Public health officials in Sonoma County on Tuesday revealed that 39 people in the country were so-called ‘breakthrough’ COVID cases, meaning they were infected with the coronavirus more than two weeks after they shot their second vaccination.
But UCSF expert infectious diseases, dr. Peter Chin-Hong, warns that this is an expected development and that it should not be considered bad news. As he tells ABC 7: “This is exactly what we expected and in fact it is probably better than expected.”
Of the more than 3,600 COVID-19 cases documented in Sonoma County during the same period, the 39 “breakthrough” infections represent about 1% of the total. And the vaccine trials of the Pfizer and Moderna vaccines found that they were both more than 90% effective in preventing infection, and even more effective in preventing serious diseases.
“No one in the study got a serious illness, was admitted to hospital or died, which is very important to know, even if they are not completely protected,” says Dr. Chin-Hong to ABC 7.
Stories of these ‘breakthrough’ infections are likely to make headlines, and will unfortunately fuel vaccine coverage among Fox News viewers and others.
But really, it should just be a reminder that wearing a mask is still essential until the virus levels in the Bay are brought closer to zero.
As the New York Times reported last month, very small “breakthrough” infections have been found in initial studies following fully vaccinated health workers – the first group of Americans to be fully vaccinated from January. In one study, four such infections were found among 8,121 employees who were fully vaccinated at the University of Texas Southwestern Medical Center in Dallas. In the other, seven out of 14,990 workers at UC San Diego Health and the David Geffen School of Medicine at the University of California, Los Angeles, became infected more than two weeks after receiving both doses of COVID vaccine. These numbers show a seemingly constant rate of 0.05% chance of infection after full vaccination in the first actual studies of the vaccines, after deployment.
In all 11 cases in the studies, infected people showed mild symptoms or no symptoms at all.
A CDC study that followed 3950 vaccinated participants in six states over a 13-week period beginning in December found similar results. It showed that the two mRNA vaccines from Pfizer and Moderna in the real world conditions with a high incidence of viruses were 90% effective in preventing infection two weeks after the second dose, and 80% effective two weeks after the first dose.
Despite the fact that these health workers were at work in the study during a widespread virus transmission, there was also no evidence that virus variants infected the vaccines better than the original strains. . And experts suggest that ‘breakthrough’ infections can mainly infect people with immune systems that are weakened by drugs or other conditions, meaning that the vaccines simply cause weaker immune protection in those patients.
As for the Sonoma County data, Dr. Michael Vollmer, a specialist in infectious diseases with Kaiser Permanente, told the Press Democrat that the numbers match what Kaiser saw throughout his Northern California network.
“This is real proof that the vaccines are incredibly effective in preventing disease and are life-saving,” says Vollmer. “The more people we can vaccinate, the less chance the virus can spread current variants or create new ones.”
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