Archive

Posts Tagged ‘flu vaccination in pregnancy’

Evaluating the Safety of Flu Vaccination in Pregnancy

September 18, 2017 2 comments

The decision to get a flu vaccination in pregnancy is one that should be based on a complete evaluation of the scientific evidence that is available.  Flu shots have been safely administered to millions of pregnant women over many years, so how should expectant parents respond to a recent study that implies a connection between multiple flu vaccinations and the incidence of miscarriage in early pregnancy?  

To properly evaluate the significance of the latest data, we must consider the findings of this one report alongside the abundance of other science-based information we have, such as: 

  1. Why the Advisory Committee on Immunization Practices (ACIP) currently recommends flu vaccination among pregnant women.
  2. Data from the numerous studies that support the safety of the ACIP’s current recommendation of flu vaccine for pregnant women.
  3. Details of the “case-control” study in question and an examination of the study methods, findings and limitations.

Why the ACIP recommends flu vaccination among pregnant women.  

Currently the CDC’s Advisory Committee on Immunization Practices (ACIP) recommends that pregnant women get a flu vaccine during any trimester of pregnancy to help protect them and their newborns from the dangers of influenza.  Due to changes in the immune system, heart and lungs during pregnancy, expectant women are more prone to severe illness from flu, which has been known to result in premature delivery, low birth weight babies, miscarriage, hospitalization or even death.

Flu vaccination in pregnancy doesn’t just help protect the expectant mother from influenza, it is also the most effective way to pass critical immunity on to the baby during pregnancy.  This passive immunity can then protect the infant child from the dangers of influenza in the time before they are old enough to receive their own flu vaccination at six months of age.

The ACIP recommendation for flu vaccination during pregnancy is supported by other organizations as well, to include The American College of Obstetricians and Gynecologists (ACOG) and the American College of Nurse-Midwives (ACNM).

The studies that support the safety of flu vaccination in pregnancy. 

The ACIP is a committee which consists of 15 voting members who have expertise in vaccinology, immunology, pediatrics, internal medicine, nursing, family medicine, virology, public health, infectious diseases, and preventive medicine.  The Committee meets in person three times a year and subcommittees meet regularly throughout the year via conference call to discuss vaccine research and scientific data related to vaccine effectiveness and safety.

The current ACIP recommendation for flu vaccination during pregnancy is based on a thorough review of the evidence compiled from numerous studies, which include the following:

    • A review of reports to the Vaccine Adverse Reporting System (VAERS), a national vaccine safety surveillance program run by CDC and the Food and Drug Administration (FDA), (Moro et al, 2011) which found no unusual or unexpected patterns of reporting for pregnancy complications or adverse fetal outcomes among pregnant women and flu shots.
    • A study using Vaccine Safety Datalink (VSD) data (Irving et al, 2013) which found no increased risk of miscarriage among pregnant women who received flu vaccines in the 2005-06 or 2006-07 flu seasons. (The VSD is a collaborative program that monitors the safety of vaccines and conducts studies about rare and serious adverse events following immunization.)
    • A large study using VSD data (Kharbanda et al, 2013) which found no increased risk for adverse obstetric events (like chorioamnionitis, pre-eclampsia, or gestational hypertension) for pregnant women who received the flu vaccine from 2002 to 2009 compared to pregnant woman who were not vaccinated.
    • A VSD study (Nordin et al, 2014) which compared pregnant women who received the flu shot with an equal number of pregnant women who did not receive the flu shot during the 2004-05 and 2008-09 flu seasons. The study found no differences between the two groups in the rates of premature delivery or small for gestational age infants.
    • A large August 2017 study using VSD data which found that the babies of women who received the flu shot during their first trimester had no increased risk of having children with major birth defects.

The examination of vaccine safety is an ongoing process.  Before being approved for administration, vaccines undergo rigorous testing by their manufacturers, the FDA, and the FDA’s Center for Biologics Evaluation and Research. Clinical trials are performed before the vaccine is made available to the public, to confirm the vaccine’s safety and efficacy. Even after the vaccine receives FDA-approval, post-licensure studies are conducted on an ongoing basis to continually monitor the vaccine’s safety and to detect and respond to any rare adverse events.

While the studies conducted to date have not signaled any safety concerns, the ACIP and the CDC are committed to the continuous evaluation of the safety of all vaccines, to include those recommended for pregnant women.

This has led to the “case-control” study of flu vaccination and possible miscarriage which was recently published in the journal Vaccine on September 12, 2017 and reported on by The Washington Post, the Associated Press, and various other media outlets.  The study showed that women in early pregnancy who received two consecutive annual vaccines during 2010-11 and 2011-12, both of which included a 2009 pandemic H1N1 (H1N1pdm09) component, had an increased risk of spontaneous abortion (miscarriage) in the 28 days after receiving the second vaccine.

Details of the recently published study of women who had miscarriage following flu vaccination. 

Read more…

What You Should Know to Prepare for Flu This Season

September 29, 2016 Leave a comment

Earlier today, Tom Frieden, M.D., M.P.H., director of the CDC, joined leading medical and public health experts at the National Foundation of Infectious Diseases (NFID) News Conference to discuss the upcoming 2016-2017 flu season and vaccination coverage results from last season.

While flu season doesn’t “officially” begin until October 1st, Dr. Frieden reminded the public that the flu is unpredictable and there is no way to know when the virus will be circulating in your community.  This is why experts recommend getting yourself and your family members vaccinated now.

During his opening remarks, Dr. Frieden explained that the CDC has already tested 5,000 viruses and has begun to identify cases of flu across the U.S.  While it appears that this year’s vaccine will be a good match to the strains that were circulating at the end of last year, he explained that there’s no way to predict what type of flu season we will have in 2016-2017.  The best that we can do is to be get vaccinated.  flu

Dr. Frieden conceded that flu vaccination is not perfect. While we all wish it were better, he urged everyone over 6 months of age to get vaccinated since a flu vaccine can reduce a person’s risk of flu by at least 50%.  Flu vaccination also substantially reduces the risk of hospitalizations and other complications, while also reducing the risk of death.  In a bad year, the flu kills up to 49,000 Americans, 100 of which are infants and children.  Sadly, about 90% of the children who have lost their lives to flu were unvaccinated.

The most promising statement Dr. Frieden made in his opening remarks helped illustrate the enormous impact flu vaccination can have on our health and our communities. 

“If we could increase influenza vaccination coverage by just 5%, we would prevent 800,000 illnesses and almost 10,000 hospitalizations.”

Childhood Flu Vaccination According to the Numbers

Over the years, we’ve been making progress in increasing flu vaccination rates, however there is still plenty of room for improvement.

For example, Patricia Whitley-Williams, M.D., NFID Vice President and Division Chief and Professor of Pediatrics at Rutgers Robert Wood Johnson Medical School, stated that ten years ago only about 10-20% of children ages 6-23 months of age were vaccinated against flu. In contrast, last year about 75% of kids in that same age group were vaccinated for flu, exceeding our national public health goal.

Unfortunately, the goal has yet to be met in other age groups. Dr. Whitley-Williams explained that as kids get older, flu vaccination rates tend to decline, with only 47% of children 13-17 years being vaccinated last year.  This has had a direct impact on the 20,000 kids under the age of 5 who are hospitalized with flu related complications in this country every year.  While roughly 46% of people over the age of 6 months old were vaccinated last season, there were still 30 million kids that didn’t get a flu vaccine.

Vaccinating Healthcare Workers 

fight-flu-banner_585x338We are making progress among healthcare workers as well. The data indicates that 9 out of 10 healthcare workers were vaccinated last year, and there was also a slight increase in coverage among healthcare personnel working in long-term care settings such as nursing homes.  Yet, flu vaccination rates among adults age 50 and above decreased by  3% last year.

Importance of Flu Vaccine for Aging Adults 

Wilbur H. Chen, M.D., Associate Professor, University of Maryland School of Medicine concluded the news conference by address the concerns of a growing adult population.  The number of people age 60 and older will soon outnumber children 5 and under, and the concern is that this older demographic is often the hardest hit by flu.

Approximately 70-90% of influenza deaths occur among people 65 and older, and 50-75% of flu related hospitalizations occur in this age bracket as well.  While people are living longer, they can’t avoid the fact that our immunological peak appears to occur somewhere around age 45.  As a person ages, their immune system begins to decline resulting in higher rates of infection, more severe infections, and a lesser immune response when vaccinated.  At an age when flu vaccination is vitally important, only 63% of adults over 65 were vaccinated for flu last season.  Flu vaccination is an effective way to reduce illness and hospitalizations among this age group, while also helping to prevent other health complications such as heart attack and stroke.

Since pneumococcal and flu often go together, Dr. Chen suggested that older adults consider getting a pneumococcal vaccine in addition to their annual flu vaccine, if they haven’t already done so.  There are two different pneumococcal vaccines that are recommended to the public; the first is for everyone 65 and over, while the other is for those under age 65 with certain health conditions. While pneumococcal sends half a million people to the hospital each year, 4 out of 10 Americans over 65 still haven’t received a pneumococcal vaccine.

Importance of Flu Vaccination in Pregnancy

pregnant-women-vaccinated-by-flu-shotExperts continue to emphasize the benefits of flu vaccination among pregnant women.  Expectant woman are six times more likely to die from flu when pregnant, and contracting the flu during pregnancy can result in dangerous complications, to include pre-term labor.  Studies have shown that vaccinating pregnant woman can help protect the mother and her pregnancy while also transferring passive immunity on to their babies which can help protect them against flu for several months after they are born, while they are too young to be vaccinated themselves.  While flu vaccination coverage for pregnant women remained similar to previous season at 49.9%, this statitic measn that nearly half of all pregnant women and their babies are not protected from flu.

No Nasal Spray Flu Vaccine This Year

One of the biggest changes in the flu vaccine recommendations for the 2016-2017 season involves the elimination of the use of the nasal spray flu vaccine this year.   Read more…