Vaccines in pregnancy

If one were to ask educated pregnant women in the major cities about their immunisation status, their usual reply would be that they have been vaccinated in their childhood. Hardly anyone knows beyond the two shots of tetanus in pregnancy. But there are a number of vaccine preventable diseases that can harm the baby.

Apart from the lack of knowledge of these vaccines, women hesitate due to concerns regarding their safety in pregnancy or the belief that they won’t fall prey to such diseases. As far as safety is concerned, all vaccines are checked for purity, safety and potency in a number of trials before they are recommended . While there are few vaccines which are recommended for all pregnant mothers others are to be given in selected cases only where the benefits of vaccination far outweigh the risks of the disease to the baby. For women who feel they wont need it, its like saying you don’t need helmets and seat belts. Even though the diseases may not be very common the harm caused to the baby is so bad that no stone should be left unturned to prevent  them.

Below I have listed the diseases that can and should be prevented by immunization during pregnancy , in the Indian context.

Tetanus/ Diphtheria and Pertussis : Tdap vaccine

This vaccine prevents neonatal Tetanus, Diphtheria and Pertussis i.e german measles, all of which are dangerous for babies. It can be given anytime during pregnancy but is recommended between 27-36 weeks of pregnancy. American College of Obstetrics & Gynecologists recommend that it is to be given in every pregnancy irrespective of previous history of vaccination.

In case the mother didn’t receive vaccine during pregnancy, she should get it in immediately after delivery to prevent transmission from mother to newborn.

TETANUS TOXOID:

 This vaccine covers only neonatal tetanus among the above three diseases. It is given in all government dispensaries. By persistent universal  coverage of pregnant women and new born immunization, India has been able to eliminate the much dreaded maternal and neonatal tetanus. However continued immunization is essential to prevent any future outbreak as the tetanus bacteria is present everywhere like soil, rust etc. In pregnancy, it comprises of two shots one month apart .

 

INFLUENZA :  FLU VACCINE

Cough & cold can be caused by a number of bacteria and viruses; Flu virus accounting for a majority of the cases. Compared to the general public, pregnant mothers are not only more prone to it, but they also have  a more severe course with more complications, sometimes endangering life.

The predominant strains (types) of the Flu virus keep on changing over time. Scientists study and predict the predominant strain , which is then used for the vaccine preparation prior to the peak season. So this is a seasonal vaccine which may be different every year.

 India recently had an epidemic of the commonly called Swine flu (H1N1 strain), of which cases are still appearing. Studies in the last few years show that the peak of Swine flu around New Delhi is from Jul-Oct and during peak winters. So all women who are pregnant during these months should get this single shot of inactivated Flu vaccine. As the body requires 4 weeks to develop immunity after the vaccination, the ideal time for vaccination around Delhi would be Apr-Jun. The immunity lasts for a year.

 

HEPATITIS A: HEPATITIS A VACCINE

Jaundice in pregnancy is usually caused by Hepatitis A and E, both of which are transmitted by contaminated food and water. Hepatitis E is more dangerous in pregnancy but unfortunately there is no vaccine for it. Hepatitis A vaccine is available and it should be given in selected cases where the benefits outweigh the risks.

As recommended by the WHO the vaccine is recommended for residents and travelers going to areas with high number of Hepatitis cases. It is also recommended if other high risk conditions coexist like Hepatitis B or C, diagnosed with HIV, treated with clotting factor concentrates or a woman with history of drug abuse.

Risk of infection of both the strains of Hepatitis is highest for those who live in or visit rural areas, trek in hilly areas or frequently eat or drink in settings with poor sanitation. The risk exists even for travelers to urban areas, those who stay in luxury hotels, and even those who report that they have good hygiene and are careful about what they eat and drink.

Travelers can minimize their risk by avoiding potentially contaminated water or food, such as drinking beverages (with or without ice) of unknown purity, eating uncooked shellfish, and eating uncooked fruits or vegetables that are not peeled or prepared by the traveler personally. Since a simple, safe vaccine exists, experts recommend that travelers to areas with high prevalence of Hepatitis A be vaccinated.

The Hepatitis A vaccine is given as 2 shots, 6 months apart.

HEPATITIS B:  HEPATITIS B VACCINE

Hepatitis B is a virus, which after infecting an individual can remain inside the liver lifelong and can cause Liver cancer in some. It has been a part of Universal Immunisation schedule for children only since the last few years. So most women are non-immunized for this disease.

Pregnant women who are identified as being at risk for HBV infection during pregnancy should be vaccinated. Women at risk would be those who had more than one sex partner during the previous 6 months, who had been evaluated or treated for a sexually transmitted disease, recent or current injection drug use, or having had an HBsAg-positive sex partner. The vaccination comprises of three shots at 0,1 & 6 months.

MMR, Chickenpox, HPV, Japanese Encephalitis vaccines are not recommended in pregnancy.

So my advise for all pregnant mothers – Go and discuss with your doctor and get yourself properly vaccinated. A shot in time will give you a healthy baby. Of course the prevention of the most dreaded diseases of this season- Dengue and Chikungunya , still remain a challenge for our scientists. A dengue vaccine is being tried out  but it will be some time before we all get to benefit from it.

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