Vaccination

Comparing COVID-19 vaccines: How are they different?

Even if you're still waiting for a vaccine, watching the first people get their COVID-19 vaccinations may have felt like a huge relief. As the weeks pass, countless reports are coming out about the effectiveness of new vaccines ...

Medical research

New coronavirus variant surging in California

(HealthDay)—A coronavirus variant first identified in California is more contagious than previous forms of the virus and is spreading across the state, two new studies show.

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Immunity (medical)

Immunity is a biological term that describes a state of having sufficient biological defenses to avoid infection, disease, or other unwanted biological invasion. Immunity involves both specific and non-specific components. The non-specific components act either as barriers or as eliminators of wide range of pathogens irrespective of antigenic specificity. Other components of the immune system adapt themselves to each new disease encountered and are able to generate pathogen-specific immunity.

Adaptive immunity is often sub-divided into two major types depending on how the immunity was introduced. Naturally acquired immunity occurs through contact with a disease causing agent, when the contact was not deliberate, whereas artificially acquired immunity develops only through deliberate actions such as vaccination. Both naturally and artificially acquired immunity can be further subdivided depending on whether immunity is induced in the host or passively transferred from a immune host. Passive immunity is acquired through transfer of antibodies or activated T-cells from an immune host, and is short lived, usually lasts only a few months, whereas active immunity is induced in the host itself by antigen, and lasts much longer, sometimes life-long. The diagram below summarizes these divisions of immunity.

This text uses material from Wikipedia, licensed under CC BY-SA