects to update its guidance on June 15 to align with the federal Centers for Disease Control and Prevention.

“But there’s many weeks between now and June 15,” Rogers said. “And as you all know, many things can change as we’ve seen.”

A list of vaccine clinics in San Mateo County is available at https://www.smchealth.org/vaccine-clinic-calendar. People do not have to schedule an appointment but can do so at MyTurn.ca.gov if they wish.