Posted by on November 30, 2015 - 4:12pm

Biological differences between the sexes could be a significant predictor of responses to vaccines, according to researchers at the Johns Hopkins Bloomberg School of Public Health. They examined published data from numerous adult and child vaccine trials and found that sex is a fundamental, but often overlooked predictor of vaccine response that could help predict the efficacy of combating infectious disease.

Sex can affect the frequency and severity of adverse effects of vaccination, including fever, pain and inflammation,” said Sabra Klein, PhD, lead author of the review and an assistant professor at the Bloomberg School’s W. Harry Feinstone Department of Molecular Microbiology and Immunology. “This is likely due to the fact that women typically mount stronger immune responses to vaccinations compared to men. In some cases, women need substantially less of a vaccine to mount the same response as men. Pregnancy is also a factor that can alter immune responses to vaccines.”

Researchers conducted a review of existing literature on several vaccines including yellow fever, influenza, measles, mumps and rubella, hepatitis and herpes simplex to obtain evidence of the difference in responses between women and men. They also examined the effect hormonal changes that occur during pregnancy have on vaccine efficacy. Researchers found that despite data supporting a role for sex in the response to vaccines, most studies did not document sex-specific effects in vaccine efficacy or induced immune responses.

“Understanding the biological differences between men and women to vaccines could have led to better distribution of the H1N1 vaccine during the early months. Our review of the literature found that healthy women often generated a more robust protective immune response to vaccination when compared to men,” said Andrew Pekosz, PhD, associate professor at the Bloomberg School’s W. Harry Feinstone Department of Molecular Microbiology and Immunology. “An understanding and appreciation of the effect of sex and pregnancy on immune responses might change the strategies used by public health officials to start efficient vaccination programs, optimizing the timing and dose of vaccines so that the maximum number of people are immunized.” added Klein.

“The Xs and Y of Immune Responses to Viral Vaccines” was written by Sabra L. Klein, Anne Jedlicka and Andrew Pekosz.

Source:   Johns Hopkins Newscenter

Posted by on December 2, 2013 - 3:02pm

Polio, or poliomyelitis, has been nearly eradicated by the polio vaccines developed in the 1950’s, sparing countless children and adults from symptoms such as muscle weakness and acute flaccid paralysis. However, there are still three countries (Nigeria, Pakistan, and Afghanistan) that have never been polio-free. These countries are starting to serve as “exporters” of the polio virus, affecting China and Syria, countries that had previously been polio-free.

In 2011, a polio outbreak shocked the northwestern province of Xinjiang, China. There, 21 cases of acute flaccid paralysis were confirmed as wild-type poliomyelitis. China had been certified as polio-free since 2000 and was shocked at the outbreak in Xinjiang. A rigorous investigation and mass vaccination ensued to snuff out the source. A genetic analysis found that the virus had been imported from Pakistan, despite the fact that the originating subject (a 16-month-old girl) and family had no history of travel outside their province in China. China’s response was immediate and vigorous, administering 43 million doses of vaccine in late 2011, and there have been no new cases in China after October 9, 2011. While China was able to attack this outbreak quickly and successfully, Syria's recently confirmed cases of polio have been harder to contain as Syria's public health services are disrupted by civil war.

As humans are the only host for the polio virus, it is theoretically possible to eradicate it. The only way to truly eradicate polio is to vaccinate 100% of people routinely in each country. Poliomyelitis is carried in the intestines and can make its way into the sewage and water systems, but if everyone is vaccinated, it has nowhere to go—outbreaks cannot happen if everyone is immune. The recent outbreaks in China and Syria have been linked to suboptimal immunization rates, therefore leading to susceptible people in these populations.

Nigeria, Pakistan, and Afghanistan remain the three countries that have never been polio-free. Collectively, Nigeria, Pakistan, and Afghanistan have reported 119 cases of polio so far this year, showing a decrease from these nations that reported 182 cases in 2012. Preventing potential outbreaks in these countries will require vaccinating or re-vaccinating millions of people—which is challenging in countries facing civil turmoil. William Schaffner, MD, Professor of Preventative Medicine at Vanderbilt Medical Center urges continued awareness of the importance of vaccination. These outbreaks in China and Syria confirm that global transmission of poliomyelitis can only be prevented if 100% of citizens are vaccinated in a routine and systemized way.

Source: MedPage Today

Posted by on August 30, 2012 - 2:05pm

The Centers for Disease Control and Prevention recommends pre-teens ages 11 to 12 to get the following vaccines: one dose of tetanus, diphtheria and pertussis vaccine, two doses of meningococcal conjugate vaccine, three doses of human papillomavirus vaccine and a yearly influenza vaccine.  With the school year approaching, this may be the ideal time to go as many teens will require physicals.

Pre-teens may also need to catch up on missed vaccines or vaccines that require multiple dosages.  The Advisory Committee on Immunization Practices (ACIP) recommendation for preteens can be found  at

The HPV vaccine prevents many kinds of cancer.  HPV infection can result in cervical cancer for women, penile cancer in man, anal or throat cancers in both genders.  The vaccine Gardasil can also protect against genital warts caused by sexual or skin on skin contact.  The vaccine has proven safe and effective for both sexes from ages 9-26. The ACIP suggests that adolescents start these vaccinations (one of three) at age 11 or 12, but older adolescents who missed the vaccinations can still catch up as long as they begin as soon as possible.  However, females should not get the vaccines past age 26 and males should not get the vaccines past age 21.  It is recommended that males who have sex with other males receive the vaccines until age 26.

While eleven and twelve may seem young to receive this vaccine, it is required so that all three doses are complete before any sexual activity occurs.  More antibodies against HPV are produced when vaccinated at a younger age.

Anyone under the age of 18 who are registered in new group or individual private health plans are able to receive certain vaccinations without any cost-sharing requirements-when provided by an in-network provider.  These vaccinations include Tetanus, Diptheria, Pertussis, Haemophilus Influenza Type B, Hepatitis A, Hepatitis B, Human Papillomavirus, Inactivated Poliovirus, Measles, Mumps, Rubella, Meningococcal, Rotavirus, and Varicella.

For additional information see:


Office of Adolescent Health at the U.S. Department of Health and Human Services:

Centers for Disease Control and Prevention:

Advisory Committee on Immunization Practices: