What experts know about delta variants so far

Yet another coronavirus variant is scrambled by public health authorities around the world to control its spread.

Delta variant, First appearance in IndiaIs now spreading to more than 80 countries and is rapidly becoming the predominant version of the virus (SN: 5/9/21). In places like the United Kingdom, Delta has abolished the highly contagious alpha mutant, which was first identified in the country as the most common form of the virus.

The rapid spread of delta variants has forced health authorities to respond. For example, British authorities have postponed plans to reopen the country and set the date back to mid-July. In addition, Israeli health officials, who have nearly 60% of the population fully vaccinated, have reinstated the requirement for residents to wear masks indoors. This is a public health measure that was lifted 10 days ago.In the United States, places like Los Angeles County Even vaccinated people are advised to wear a mask indoors.. The World Health Organization also encourages everyone to continue to wear masks, while retaining the US Centers for Disease Control and Prevention guidelines that vaccinated people can go without masks in most situations. ..

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According to the latest research, Delta poses the greatest threat to unvaccinated people.In the United States, Delta is responsible for estimates 26.1% of cases Nationwide. Its prevalence doubles every two weeks.Narrowing down areas that include low-immunization states such as Missouri and Wyoming, Delta Already causing most of the infection In some places. On July 1, the Biden administration announced that a team of experts with test supplies and remedies would be sent to a hotspot in the United States to control the outbreak of the delta.

Concerns are growing globally.However 23.4% Many people around the world have been vaccinated with the COVID-19 vaccine at least once, and most of them live in wealthy countries. Less than 1 percent of people in low-income countries were shot.

So far, researchers know that the delta variant will be the central stage during the pandemic:

The delta spreads easily.

The coronavirus that causes COVID-19 has been successfully adapted to infections among humans and is still present, says Ravindra Gupta, a virologist at the Cambridge Therapeutic Immunology and Infectious Diseases Institute in the United Kingdom. ..

Alpha variant Somewhere about 50 percent contagious Delta seems to have outperformed its benchmark than previous versions of the virus (SN: 4/19/21).According to data from the British government’s public health organization, Public Health England, Delta Increased infectivity by 60% From Alpha.

“That’s pretty worrisome,” says Ravina Kullar, an epidemiologist at UCLA and a spokesman for the Infectious Diseases Society of America.

People who are unknowingly infected with the delta variant are more likely to infect someone else, perhaps 7-8, Kullar said. “If someone has a delta variant, you can see the outbreak happening fairly quickly,” but it’s not isolated from others.

Mutants can evade parts of the immune system.

It’s not just a concern that Delta is likely to spread to others. At Delta, “there are viruses that have all these transmission benefits that Alpha has done,” Gupta says. However, Delta is superior to Alpha because it can dodge parts of the immune system. “It explains, in our view, why it’s causing problems everywhere,” says Gupta.

For example, antibodies from both recovered and vaccinated people Weak ability to prevent Delta from infecting cells More than the original version of the virus from Alpha or Wuhan, China, Gupta and colleagues, we will report in a preliminary study posted on Research Square on June 22nd. And when the team analyzed a cluster of COVID-19 cases of healthcare workers vaccinated with AstraZeneca shots at an Indian hospital in April, researchers found that most were infected with Delta. did.

The same was true for the other two healthcare centers in Delhi. This suggests that Delta is more likely to infect some vaccinated people. Breakthrough infection, From variants like Alpha (SN: 5/4/21).

Overall, vaccines still seem to be doing their job.

Even in the threat of breakthrough infections, vaccination protects people from the worst COVID-19 so far. For example, one preliminary study found that the COVID-19 vaccine appeared to be less effective against deltas than some other variants. But two shots are better than one shot.A single dose of Pfizer or AstraZeneca vaccine 33% effective in preventing symptomatological diseases Researchers reported May 24 on medRxiv.org about a delta infection three weeks after firing. This is compared to 55% effectiveness against alpha.

However, the second dose of Pfizer jab increased its efficacy against delta from 93.4% against alpha to nearly 88% against delta. A second dose of AstraZeneca’s shot is 66% to about 60% effective against alpha.

Protection from Hospitalization is even better, Researchers report June 21 in a preliminary study separate from the UK Public Health Services. A single dose of Pfizer’s COVID-19 vaccine was 94% effective in keeping people away from the hospital after infection with Delta, and a single dose of AstraZeneca was 71% effective. With two doses, these numbers increased to 96% and 92%, respectively.

And so far, in highly vaccinated areas such as the United Kingdom and Israel, the increase in COVID-19 cases has not yet been associated with a significant surge in hospitalizations and deaths. However, hospitalizations and deaths tend to lag weeks behind the increase in the number of cases, so it is time to tell if these numbers will increase.

Many are waiting, says Kullar, as there isn’t much information about vaccine deltas like Johnson & Johnson’s COVID-19 shots yet. However, the important point is that the more people vaccinated, the less likely Delta will cause problems in the community.

However, vaccines do not protect everyone equally.

The good news is that vaccinated young and relatively healthy people will probably be okay. However, “we have been hospitalized and we see the deaths of vaccinated elderly people and people with underlying illnesses,” Gupta says. Not all individuals receive the same level of protection from vaccines. In addition, children under the age of 12 are not yet eligible for vaccination.

Kullar agrees that there are still many people with immunodeficiency, such as organ transplant recipients, those undergoing cancer treatment, or the elderly who may still be at risk. Many of these people were “vaccinated and did everything they could. Now they rely on others around them to protect them.”

Experts are waiting to see the next variant appear.

Most likely delta Will not be the last variant Pops up during a pandemic (SN: 5/26/20). Vaccines still protect people, but as the virus circulates among unvaccinated people, it is more likely that variants will emerge that can significantly reduce the effectiveness of the vaccine. I will.

Tedros Adhanom Gebreyes, director of the World Health Organization, said at a press conference on June 25 that mutants would continue to emerge as the coronavirus spread. “It’s the function of the virus and it evolves, but preventing infection can prevent the emergence of variants. It’s very easy. More transmissions, more varieties. Less transmission, fewer variants.”

It is important to weaken the spread to reduce the chances of mutating the virus, Kullar says. “Before we think [alpha] I was worried, now I have a delta variant to put [alpha] It’s embarrassing. What’s coming next? “

Gupta says it may already be time to plan the future of the vaccine as new mutants spread. In the future, mutants may emerge that can evade the immune system much more effectively than delta or other current forms of the virus that cause vaccine problems. “This is not the end of the road,” says Gupta.