East Bay Getting to Zero
SARS-CoV-2 scanning electron microscope image from NIAID

This page includes East Bay COVID viral levels, testing, vaccine, masking, prevention, treatment and other resources, updated monthly. Please click here to share feedback.

East Bay COVID updates

May-June 2023

These East Bay Covid updates will be on summer break from June to September 2023, then will be updated as needed with practice-changing updates rather than monthly. Thanks for visiting and reading!

There are still free COVID vaccines, tests and treatment in the East Bay, available to everyone in California regardless of immigration and insurance status and continuing after the end of the public health emergency.

Check the latest COVID wastewater levels: Bay Area & CA | US | wastewater guide & FAQs

Find the latest variants: Bay Area & CA (click on variants, region) | US | US wastewater | Global

Virus levels:

As of May 31, 2023:

To reduce the risk of respiratory illnesses, we recommend to:

  • Stay home and do a home test when sick.
  • Gather outdoors instead of indoors when possible.
  • When indoors in public and for gatherings: wear high-quality masks, open windows/doors and use air filters to maximize ventilation and/or test before gathering to prevent transmissions.

Click here to read our Wastewater FAQs and 💩 Feces Facts.


  • The XBB.1.16 and XBB.2.3 variants are increasing in proportion. As of May 31, 2023, Bay Area variant data shows that the new XBB.1.16 and XBB.2.3.variants are increasing in proportion (~12-14% each), while the XBB.1.5 variant (~59%) is decreasing after dominating from January to April. Boosters, paxlovid, remdesivir and molnupiravir treatment are still effective against severe disease from XBB1.5 and the newer variants. Read more about East Bay variants here.
  • Boosters increase protection against new variants: Recent data show us how immunity against Omicron wanes after 4-6 months and boosters are crucial to protect us against these new variants. Vaccine boosters are effective in reducing the risk of long Covid, severe disease and death, especially for people over 65 and those at higher risk. 
  • Stay healthy by getting the updated booster, wearing N95/KN95/KF94 masks and using rapid tests before gathering and when you have symptoms.


  • Second bivalent boosters are authorized for people ages 65+ four months after their first bivalent dose, and for people ages 5+ who are immunocompromised two months after their most recent bivalent dose.
  • Vaccination guidelines have been updated:
    • Everyone ages 6+ should get at least 1 bivalent vaccine dose (Pfizer or Moderna) to be considered up to date.
    • People ages 65+ may get a 2nd bivalent booster dose at least 4 months after the first one.
    • People who are moderately or severely immunocompromised may get additional bivalent booster doses at least 2 months after the previous one.
  • Get a free updated bivalent booster at local pharmacies, your medical provider, MyTurn.ca.gov, Vaccines.gov, or county sites.
    • When should I get the booster? If it’s been…
      • <2-3 months since infection/vaccination: If you are not immunocompromised, wait and plan to get the booster 3-6 months out.
      • 3-6 months since infection/vaccination: Get the booster soon. If you have an event or trip, get it 2-4 weeks before to optimize protection.
      • 6+ months since infection/vaccination: Get the booster ASAP.

Bivalent vaccine efficacy data:

  • Infection and hospitalization data finds that the bivalent booster protects against symptomatic and severe disease from the newest variants, including XBB.1.5.
    • Real-world data published in January show that the bivalent booster provided 48% additional protection against symptomatic XBB/1.5 infection compared to no bivalent booster.
    • CDC hospital data through March 2023 shows that people who got the bivalent booster had a 6x lower risk of dying from COVID-19 compared to those who didn’t get vaccinated and 1.4x lower risk of dying compared to vaccinated people who didn’t get the bivalent booster.
  • Immunity wanes over time, so boosters provide important protection. Updated COVID vaccine efficacy data from the April 2023 CDC ACIP meeting found:
    • Significant waning of vaccine efficacy by 4 months against hospitalization was seen in all age groups: 68% to 27% efficacy from 2 to 4 months in ages 18-64 (compared to unvaccinated) and 64% to 53% to 39% efficacy from 2 to 4 to 6 months after vaccination for people ages 65+. (Link-Gelles, slide 13)
    • While people who got the bivalent vaccine had lower rates of hospitalization, those who got the monovalent vaccine were further out from the last dose (median of almost a year), which likely also reflects waning over time. (Link-Gelles, slide 13 and CDC vaccine efficacy dashboard)
    • Immunocompromised people ages 18+ had lower overall vaccine efficacy: 30% to 43% to 31% efficacy at 2 to 4 to 6 months after vaccination. (Link-Gelles, slide 14). 
    • Waning was also seen in protection against ventilation or death from 76% to 54% from 6 months to 12 months after vaccination. (Link-Gelles, slide 20)
  • On April 10, DHHS and the White House announced the launch of “Project NextGen,” investing $5 billing in next generation Covid vaccinations and treatments, including nasal and pan-coronavirus vaccines.


  • Ventilation: The CDC released new indoor building ventilation standards in May 2023. They recommend aiming for at least 5 air exchanges per hour and using MERV-13 or better filters to reduce transmission of respiratory infections.
  • California isolation and quarantine guidelines were updated on March 13:
    • If you test positive for Covid, isolate for at least 5 days and wear a mask for 10 days.
      • You may leave isolation after 5 days if symptoms are gone or improving and have had no fevers for 24 hours without the use of fever-reducing medications.
      • Wear a mask around others for 10 full days after start of symptoms. If you had no symptoms, wear a mask for 10 full days after your positive test. You may remove your mask sooner than Day 10 if you have two negative tests in a row, at least one day apart.
      • Click here to download the Alameda County isolation PDF. Click here to read more isolation details from Alameda County.
    • If you were exposed and have no symptoms, test immediately and 3-5 days after your last exposure. Wear a mask for 10 days, even at home around others.
  • Masks: As of April 3 in California, masks are recommended but not required in indoor high-risk settings, including health care, long-term care, correctional facilities; homeless, emergency and warming and cooling centers. Individual facilities may still choose to make masks required.
    • Masks will remain recommended in public indoor and transit settings when community levels are high (or medium for vulnerable people).
    • Masks are also recommended when exposed to or infected with COVID-19.
    • If your goal is to prevent infection and long COVID for yourself and/or people you live with, we recommend following the wastewater levels above or the CDC transmission levels.


  • If you have health insurance in California, you can still get 8 free COVID home tests after the federal public health emergency ends on May 11. Insurance companies will still be required to cover 8 COVID home tests per insured person per month indefinitely. California insurance companies are also required to cover COVID-related costs through any licensed provider without copays, cost-sharing or prior authorizations until November 11, 2023 (a 6 month extension from the federal end thanks to CA Senate Bill 1473). After November 11, 2023, California insurance companies will still be required to cover in-network COVID-related costs. Click for more info about the end of the public health emergency for California residents.
    • For everyone: if you haven’t yet requested the 4 free COVID home tests from the federal government since December 19, you can still click here to request them or call 1-800-232-0233.
    • Contra Costa residents can get 4 additional free at-home COVID test kits per household by filling out this online form or by calling 833-829-2626.
    • For people with Medi-Cal, Medicare or private insurance: click here for instructions on how to get free tests through your insurance.
  • Are expired COVID home tests still useful? If you still get a clear “control” line, the test is likely to still be effective.
  • COVID test-and-treat: Paxlovid is still free and widely available! Community members at risk can get treatment at the same location and on the same day that you test positive and regardless of insurance or immigration status. Please encourage anyone who tests positive to contact their provider or a free test-and-treat center ASAP, as they may be able to get treatment.
  • Free COVID clinical consults for CA clinicians: California health care providers can now call (866) 268-4322 (COVID-CA) to receive free and confidential consultation on COVID-19 testing and treatment from the UCSF National Clinician Consultation Center.
  • What are current COVID treatment options?
    • Paxlovid, remdesivir and molnupiravir remain effective against the newer variants.
    • Viral rebound is common for both treated and untreated people with COVID-19. There is no evidence of resistance to Paxlovid. Treatment still helps reduce viral load and severity. Just make sure to re-isolate. 
    • Paxlovid expiration dates have been extended to 24 months by the FDA. Check updated expiration dates here.
  • How can we prevent long COVID? Aside from wearing masks and preventing infection, the latest data suggests that you can reduce the risk of long COVID if you get infected with:
    • Vaccination with at least 2 doses was associated with a 43% reduction of long COVID in a large systematic review of 41 studies.
    • Paxlovid treatment was found to reduce the risk of long COVID by 26% in a large VA study
    • Metformin (a safe and inexpensive medication usually used for diabetes) taken for 2 weeks during acute COVID infection was found to reduce healthcare utilization for severe COVID and the development of long COVID symptoms by 42% in a randomized control trial.
    • Ensitrelvir (a protease inhibitor like Paxlovid) taken once a day for 5 days was compared to placebo in a randomized control trial in people at lower risk (mostly ages 12-69, vaccinated, no medical risk factors for severe disease), and was found to reduce long Covid symptoms by 26-45%, shorten symptoms by a day and reduce time to first negative test. This study was also presented at CROI 2023. Ensitrelvir is already approved for COVID treatment in Japan.
    • A “healthy lifestyle” (BMI 18-25, never smoking, exercise, moderate alcohol intake, high quality diet, sleeping 7-9 hours per day) was found in the Nurses’ Health Study II cohort (all women, 97% white) to be associated with a lower risk of long COVID. Participants with 5-6 healthy lifestyle factors had 49% lower risk of long COVID.

The end of COVID emergencies:

Free Covid vaccines, testing and treatment will still be covered by insurance and available at pharmacies and community partners for uninsured people after the federal public health emergency ends on May 11 under CA law, the national PREP Act and new Bridge Access Program.   

  • In April 2023, the Department of Health and Human Services (DHHS) announced that some of the PREP Act protections for Covid vaccines and treatment distributed by the US through pharmacies and community partners will continue, including pharmacist-administered free vaccines and treatments and the national Covid test-to-treat program. The CA Covid test-to-treat program through Sesame care is also still available.
  •  DHHS also announced that they will partner with pharmacies to provide Covid vaccines and treatments such as Paxlovid free-of-charge to people without insurance coverage in the Bridge Access Program to be launched this fall.
  • People with insurance coverage in California will be protected from out-of-pocket charges for Covid testing, vaccines and treatment from any licensed provider until November 11, 2023. After that, California insurance companies will still be required to cover these costs in-network without out-of-pocket charges. Click for more info about the end of the public health emergency for California residents.

California’s COVID state of emergency ended on February 28, 2023. The end of the state emergency has led to the end of extra pandemic-era CalFresh benefits and the closure of some COVID testing and treatment sites. It may also impact hospitals’ ability to address staffing and space shortages as well as some COVID-related paid medical leave policies. Click for more info about the end of the public health emergency for California residents.

The end of the federal emergency on May 11, 2023 will result in:

  • The end of continuous Medi-Cal coverage. Medi-Cal recipients will have to manually renew and prove eligibility again.
  • The end of national requirements for insurance to cover COVID-related costs. A CA law (CA Senate Bill 1473) extends this requirement for 6 more months to November 11, 2023, so insurance coverage of home test kits and COVID-related health care costs in California will extend till then.
  • The end of requirements for insurance to cover all telehealth services; coverage will vary by state.

Click to read more about: the end of the California state emergency and the end of the federal emergency.

Latest COVID resources

Click here for more East Bay COVID guidance and resources on how to protect ourselves and our communities.