Inactivated vaccines
Inactivated vaccines use the neutralized version of the germ that causes a disease.
Inactivated vaccines usually don’t provide immunity as strong as live vaccines. So you may need several doses over time (booster shots) to get ongoing immunity against diseases.
Inactivated vaccines are used to create protection against:
•                           Hepatitis A
•                           Flu (shot only)
•                           Polio (shot only)
•                           Rabies

Live-attenuated vaccines
Live vaccines use a weakened (or attenuated) form of the germ that causes disease.
Because these vaccines closely resemble the natural infection they help prevent, they create a strong, long-lasting immune response. Just 1 or 2 doses of most live vaccines can provide a lifetime of protection against the germ and the disease it causes.
But live vaccines also have some limitations. For example:
• Because they contain a small amount of the weakened live virus, some people should talk to their healthcare provider before receiving them, such as people with weakened immune systems, long-term health problems, or people who’ve had an organ transplant.
•                             They need to be kept cool, so they don’t travel well. That means they can’t be used in countries with limited access to refrigerators.
Live vaccines are used to protect against:
•                             Measles, mumps, rubella (MMR combined vaccine)
•                             Rotavirus
•                             Smallpox
•                             Chickenpox
•                             Yellow fever

Messenger RNA vaccines—also called mRNA vaccines
Researchers have been studying and working with mRNA vaccines for decades and this technology was used to make some of the COVID-19 vaccines. mRNA vaccines make proteins in order to trigger an immune response. mRNA vaccines have several benefits compared to other types of vaccines, including shorter manufacturing times and, because they do not contain a live virus, no risk of causing disease in the person getting vaccinated.
mRNA vaccines are used to protect against:
• COVID-19

Subunit, recombinant, polysaccharide, and conjugate vaccines

Toxoid vaccines
Toxoid vaccines use a toxin (harmful product) made by the germ that causes a disease. They create immunity to the parts of the germ that cause disease instead of the germ itself. That means the immune response is targeted to the toxin instead of the whole germ.
Like some other types of vaccines, you may need booster shots to get ongoing protection against diseases.
Toxoid vaccines are used to protect against:
•                                  Diphtheria
•                                  Tetanus

Viral vector vaccines
For decades, scientists studied viral vector vaccines. Some vaccines recently used for Ebola outbreaks have used viral vector technology, and several studies have focused on viral vector vaccines against other infectious diseases such as Zika, flu, and HIV. Scientists used this technology to make COVID-19 vaccines as well.
Viral vector vaccines use a modified version of a different virus as a vector to deliver protection. Several different viruses have been used as vectors, including influenza, vesicular stomatitis virus (VSV), measles virus, and adenovirus, which causes the common cold. Adenovirus is one of the viral vectors used in some COVID-19 vaccines being studied in clinical trials. Viral vector vaccines are used to protect against:
•                                    COVID-19