All three types of HPV prevention vaccines are safe because they do not contain viral genetic material. The nonavalent vaccine is no exception: it contains no viral particles, either attenuated or killed, but is made up of a protein synthesized in the lab (VLP = Virus Like Protein) that is normally present on the “cap” of the virus. The host’s immune defense system recognizes and immunizes the body against the virus carrying this “cap,” producing specific antibodies against the specific virus type, neutralizing it’s action at all levels. In the HPV vaccine, there are also so-called “adjuvants,” which are intended to enhance the effect of the immune system response . This way, a very small amount of vaccine can be used to obtain a large immune defense response from the body, including the genital cells.
Therefore, if naturally exposed to the virus, the immune system of the vaccinated subject is not caught off guard, but is able to react immediately and quickly produce specific antibodies that neutralize the types of HPV viruses included in the administered vaccine. Vaccination is a forward-thinking choice.
The administration of the HPV vaccine may in rare cases cause fever, pain, swelling and redness at the injection site. Sometimes it may cause headaches and muscle aches. These are all transient, short-lived effects, and there is no need to worry.
In December 2015, the IPVS (the International Papillomavirus Society) published a statement on the safety of HPV vaccines, reaffirming its good safety profile based on international ratings and recommendations. In addition, the number of documents published on the safety of vaccines by the World Health Organization (WHO) and by the extremely strict Food and Drug Administration (FDA) is by now numerous.
