Non-clinical sciences/Immunology · Vaccines

Inactivated / subunit / mRNA vaccines

What it means

Non-replicating → safe in immunosuppression/pregnancy; usually need boosters. Inactivated: polio (IPV), hepatitis A, rabies. Subunit/conjugate/toxoid: HPV, Hib, pneumococcal, meningococcal, hepatitis B, tetanus/diphtheria. mRNA: COVID-19.

Worked example

Pertussis, flu, COVID and RSV vaccines are offered in pregnancy precisely because they are not live.

In the exam

A pregnant woman is offered vaccination against whooping cough; this is safe because the vaccine contains no live organism.

What settles it

Inactivated/subunit/mRNA = safe when immunosuppressed/pregnant; live attenuated = contraindicated.

Classically confused with

Live attenuated vaccines

Source: Green Book (UKHSA)