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

Trustworthy information about COVID-19

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 when:

  • unvaccinated (or have not received a booster if it has been more than 5 months after initial vaccination;
  • exposed many times, more frequently and for more extended periods of time (having a higher "viral load");
  • immunities are low in general (have a chronic disease or cancer, but also people who smoke); 
  • in physical contact or close 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 resources needed 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:

  • older (particularly people 85 or older, followed by those 65 -84);
  • not yet vaccinated;
  • people with vulnerable medical conditions;
  • people with poor access to healthcare; 
  • 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.

Besides having a higher risk of catching COVID, people with chronic illness or vulnerable medical conditions are more likely to worsen or die from those medical conditions if they are infected with COVID (so-called "excess deaths").

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 CDC guidance below for protections (including disease-specific action plans) for these conditions.

COVID-19 in children may show different symptoms than adults, or 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.

Navigating kid-related activities by COVID-19 risk tolerance level

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:

  • 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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