You are vaccinated. You have COVID. How sick will you feel? – Times-Herald

The unvaccinated pandemic is now threatening those vaccinated – but new evidence shows that these startling ‘breakthrough’ infections tend to be milder, shorter, and only occasionally spread to others.

The trend is driven by the emergence of the highly transmissible delta variant, combined with the maskless rallies that began after the state reopened on June 15, said Dr Ralph Gonzalez, chief innovation officer for UC San Francisco. Health. Until now, people who have been vaccinated have almost always been protected from earlier variants or the original strain of the virus.

About 90% of the 183 recent COVID-19 infections among UCSF staff, researchers and students are confirmed to have been caused by contact with children, partners or unvaccinated people in the community, and not other vaccinated people, said Gonzalez, who is studying each case at the medical center. UCSF detects infections, even if they are asymptomatic, because people are tested routinely.

Scientists are still trying to understand what are known as “breakthrough” infections, defined as a positive test result in a vaccinated person.

These cases remain remarkably rare. A new analysis of availability state-level breakthrough data by the Kaiser Family Foundation found that of COVID-19 cases in California, 1.4% are in people who have been vaccinated and 98.6% are in people who have not been vaccinated.

There is a major reason why people vaccinated are unlikely to be major contributors to the pandemic: They are much less likely to be infected in the first place.

In some revolutionary cases, people may only carry traces of the virus, because their immune system has already detected and controlled it. In other cases, the virus may be abundant enough to spread to others, but it is controlled more quickly than in an unvaccinated person.

While the Centers for Disease Control and Prevention cited a recent group of revolutionary cases In Provincetown, MA, as evidence that vaccinated people easily transmit the virus, there has been only one incident at UCSF where a vaccinated person passed the virus to another person at work, he said. he declares.

One obvious difference is the masking. Especially in settings where people wear masks, like UCSF, “vaccine-to-vaccine transmission is very rare,” Gonzalez said.

And a new study by revolutionary cases in Singapore Also explains why vaccinated and unvaccinated people do not transmit at the same rate: Even though both groups had the same level of virus, vaccinated patients seemed to clear the virus from their bodies at a faster rate. This probably reduces the risk of transmission because that person is contagious for a shorter period of time.

“Based on our data, it seems likely that vaccination will reduce secondary transmission, although this needs to be further investigated in larger community-based surveillance studies,” reported Po Ying Chia of the Singapore National Center for Infectious Diseases. .

The case of vaccines stay extremely strong, say the experts. The vaccines are a little less effective during this current outbreak – by several estimates, they prevent about 80% of delta infection, compared to 95% with the alpha variant. But they are almost completely effective, at 95%, in the fight against serious diseases.

The problem isn’t that delta is dodging our vaccines. Instead, our bodies are just a little slow to respond to the delta assault.

“The immune system takes a little while to kick in,” said William Hanage, an epidemiologist at Harvard TH Chan School of Public Health.

Because the virus can multiply so quickly, he said, “it manages to copy itself before the immune system wakes up and hits it.”

According to a report released last week, of 10,262 breakthrough infections in the United States reported by the CDC in May, the majority were mild. About 27% were asymptomatic, 10% required hospitalization, and 2% died.

Symptoms reported by people with breakthrough delta infections are different from those seen with diseases with the alpha variant, Gonzales said.

The disease tends to be an upper respiratory infection, he said, with symptoms in the head and sinuses. People may experience sore throats, headaches, and loss of smell and taste. But they rarely suffer from lower respiratory tract conditions, such as life-threatening lung inflammation. At UCSF, hospitalization was only necessary for one case of rupture, and it was over-cautious. This person received supplemental oxygen and was released within three days.

“People are sick. Some of them have fever, ”Gonzales said. “But they’re all better.”

“Breakthroughs are always unpleasant,” he said. But compared to COVID-19 in the unvaccinated, “it doesn’t last as long and it’s not as bad.”

The Singapore study also found that fully vaccinated patients had significantly lower odds of moderate or severe outcomes than unvaccinated patients. This finding corroborates research from the UK which found that vaccination remains protective against symptomatic and serious illnesses.

Delta is a formidable enemy, said Dr. Robert Wachter, chair of the UCSF Department of Medicine. It is much more contagious than the original strain: a person with the original strain of the virus has infected an average of 2.5 other people; with delta, between five to nine new infections can come from a single case. Delta’s period of infectivity appears to be longer, with high levels of viral shedding lasting 18 days, rather than 13 days. It seems to cause more serious illness; a recent Scottish study concluded that delta was twice as likely as alpha to result in hospitalization.

Because this variant is now the dominant strain of COVID-19 circulating in the United States, better surveillance of breakthrough cases is needed to monitor vaccine effectiveness – and inform discussions about booster vaccinations, experts said.