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COVID-19 Information: Santa Clara County and Bay Area, California

Trustworthy information about COVID-19

Protecting Those At-Risk for Severe COVID-19

People who are at greater risk for severe COVID-19 illness would be wise to go slow even when local restrictions are released. Continuing to self-isolate, maintain distancing, and following all the other measures described on the  Slowing the Spread of the Coronavirus page even after they aren't required would be wise. Also wise would be to insist that people caring for at-risk people continue to follow those precautions, too.

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Risk Factors for COVID-19 Infection

SARS-CoV-2 is a coronavirus, as are viruses that cause the common cold - but is more easily transmitted than a cold. It is spread by infected people, who often don't know they are infected because they have no symptoms (asymptomatic), because their own symptoms have not yet developed, or because early symptoms mimic a cold, flu, allergy or asthma.  

Broadly speaking, our chances of catching this disease are greater if we:

  • are unvaccinated (or have not received a booster if it has been more than 5 months after initial vaccination;
  • are exposed many times, more frequently and for more extended periods of time (having a higher "viral load");
  • have lower immunity in general (have a chronic disease or cancer, but also people who smoke); 
  • are in close physical proximity to each other (in schools or childcare settings, many people in the household, nursing homes, care settings, shelters, or prisons); and/or
  • don't have the resources to slow the spread of disease (poor access to healthcare, lack clean water or secure housing).

Unfortunately, these factors also seem to raise the chances of having a more severe case of COVID-19.

Vulnerable Populations

Early in this pandemic, older adults were especially vulnerable to COVID-19. While older people also tend to have chronic health conditions, or to be living in care centers, the number of fatalities among healthy seniors is higher than can expected from those factors alone. As this virus moved through populations, cases in younger people increased. At the present time, those most at-risk for serious disease (hospitalization or death) are those who are not yet vaccinated, followed by people with vulnerable medical conditions, people with poor access to healthcare, and people working in risky jobs. Data from many different states in the U.S. show that Black and Latinx people are more likely to catch COVID-19 and to have more serious illness, perhaps because of disparities in healthcare. Native reservations in the U.S. have been among the hardest hit regions in the U.S., too.


Vulnerable jobs: Heathcare workers are one of the most at-risk professions for severe COVID-19 illness. By treating sick patients, they have much greater exposure to the novel coronavirus than most people (a much higher viral load).  Grocery store workers, cashiers, bus drivers and taxi drivers also have higher rates of infection than the general public, for similar reasons.

The CDC, state, and local health departments have directives on what employers and employees should do to avoid spreading the novel coronavirus.


People with disabilities (physical, cognitive, behavioral or developmental) that make their activities of daily living more difficult for them, or who are dependent on other people for help with their activities of daily living, are also more vulnerable. See the links below for protections (including disease-specific action plans) for these conditions.


Children catch COVID-19 too, although their signs of infection can be different from adult symptoms (and may not show any symptoms at all). Rarely some children sick with COVID-19 experience multisystem inflammatory syndrome (MIS-C), which can be quite serious - but is treatable.

 Vaccines and boosters (including the bivalent booster) have been approved for children as young as 6 months old and up.

Parents face difficult decisions on how to best protect their kids; information from these sources may help.


Not having a stable home makes it extremely difficult to take care of one's health, especially during this pandemic. While services for the homeless are greatly needed, they need extra precautions as well.

Health Conditions that Make People More Vulnerable

While there is still much to learn about COVID-19, as of this writing, there is general agreement that these underlying medical conditions are associated with more severe COVID-19 symptoms are:

  • COPD
  • serious heart conditions (chronic heart failures, past heart attacks or cardiomyopathies
  • chronic kidney  disease
  • type II diabetes
  • sickle cell anemia
  • obesity

People with these conditions may also be more at risk for severe COVID-19: (it's still unclear)

  • smoking, vaping, or other lung conditions (moderate to severe asthma, pulmonary fibrosis)
  • other vascular or blood conditions (chronic high blood pressure, thalassemia, cerebrovascular disease)
  • dementia
  • liver disease
  • type I diabetes
  • immunocompromised (by cancer or HIV)

See the links below for instructions (including disease-specific action plans) on how to protect yourself if you have any of these conditions.

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