The Flu, Vaccines, Pregnancy and You

It seems we have always talked of ‘the flu’ and ‘the flu shot’, but over the last several years we have been inundated with stories of new forms of the influenza virus that sound as if they would have greater importance to veterinarians than to medical physicians. First we were warned of avian or bird flu and more recently, of course, swine flu or H1N1. Not surprisingly, both of these viral forms have many looking at our avian and mammalian friends with a more suspicious eye. But these critters are actually reservoirs for these viruses. What is influenza? How is it spread? How is infection treated and who should be vaccinated? And what if I am pregnant? All of these are important questions.

The influenza virus causes an acute upper respiratory illness accompanied by fever. This highly contagious infection is spread by respiratory droplets and usually occurs as an epidemic, or in the case of the ‘swine’ flu, a pandemic, during the winter months. ‘The flu’ or an influenza viral infection is characterized by the abrupt onset of fever, chills, headache, achy, sore muscles and general malaise accompanied by respiratory symptoms such as a dry cough and runny nose. Complications of influenza infection include pneumonia, which occurs in up to 12 percent of influenza-infected pregnant women.

Treatment of influenza infection includes supportive care with rest and hydration and, in non-pregnant women, anti-viral medications. Because the effect of antiviral therapy on the fetus is not known, its use in pregnancy is limited to cases of severe infection where the benefits outweigh the risks.

Who should receive the seasonal influenza vaccine? According to the Centers for Disease Control it is recommended that the following individuals receive the seasonal influenza vaccine:

1) Children aged 6 months to age 19 years
2) Pregnant women
3) Persons aged 50 years and older
4) People of any age with certain chronic medical conditions
5) People who live in nursing homes or other long-term care facilities
6) Those persons who live with or care for individuals at high risk for complications of flu including healthcare workers and household contacts of those at high risk for complications from the flu and household contacts of those less than 6 months of age.

A question I receive almost daily is whether or not one should receive the influenza vaccine if they are pregnant. Not only may pregnant individuals receive the flu vaccine when they are pregnant, but it is recommended. Both the American College of Obstetrics and Gynecology and The Centers for Disease Control recommend vaccination of all pregnant women during the influenza season. Vaccination can be performed at any time and at any gestational age using the intramuscular, inactivated vaccine and this vaccine is safe in breastfeeding women. The intranasal vaccine uses live virus and should not be used in pregnancy.

In terms of the H1N1 vaccine (swine-flu vaccine) due to be released in October, similar recommendations for who should receive the vaccine have been expressed by the CDC and the healthcare community including the vaccination of pregnant women. Much apprehension surrounds this recommendation because many feel this vaccine has been rushed to market and, because it is a new vaccine, there exists a fear that little is known about its safety profile.

In at-risk individuals, the benefits are thought to greatly outweigh the risks. In pregnant individuals specifically the likelihood of hospitalization from severe symptoms is four times greater than in the general population and six percent of confirmed deaths from H1N1 infection have occurred in pregnant women. It is important to remember that pregnant individuals are in an immunocompromised state and they, therefore, have greater difficulty fighting these infections.

As for concerns regarding the preparation of this new H1N1 vaccine, each year a new seasonal influenza vaccine is formulated with the intention of protecting people against the three strains that are predicted to be the greatest threat. Although the H1N1 virus poses unique health risks, the process through which the vaccine has been developed is largely the same as for the seasonal influenza vaccine.

There are currently studies on H1N1 vaccination in pregnancy ongoing at Baylor and the University of St. Louis. We hope to gain more detailed information about this vaccine in pregnancy through these studies. In the meantime, it is recommended that at-risk individuals, including those who are pregnant, receive the vaccine.

I hope you have found this brief summary to be both useful and informative and remember, if you have questions or concerns, there is no substitute for direct consultation with your healthcare provider.