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Vaccines and boosters protect against more infectious subvariant


With cases rising in LA County and across the country associated with the highly infectious BA.2 subvariant and sub-lineages, getting vaccinated and boosted is an important strategy to prevent serious illness, especially as there are many upcoming opportunities for celebrations and observances this month.

For the week ending April 16, Omicron accounted for 100 percent of all positive cases that were sequenced, with the BA.2 lineage and sub-lineages accounting for 96 percent of these positive sequenced specimens in LA County. For the week ending April 30, the CDC estimates that BA.2 accounted for 62 percent of sequenced specimens and BA.2.12.1 accounted for 37 percent of positive sequenced samples in the U.S.

The CDC estimates that BA.2.12.1 may be 25 percent more transmissible than BA.2. In Los Angeles County, for the week ending April 16, 8 percent of positive sequenced specimens were identified as BA.2.12.1.

With these highly infectious subvariants and sub-lineages in circulation, cases are increasing in LA County. The average number of daily new cases reported over the last seven days increased to 2,532 compared to the 905 reported one month ago, an increase of 180 percent.

To date, the increases in case numbers have not translated to increases in severe illness, with hospitalizations and deaths remaining low and decreasing.

The lower numbers of hospitalizations and deaths reflect, in large part, the protection provided by the vaccines against the variants. For the week ending April 22, unvaccinated people were four times more likely to be hospitalized compared to residents who were fully vaccinated, but not boosted, and five times more likely to be hospitalized than those fully vaccinated and boosted.

“As always, we extend our deepest sympathies to everyone mourning the loss of a loved one from COVID,” said Dr. Barbara Ferrer, PhD, MPH, MEd, director of Public Health. “This month, there will be many opportunities for gatherings, including graduations, proms, and the upcoming Memorial Day holidays. For these occasions to not contribute to the increasing spread of Omicron variants, we encourage attendees to take sensible precautions that will protect you and those around you, including staying outside as much as possible and wearing a mask when indoors.”

A wide range of data and dashboards on COVID-19 from the Los Angeles County Department of Public Health are available at