Fear of interactions between the Covid vaccine and other vaccines, as well as overdose due to conflicting reports on efficacy and side effects, have contributed to a further drop in vaccinations. But on the subject in general there are many rumors and unfounded news. To clear the field of doubts we talked about it with the teacher Maria Chironnaprofessor of hygiene at the University of Bari.
- Vaccines are only useful before an infection: false
Although vaccination is by definition a preventive intervention, there are situations in which it can be done when the infection is ongoing and is called “post-exposure prophylaxis”. An example is rabies vaccination given to individuals who have been bitten or who have come into contact with a rabies animal. Measles and chickenpox vaccinations may also be effective after exposure to infection: measles vaccine, if given within 72 hours of exposure, can prevent disease or reduce the severity of symptoms. With regard to chickenpox, the studies conducted so far indicate that vaccination up to 5 days after exposure to the virus is useful for prevent disease or reduce its severity.
- All vaccines are used to produce specific antibodies: true
Vaccines are biological preparations that contain microorganisms (or only some of their components) deprived of pathogenic power but with high antigenic power, and which once administered are able to induce a state of active immunity in the subject. without determining the disease. The mechanism is therefore to produce specific antibodies and cells of the immune system trained to destroy pathogens.
- Vaccines with live microorganisms are no longer used: false
Anti-measles, anti-mumps, anti-chickenpox, anti-rotavirus are based on live microorganisms deprived of pathogenic power. Then there are vaccines with killed microorganisms (anti-poliomyelitis, anti-influenza, anti-hepatitis A) to which are added those prepared with innovative technologies such as recombinant DNA (anti-HPV) or mRNA (anti-Covid19).
- Vaccine boosters are always needed: false
In some cases, such as theyellow anti-fever, one dose may be sufficient, in other cases more doses are needed to be administered according to a well-defined timing to ensure maximum protection over time. For some vaccines, however, they are provided “Boosters” or booster dosesthis applies for example to antidiphtheria, anti-tetanus, anti-whooping cough …
- The Novavax covid vaccine uses a new technology: fake
This anti-covid vaccine does not use mRNA technology (like Pfizer and Moderna) but recombinant DNA technology, which has already been used for decades for the preparation of other vaccines such as that against human papillomavirus (HPV) or anti-hepatitis B. This vaccine also contains an adjuvant (Matrix-M ) which serves a enhance the immune response.
- Active attenuated virus vaccines provide longer-term protection: trueThe protection induced by these vaccines is in general more prolonged over time. They can give more frequent adverse events but these, in general, are not serious and occur with significantly less frequency than the damage that can instead derive from the disease. So getting vaccinated is always advantageous.
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