Two-thirds of Californians are unaffected by COVID — are you seeing the end? – Marine Independent Journal

New data show that more than two-thirds of Californians have antibodies to the COVID-19 virus and are approaching the so-called “herd immunity” at the end of the pandemic.

In just one month, the proportion of protected Golden State inhabitants jumped from 47% to 67%, and may now be even higher, according to an analysis released last week by state epidemiologist Dr. Erica Pan. There is sex. Some of that protection comes from past infections, but the recent surge from March to April suggests that the state’s expanded immunization campaign is the most credible.

“It’s a remarkable improvement,” said Dr. Stephen Goodman, a professor of epidemiology and population health at Stanford University. “It’s still less than we want, but with such a big jump next month, we’re in great shape.”

However, there remains variability across states, 48% in the Far North, 68.7% in the Bay Area, and 76% along the southern border, leaving geographical differences in the risks of those who have not yet been vaccinated. I am.

According to Dr. George Rutherford, an epidemiologist at the University of California, San Francisco, parts of the state are now moving towards herd immunity with very low levels of viral infection in some communities.

“At some point, perhaps in the next few months, we’ll reach what looks like herd immunity,” he said, making the Bay Area one of the first areas to reach that coveted goal. He added that there is a possibility.

There is an optimistic view nationwide. According to a recent report by the US Centers for Disease Control and Prevention, infections could drop to low levels this summer if vaccination rates remain high and vaccines are effective against mutants.

Recently, there are clues as to whether the United States will achieve full herd immunity. This is when the virus stops spreading because so many people have antibodies. But infectious disease experts say it’s not an all-or-nothing goal. When the population gains immunity, infection slows down. As a result, geographical areas are safe, if not states or countries as a whole.

Infectious disease experts say the virus is unlikely to be eradicated. Instead, they predict that it will cause sporadic outbreaks, but then die.

What percentage of the population needs to have COVID-19 antibodies to provide this widespread protection to the entire community?

Dr. Art Raingold, a professor of epidemiology at the University of California, Berkeley, is still unknown. Estimates range from 70% to 90%, depending on the model used... Thresholds can change and are determined by many factors other than vaccination, such as population density and viral infections.

“There is no magic cutoff,” he said. “It’s really a continuum,” “not the concept of” yes “or” no, “and the vulnerability decreases as antibody levels increase.

There is another unknown: the second arm of the immune system, which causes so-called “cell-mediated immunity,” may also protect us, Reingold added. Not measured by these antibody tests.

In the Bay Area, a test conducted in April showed evidence of antibodies produced in response to a vaccine or infection in 68.7% of the population. According to state data, this compares to 40.5% of the tests conducted in March.

The state’s highest level of immunity (76%) was along the southern border with Mexico, which suffered from many infectious diseases early in the pandemic. The lowest 48.8% were in the northern part of the state, were less susceptible to the virus and were more resistant to vaccination.

The state used tests to measure so-called “neutralizing antibodies” for the study. It is a protein that prevents infection by binding to parts of the virus that latch and invade human cells. Antibodies are produced after infection and after vaccination.

There are major statistical warnings. Due to the state sample size, these are ambiguous estimates. The true number can be higher or lower. For example, antibody levels in the bay area can range from 60% to 78%. Because of this range, state-wide variability may be less than it looks.

In addition, people sampled in an area may not represent the entire area. For example, they may have been younger or older, and they may not have been more pleased with the vaccination. Antibody test data reported to the California Public Health Service was collected from individuals in blood banks and clinics, among other sites.

According to epidemiologist George Lemp, a better approach is to perform random tests in critical locations such as post offices and grocery stores.

There can also be pockets of infection within a single area. The number of regions is just an average.

“You can’t just look at the numbers in the big regions to find out where our risks are,” Goodman said. In some Bay Area communities, 90% of eligible people could be vaccinated, he said. Elsewhere, it may be only 40%.

Experts agreed that this would be a challenge for state health authorities considering whether to lift the mask obligation. Anything that is appropriate for one locale can harm another.

“We are a big state,” Reingold said. “There may be herd immunity in a small town in Northern California and no herd immunity in Los Angeles … There will be no state-wide herd immunity in the near future.”