March 2011: Gender and VAERS data

Do vaccines affect males differently than females?

This month I will look at VAERS data to see if there are any gender-related trends. It is easy to search for this information: simply Graph Vaccines and Gender. The graph appears here (with some vaccines removed where the numbers are insignificant). For an explanation of the vaccine codes along the left side of the graph, click here or here.

For the most part, an equal number of males and females are filing VAERS reports against each vaccine. There is always some difference between males and females for any particular vaccine, but usually the difference is not significant.

However, some vaccines do have significant differences. Some of these differences can be easily explained:

  • Anthrax affects more males than females, but this is because the vaccine is primarily given to military personnel who are mostly male.
  • HPV affects more females than males, but this is because the vaccine is mostly targeted towards females (although males are starting to get it and file VAERS reports.)

But some vaccines have significant differences that defy explanation, and all of them show more females being affected than males:

  • Flu, vaccine codes: FLU, FLU(10-11) and FLU(H1N1)
  • Hepatitis B, vaccine code: HEP
  • Pneumonia, vaccine code: PPV
  • Tetanus and Diphtheria, vaccine codes: TD and TDAP
  • Shingles, vaccine code: VARZOS

It would be reasonable to ask whether the disproportionate number of Flu, Hepatitis B, Pneumonia, Tetanus/Diphtheria, and Shingles VAERS reports filed by females was associated with also receiving the HPV vaccine during the same office visit. To find out, the VAERS data was searched to count the number of reports that list both an HPV vaccine and one of these others that affect more females. The table below shows the number of females and males listed for each of these vaccines, along with the number of VAERS reports that show an HPV vaccine being given at the same time.


Vaccine Number of VAERS cases
Females Males With HPV
FLU 30,856 14,472 354
FLU(10-11) 5,196 2,383 99
FLU(H1N1) 3,972 7,070 51
HEP 28,663 18,195 240
PPV 15,949 7,634 46
TD 11,300 4,565 60
TDAP 9,057 4,166 1,717
VARZOS 5,366 1,828 10

As the table shows, there are very few VAERS cases where an HPV vaccine was given along with one of these others. Even TDAP, which has a large number of VAERS cases that include an HPV vaccine, does not show enough inclusions to explain the disproportionate female affect of the TDAP vaccine.

Some of the vaccines that affect more females than males have alternate versions which do not show a disproportionate affect for females:

  • Flu The nasal Flu vaccines (codes FLUN, FLUN(H1N1), and FLUN(10-11)) do not show a significant gender difference.
  • Hepatitis B The combination vaccines such as HEPAB (“Twinrix” which includes Hepatitis A), HBHEPB (“Comvax”, which includes Haemophilus B), and even DTPHEP (which includes Diphtheria, Tetanus, and Pertussis) do not show a significant gender difference.
  • Pneumonia There are two other Pneumonia vaccines (PNC and PNC13) which do not show a significant gender difference.

Does this mean that females would be less likely to experience an adverse event following Flu, Hepatitis B, or Pneumonia vaccinations if they chose these alternatives? Such a question is best left to you and your doctor to discuss and decide.

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