Match the following choices to questions 1–4:
a. innate resistance
b. naturally acquired active immunity
c. naturally acquired passive immunity
d. artificially acquired active immunity
e. artificially acquired passive immunity


A newborn’s immunity to yellow fever.

Verified step by step guidance

1. Identify the type of immunity described in the problem: A newborn's immunity to yellow fever.
2. Consider the source of the immunity: Is it from the mother's antibodies or from a vaccine?
3. Recall that passive immunity involves the transfer of antibodies from another source, rather than the individual's own immune response.
4. Determine if the immunity is naturally or artificially acquired: Natural acquisition occurs through natural processes like maternal transfer, while artificial acquisition involves medical intervention like vaccines.
5. Match the description to the correct type of immunity: In this case, the immunity is naturally acquired passive immunity, as it involves the transfer of antibodies from the mother to the newborn.

Key Concepts

Naturally Acquired Passive Immunity

Naturally acquired passive immunity occurs when antibodies are transferred from one individual to another through natural means, such as from mother to child during pregnancy or breastfeeding. This type of immunity provides immediate, but temporary, protection against pathogens, as the recipient's immune system does not produce these antibodies.

Innate Immunity

Innate immunity is the body's first line of defense against pathogens, consisting of physical barriers (like skin) and immune responses that are present from birth. It is non-specific, meaning it responds to all pathogens in the same way, and includes mechanisms such as inflammation and the action of phagocytes.

Active Immunity

Active immunity is the immunity that develops as a result of exposure to a pathogen or through vaccination, leading to the production of antibodies by the immune system. This type of immunity is long-lasting, as the body retains a memory of the pathogen, allowing for a quicker response upon future exposures.