Vaccines are designed to protect individuals from infectious diseases by stimulating the immune system to recognize and defend against specific pathogens without causing the actual disease. The likelihood of getting the disease from a vaccine is extremely low or non-existent for most vaccines.
There are different types of vaccines, including:
Inactivated vaccines: These vaccines contain killed versions of the disease-causing virus or bacteria. Since the pathogens are no longer alive, they cannot cause the disease in the person receiving the vaccine. Examples include the inactivated polio vaccine (IPV) and the hepatitis A vaccine.
Attenuated vaccines: These vaccines contain weakened forms of the live virus or bacteria. Although they are alive, they have been modified to replicate less effectively in the body and cause only a mild or asymptomatic infection. The weakened pathogen still stimulates the immune system to provide protection against the actual disease. Examples include the measles, mumps, and rubella (MMR) vaccine and the oral polio vaccine (OPV).
Subunit, recombinant, or conjugate vaccines: These vaccines contain only specific pieces of the virus or bacteria, such as proteins or sugars. They do not contain the whole pathogen, so they cannot cause the disease. Examples include the hepatitis B vaccine and the human papillomavirus (HPV) vaccine.
mRNA vaccines: These vaccines, like some COVID-19 vaccines, use a small piece of genetic material (mRNA) to instruct cells to produce a harmless piece of the virus's spike protein. The immune system recognizes this protein and builds protection against it, but there is no live virus involved, so the disease cannot be contracted from the vaccine.
The vaccines are thoroughly tested in clinical trials to ensure their safety and efficacy before they are approved for use. The risk of developing the actual disease from a vaccine is very low compared to the risk of contracting the disease naturally. Vaccines have been instrumental in preventing countless illnesses and have contributed significantly to public health.
In some cases, after receiving a vaccine, individuals may experience mild side effects such as soreness at the injection site, mild fever, or fatigue. These are normal immune responses and not the disease itself. Severe reactions to vaccines are extremely rare.
It's important to consult with healthcare professionals and rely on credible sources of information to better understand specific vaccines and their safety profiles. Vaccination is a critical tool in preventing the spread of infectious diseases and protecting both individuals and communities.