San Diego County officials and local infectious disease experts are asking fully vaccinated residents to get booster shots now to limit an expected uptick in coronavirus cases and hospitalizations this winter.
The message comes with the holiday season fast approaching. Experts worry that increased travel and indoor gatherings could spark yet another COVID-19 surge, including among vaccinated people whose immunity has waned.
Boosters are meant to help avoid that scenario, but public officials say that not enough people have been getting the shots.
“This time period is more critical than ever,” said Dr. Seema Shah, director of the county’s epidemiology department. “If you deem yourself to be at risk, and you’ve been fully vaccinated, get a booster.”
Shah welcomed an announcement from the state’s public health department this week, which updated its guidelines to offer boosters to anyone who got their second dose of the Pfizer or Moderna vaccines at least six months ago or the Johnson & Johnson vaccine two or more months ago. The state’s initial booster messaging closely hewed to a complicated set of Centers for Disease Control and Prevention guidelines that offered boosters to the fully vaccinated depending on age, medical history or work or living circumstances.
Dr. Mark Ghaly, the state’s secretary of health and human services, said during a press briefing on Wednesday that no fully vaccinated Californian who seeks out a booster will be turned away.
Nearly 280,000 San Diegans have already gotten boosters, according to data posted this week on the county’s vaccine dashboard, though that figure includes some residents who got an additional shot because they are immunocompromised. The California Department of Public Health estimates that about 1.6 million San Diegans are eligible for boosters based on when they got their initial shots, meaning that around 18 percent of the eligible population has gotten a booster. That’s nearly identical to the statewide booster rate, according to data provided by the state’s public health department to the Union-Tribune on Tuesday.
Slightly more than half of the county’s booster recipients are 65 and older, a group public health officials have strongly encouraged to get these shots. Seniors have accounted for roughly 80 percent of COVID-19 deaths in the U.S., according to the CDC.
There are more than 300 vaccine sites region-wide where San Diegans can get boosters, including a mix of pharmacies, county-run locations and local health systems. Scripps Health, one of the region’s two largest health systems, has offered boosters to staff and patients at the Del Mar Fairgrounds. But Scripps will shut down the site after Nov. 30 in large part due to low demand for additional doses.
“We have been messaging and messaging, through MyScripps (and) on social media,” said Dr. Ghazala Sharieff, chief medical officer of clinical experience and excellence at Scripps. “We’re not getting as much of an uptick as I would have hoped for,”
She notes that the nearly 10,400 boosters the health system has doled out pale in comparison to the many thousands who lined up for vaccine early this year.
Researchers and public health officials believe confusion over eligibility has kept many people from coming forward. That’s because CDC guidelines for booster shots are riddled with caveats and ambivalent language on who should get boosters versus who may do so.
UC San Diego public health expert Dr. Chip Schooley was never a fan of the original messaging.
“By making it complicated, you both confuse people about whether booster vaccinations are actually needed, and you also make it more complicated for the health care system trying to turn people away who are only 64, under 5 feet 2, on an even-numbered day with blonde hair,” he said. “It just gets to be crazy.”
The county and local vaccine providers never turned down anyone who wanted a booster, Shah says. But she, too, prefers the state’s new simpler, clearer guidance.
Booster shots work by kicking immune responses sparked by the initial shots back into gear. That’s because while most of the immune cells that respond to an infection or vaccination eventually die, a few stick around. These cells, known as memory cells, are ready to launch a swift counterattack in case you’re ever exposed to a virus a second time.
A growing chorus of studies show that initial vaccine effectiveness wanes after several months. That includes a recent study of nearly 800,000 U.S. veterans published in the journal Science. Researchers found that vaccine effectiveness against coronavirus infection dipped from 89 and 87 percent in March for Moderna and Pfizer, respectively, to 58 and 43 percent by the end of September. The drop was more drastic for Johnson & Johnson’s vaccine, with protection against infection dipping from 86 to 13 percent in that same time.
Most severe COVID-19 cases continue to affect people who aren’t fully vaccinated. Over the past month, 91 percent of hospitalizations and 74 percent of coronavirus deaths in San Diego County have been among those who aren’t fully immunized. Nearly 600,000 San Diegans eligible for shots have yet to get them, though that includes more than 300,000 children 5 to 11 who just became eligible in early November.
Some critics have pointed to such numbers as evidence that boosters aren’t necessary. But Schooley warns that waiting for breakthrough cases to turn into a surge of hospitalizations among the vaccinated would be irresponsible. And he points out that boosters aren’t just about preventing severe disease. Leaving the virus with fewer hosts to infect reduces its spread and its chances to mutate in ways that could render current vaccines ineffective, though he thinks the latter scenario is unlikely.
Schooley’s optimistic that we won’t have to get boosters as often in the future. That’s because researchers like Shane Crotty of the La Jolla Institute for Immunology and others have found that the current vaccines seem to spark strong immune memory responses. Re-activating these cells with another shot should lead to a robust, longer-lasting immune response than what you had the first time. And that’s part of why Schooley, who’s already gotten a booster, is comfortable traveling to Virginia next week to visit family.
“We’re headed for the holiday and travel season,” he said, adding that the more people that get out there and get vaccinated, the less the virus will travel with us.