Vaccines: Nursing pharmacology

Vaccines are biological products designed to protect humans from potentially serious infections caused by various kinds of pathogens.

Most vaccines are routinely administered to clients as part of a vaccination schedule; while other vaccines are only given to certain populations, such as chronically ill clients or those travelling to foreign countries.

Now, there are five main types of vaccines: live attenuated, inactivated, subunit, toxoid vaccines, and mRNA vaccines.

Live attenuated vaccines contain pathogens that have been weakened in the laboratory. As a result, these weakened pathogens are no longer able to cause infection, but are still able to trigger a protective immune response.

These vaccines are used to protect against influenza with the live attenuated influenza vaccine or LAIV for short; as well as measles, mumps, and rubella, called the MMR vaccine, and can also include varicella zoster, also known as the MMRV vaccine; other live attenuated viruses include vaccines for rotavirus, smallpox, and yellow fever.

On the other hand, inactivated vaccines use a pathogen that has been killed in the laboratory, so it is no longer able to replicate or cause infection, but is still able to trigger a protective immune response.

These include vaccines against Hepatitis A, or HAV vaccine, as well as against polio, called the Salk vaccine or inactivated polio vaccine or IPV, and against rabies, or the rabies vaccine.

Another important inactivated vaccine is again for influenza with the inactivated influenza vaccine or IIV for short.

Next, subunit, recombinant, and polysaccharide vaccines contain just the portion of the pathogen that stimulates the immune response, such as a viral protein, DNA, or sugar.

Some of these vaccines are combined with proteins to form conjugated vaccines, which elicit a much stronger and longer lasting immune response.

These vaccines are used to protect clients against Haemophilus influenzae type B, or HiB vaccine; Hepatitis B, or HBV vaccine; Human papillomavirus, or HPV vaccine; Streptococcus pneumoniae, with the pneumococcal conjugate vaccine or PCV13, and the pneumococcal polysaccharide vaccine or PPSV23; and Neisseria meningitidis with the meningococcal conjugate or MenACWY vaccine and the serogroup B meningococcal or MenB vaccine.

Another important vaccine is again for influenza, with the recombinant influenza vaccine or RIV for short; as well as the recombinant zoster vaccine, or RZV, to prevent the reactivation of varicella zoster and development of shingles; as well as the adenovirus vector SARS-CoV-vaccine to protect against COVID-19.

Then, toxoid vaccines contain inactivated toxins produced by pathogens, and are used to protect against tetanus and diphtheria. Sometimes, toxoid vaccines are combined with subunit vaccines to make a more immunogenic, or strong, vaccine.

This is the case of the DTaP and TDaP vaccines, which provide immunity against tetanus, diphtheria, and pertussis.

Finally, the most recent vaccine technology involves messenger RNA or mRNA vaccines, such as the Pfizer-BioNTech and the Moderna vaccines for SARS-CoV-2, the virus that causes COVID-19.

These vaccines contain a piece of genetic material or mRNA that codes for a harmless viral protein that’s unable to cause the disease, but it’s capable of triggering an immune response.

Now, vaccines can be administered in one of four ways: intramuscularly, intradermally, subcutaneously, or orally. Once administered, they stimulate the immune system’s response against a specific pathogen, just like it would occur after being exposed to an infectious disease.

As a result, the body is left with a supply of memory immune cells that will remember how to fight the pathogen in the future. One thing to keep in mind with inactivated, subunit, and toxoid vaccines is that the immune response generated is not as strong as that from natural infections or live attenuated vaccines, so clients may require “booster shots,” or additional vaccinations to help bring immunity levels back up over time.

Alright now, vaccines can sometimes cause mild side effects. For intramuscular, intradermal, or subcutaneous injections, there may be pain, swelling, or redness at the injection site.

In addition, vaccines can sometimes cause systemic flu-like symptoms, such as fever, malaise, headache, and anorexia, that usually last for a day or two.

In rare situations, however, there can be more serious reactions, including prolonged irritability, seizures, high fever, thrombocytopenia, and anaphylaxis, as well as rare autoimmune conditions like Guillain-Barré syndrome.

However, it’s important to mention that the low risk of developing these side effects from a vaccine outweigh the risks of getting the actual disease.

Still, there are some of the general contraindications and precautions for vaccines. First, clients who have a moderate or severe infection should wait until they recover before getting a vaccine.

Next, clients who have had a previous allergic reaction to a vaccine or any vaccine ingredient should avoid getting additional doses or boosters for that particular vaccine.

In addition, immunocompromised clients should not receive live attenuated vaccines because of the small risk of developing the infection even from the weakened pathogen.