Researchers testing effectiveness of third Pfizer shot
By Caleb Hampton McNaughton Media Researchers at UC Davis Health are conducting trials to test the effectiveness of a third dose of Pfizer’s COVID-19 vaccine. The trial comes amid a sharp rise in cases resulting from the highly transmissible delta variant and warnings from the Centers for Disease Control and Prevention that people who received the standard one or two-dose vaccines can still transmit the virus without developing symptoms themselves. Timothy Albertson, the UC Davis Health researcher leading the trial, described it as an extension of earlier trials of the Pfizer vaccine conducted at UC Davis beginning last year. The booster shot trial will involve the same participants, who previously received either two doses of the Pfizer vaccine or a placebo. Participants who were vaccinated will now be randomly given either a third vaccine dose or a dose of a placebo. UC Davis Health researchers will measure participants’ antibodies over time and track breakthrough cases of COVID-19. Participants in the trial were selected due to their diversity in age, race and sex, the health system reported. UC Davis Health is just one site in a worldwide trial involving 40,000 participants. “[The virus] is a wily beast that is not going to go away by just wishing it,” Albertson told CBS Sacramento. “We did not get herd immunity despite our best efforts.” A recent study conducted by Pfizer found that the vaccine’s effectiveness may weaken over time and that a third shot boosts protection from the virus, the company reported last week. Meanwhile, researchers say more data needs to be collected before a third shot is advised for the general public. “There’s not enough evidence right now to support that that is somehow the best use of resources,” Natalie Dean, a biostatistician at Emory University in Atlanta, told The New York Times. In the long run, Albertson said he thinks it is likely people will get yearly COVID-19 vaccines the same way that we get flu shots every year, especially if the virus continues to mutate into new variants. “We’re seeing more and more evidence is this is not going away,” he told KCRA 3. “When we have rapid changes in the virus, it’s not hard to imagine that we will find variants that are not covered eventually.” The best way to prevent the virus from continuing to spread and mutate, he said, is to get people vaccinated, especially those who haven’t yet received a first dose. “The risk-benefit ratio [of getting vaccinated] is so clear,” said Albertson, who has treated COVID-19 patients in UC Davis Health’s intensive care units. While more than half of U.S. adults have been vaccinated against COVID-19, those individuals comprise less than 1 percent of COVID-19 related deaths, according to recent government data.