Vaccinations are everywhere in the news at the moment – Paediatrician Dr Enrico Maraschin looks at what you need to know about vaccinations and pregnancy in general.
Immunity and vaccinations are current topics due to the Covid-19 pandemic. Understanding exactly how immunity works is a complex scientific subject, but people do generally understand the role of vaccines in relation to preventable diseases in babies and children.
A very exciting field is that of maternal immunisation. This is the practice of vaccinating a pregnant woman to protect both her and her unborn child.
At the 2019 annual meeting of the European Society for Paediatric Infectious Diseases, Dr Flor M Munoz, one of the key speakers, stated: “I think it’s important for everyone, especially people like myself who’ve been working on maternal immunisation for about 20 years, to realise that this is a historic study.”
She was making reference to the research on a vaccine which will soon be available to pregnant women to protect their babies against the RSV virus. I will discuss this a little later.
Although research and work in the field of maternal immunisation is over 20 years old, it is not a subject that is commonly discussed with those planning to fall pregnant or those who are already pregnant. As a result, many people have reservations and questions.
What is important to understand is that a pregnant woman often has a greater chance of contracting an infectious disease, because pregnancy hormones affect the immune response, making her vulnerable to infection.
Newborn babies are also very vulnerable due to the fact that their immune systems are immature and require time plus vaccinations to be able to fight off disease. Maternal immunisation addresses the vulnerability of both mother and baby.
What vaccines should I have before falling pregnant and why?
Rubella (German Measles) – German Measles is an illness that, if contracted during pregnancy, can lead to a miscarriage or birth defects such as blindness or brain damage.
Varicella (Chicken pox) – If a mother develops chicken pox during her pregnancy she is at a high risk of developing pneumonia. Her foetus may develop eye, brain, limb and other complications, especially between weeks eight and 20. If a mother develops chicken pox just before her delivery or within 48 hours after giving birth, her baby may be born with a life-threatening infection known as neonatal varicella.
Hepatitis B – A woman with Hepatitis B can pass it on to her baby during birth. This will cause serious, ongoing health problems for a baby.
Rubella and Varicella vaccines are live vaccines. They should be given at least one month before a woman decides to fall pregnant and cannot be given during the pregnancy.
What vaccines should I have while pregnant and why?
Flu vaccine – Pregnant women are at increased risk of severe complications related to flu. These complications may result in premature labour and delivery. A flu vaccine may only be given to a baby from six months of age but if the mother has had the vaccine, the immunity will cross the placenta barrier and pass the immunity onto the baby. Without the immunity, babies who get flu in the first few months of life often suffer serious complications like pneumonia. The flu vaccine should be given to the mother during the flu season. It is important that an inactivated flu vaccine be administered.
Tdap vaccine – This vaccine protects against tetanus, diphtheria and whooping cough (pertussis). Fifty percent of babies who suffer from whooping cough end up in hospital. It is a life-threatening condition. Tetanus and diphtheria are not common illnesses these days, but if a mother should contract one of these, it would be serious.
It is recommended that a mother receives the Tdap between 27 to 36 weeks of pregnancy. There are two Tdap vaccines available in South Africa. These are currently only available in the private sector and do not form part of the government schedule. The baby itself cannot receive the whooping cough vaccine until he or she is six to eight weeks old. In this period the baby is very vulnerable to the disease unless the mother has passed her antibodies onto the baby during the pregnancy.
What is to come?
RSV (Respiratory Syncytial Virus) – This virus affects the small airways of the lungs, making it difficult for a sufferer to breathe. It is the major cause of the common cold, but may also cause bronchiolitis or pneumonia. Sneezing or coughing is the most likely way to spread the virus. It can affect all age groups but is particularly problematic in small babies. Those born prematurely have added risks. The virus causes at least 1.4 million hospitalisations in the first six months of life and over 120 000 deaths in children. The vaccine is in the final stages of development and offers the only real solution to this disease at present.
Group B Streptococcus – This is a bacterial infection and is the most common cause of bacterial infection in newborns. A mother may carry Group B strep in her gut and vagina. This does not always mean that the baby will be affected, however, a baby who is exposed to Group B strep during birth may develop meningitis, pneumonia or sepsis. The vaccine being developed will be administered to the mother to protect her from infection but to also protect her child in the first few months of life.
Covid-19 – None of the current vaccines have been tested on pregnant women yet. Researchers are always cautious about including this group in trials because of the risks to the foetus. America’s Centers for Disease Control (CDC) has stated that pregnant women should be offered the vaccine, but in Britain they have advised against the vaccine until more data is available. Pfizer has stated that no safety concerns were raised in the preliminary studies, which were conducted on animals. This is a very difficult situation as pregnant women who get Covid-19 are at a very high risk of losing the pregnancy or developing complications like pneumonia, resulting in premature births. At the same time we cannot risk a vaccine in this group without data giving us an indication of its safety.
Maternal immunisation is a field of medicine which offers new hope to babies in the first weeks of life, when they themselves cannot be vaccinated. Their mothers are also given the opportunity to protect their own health in this very precious stage of life.