Sure enough, a few people came running into the clinic at the last minute, saying they'd heard the announcement and wanted to get their shot.
"It was such a vindication of that particular approach and a verification that it worked," Romero said.
The truck may have been a new addition, but this type of grassroots, direct vaccine outreach is something the mayor has been championing for months in an effort to increase East Palo Alto's vaccination rate, including personally knocking on 3,000 doors.
Romero actually got the idea for the pickup truck announcements from a group of local high school students who also have been working on a door-to-door canvassing campaign. Over a dozen high schoolers have knocked on doors roughly 9,000 times, sometimes the same home more than once, as part of an effort organized by the nonprofit Youth Community Service (YCS).
When someone answers, the teens ask whether the person has been vaccinated, and if not, whether they'd be interested in getting a shot. They'll then share information about upcoming local vaccine clinics and answer any questions the resident might have.
"Instead of just posting a flyer, we actually walked up, knocked on the door, engaged (and) had a conversation," YCS Executive Director Mora Oommen said.
Palo Alto High School senior Fiorella Garcia-Rojas decided to take part in the outreach effort because she wanted to help people get vaccinated who might not otherwise have access to a shot, particularly Latino residents. Part of the reason Garcia-Rojas thinks people were comfortable talking with her was because she is Latina herself.
"It feels more like ... their own community coming to tell them information," Garcia-Rojas said.
Having people with whom residents identify do the outreach was an important part of the effort, Oommen said.
"Just that reassurance from somebody who looks like them and is from their own community, from our own community, really makes a difference," Oommen said.
People of color make up the overwhelming majority of East Palo Alto's population. According to the 2020 census, roughly two-thirds of East Palo Alto's residents are Hispanic. Only 7.7% are white.
According to Romero, local leaders realized early on that "high touch" outreach would be necessary to reach working class and low-income minority communities in the city.
Currently, 79.5% of those aged 10 and up in the city have received at least one vaccine dose, according to county data. That's much higher than it once was, but lower than nearby cities like Menlo Park, where the vaccination rate is 99%.
A broad coalition of local leaders, community groups, health care providers and others have come together under the banner of Umoja Health San Mateo County to expand access to vaccination, particularly in East Palo Alto, Belle Haven and North Fair Oaks. The door knocking campaign is one part of that effort.
Umoja Health San Mateo County was started in March by Kala Mehta, a Palo Alto resident and associate professor at UCSF in the department of epidemiology and biostatistics, and Lisa Tealer, the executive director of the Bay Area Community Health Advisory Council. The original Umoja Health chapter was founded in Oakland by Dr. Kim Rhoads, who is a colleague of Mehta's at UCSF.
"When she told her story about what was going on in Oakland, I recognized what was happening and knew that something very similar was happening in East Palo Alto," Mehta said.
Communities of color were not accessing vaccines at nearly the rates of the overall population, primarily due to a lack of availability in their local area, Mehta said.
Over 70 local leaders are now meeting weekly as part of Umoja Health San Mateo to collectively work on increasing vaccination rates.
"We needed to bring everyone together (and) have a forum for folks to talk and help coordinate," Tealer said.
Umoja uses a "for us, by us" model, Oommen said, where people within the community work collectively.
The group has focused on providing "radical convenience," Romero said, bringing accessible clinics right into the neighborhoods with the lowest vaccination rates.
One problem early on was that many vaccination events were held during the work day or at mass sites out of the area.
"Those kinds of larger events are really geared toward people with cars and computers," Tealer said.
Another issue was clinics asking for substantial documentation, which can be a barrier for many, especially undocumented residents. Umoja worked with health care providers to simplify the process.
"We don't want people to not get a shot because they mistrust the government or they mistrust a medical institution," Romero said.
By partnering with health care providers to offer convenient, low barrier clinics, Mehta said roughly 13,900 vaccine doses have been administered with Umoja Health's support. The plan is to expand Umoja Health's model to north San Mateo County, Tealer said.
Starting in March, Mehta helped organize a group of university students in a door-to-door outreach effort. Over the summer that transitioned into YCS' work with local high school students. They focused on the west side of the city, which had the lowest vaccination rate, Oommen said.
Weekly vaccine clinics were scheduled in the area and the students engaged individually with each person who opened the door, telling them about the clinics and often answering questions.
In some cases, people believed "outright falsehoods" about the vaccine that they saw on the internet, Romero said, like that it will make you sterile or enlarge your heart. The person doing the outreach generally tried to talk through those concerns, but they also encouraged the resident to talk to medical staff at a vaccine clinic.
Medical student Rayan Lotfi volunteered last week to take part in an "Ask a scientist" booth at a vaccine event in East Palo Alto, where he helped answer people's questions. In addition to sharing information about the vaccine, Lotfi said it also often helped to talk about his own experience getting vaccinated.
"It puts a more human face to the medical providers who are getting vaccinated and advocating for it," Lotfi said. He also talked about encouraging his own family and friends to get vaccinated.
Often though, he didn't so much have to combat misinformation as ensure people knew about the clinics and felt comfortable accessing them.
In one case, Palo Alto High School junior Angel Solorio was walking down the street and saw a man standing nearby. Solorio asked the man in Spanish whether he'd been vaccinated, and when he said no, offered to walk with him to a nearby vaccination clinic. He took Solorio up on the offer, saying that he'd seen the clinic already but had heard a lot of people talking in English, so he didn't go in.
"Since I came to him talking in Spanish and he only (spoke) Spanish, I feel like he felt more comfortable," Solorio said.
The canvassers would also often go to the same house multiple times, including on the day of a clinic, letting residents know there were nearby options to get vaccinated.
"That's what we were trying to get across — this is happening right here for you," Oommen said. "You don't need to go far. You don't need an appointment. There are no questions asked."
The last in a series of Saturday clinics that have been running at the Woodland Park apartment complex in East Palo Alto was held last Saturday. For information on other clinics in San Mateo County, visit smchealth.org/vaccine-clinic-calendar.