What is delta plus and what makes it different from the delta version of COVID-19?
SAN DIEGO (KGTV)  As the delta variant spreads in California, scientists have discovered more than 200 cases of a new branch that could be even stronger: a subline nicknamed the delta plus. Delta plus has all the distinctive mutations of its parent variant plus a noticeable mutation in its spicy protein. In previous studies on other variants, this mutation helped boost the pathogen against protective antibodies. This special [mutation] changes its shape slightly to avoid our antibodies, said UC San Diego virologist Dr. Davey Smith. Someone is vaccinated, they make a human immune response and this virus is able to avoid it a little better than previous types. The mutation is in the 417th position in the genetic code of the virus, known in the scientific community as K417N. It first gained fame in the beta version from South Africa. RELATED: Fast-spreading delta variant, the dominant COVID-19 strain in California  Delta, the parent variant that appeared in India and is now circulating worldwide, is now somewhat more resistant to vaccine protection than previous types and about twice as transmissible, raising concerns that delta plus may be even more virulent . In India, where the delta variant is already responsible for 90 per cent of new infections, health officials have called for even stricter efforts, evidence and tracing two weeks ago in areas where delta plus has appeared. The Indian government said the delta plus test is more transmissible and more elusive for antibody treatments and classified it as a particular variant of concern. Delta plus is so new that there is not much data on it, but it has been found in at least 15 countries and 17 US states, according to the GISAID database. RELATED: San Diego County will not recommend indoor masks because of the COVID-19 delta variant  Despite concerns about its power, it is not nearly as prevalent as the standard delta shape. There are only about 500 cases listed worldwide distributed on GISAID since it first appeared on Mars. The same database shows more than 120,000 cases of the standard delta variant, according to outbreak.info. As of Wednesday, there were 258 delta plus sequences documented in the U.S., according to GISAID, of which 210 were in California. Currently, the World Health Organization and the Centers for Disease Control and Prevention do not distinguish between delta and delta plus cases. The scientific community follows two delta plus fragrances, AY.1 and AY.2, and both are included in the agencys overall ratings for the delta variant. However, the CDC said it continues to collect data to determine whether delta plus should be classified separately. Overall, studies show that vaccines in the US are still effective against the parent delta variant, but not at the same level of 95 percent efficacy seen during clinical trials. A British study in May found that two doses of the Pfizer vaccine were 88 percent effective against delta. A Scottish study in June found the vaccine was 79 per cent effective. A Canadian study put efficiency at 87 percent. A study released this week by Israel found that the Pfizer vaccine was only 64 percent effective against delta. Dr. Smith said variable numbers should be expected because the studies were done outside of a controlled clinical trial. They are made with different populations, with different times and different ways of collecting data, he said. These studies examined so-called progression infections, where a vaccinated person develops symptoms, to start a small sample size. The good news in all of these studies is that people do not continue to develop severe COVID-19 or need hospitalization, he said. Dr. Smith said the vaccines clearly work against delta and are likely to work against delta plus. Health officials in England said June 25 that very preliminary results from a small number of vaccine recipients are reassuring, however further testing is required.