Doses of an updated Covid-19 booster vaccine will be arriving at health care providers in Texas this week: The centers for disease control and prevention will provide about 900,000 doses to Texas, including more than 502,000 doses of the Pfizer vaccine and nearly 193,000 of the Moderna vaccine to health-care providers. And an additional 200,000-thousand doses will be available through retail pharmacies. The updated vaccines are designed to protect against the original strain of Covid-19 and the Omicron variant. Which is responsible for more than 99 percent of the covid cases in Texas over the past month.