Immunization during pregnancy is the administration of a

vaccine A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified.

to a

pregnant Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ca ...

individual. This may be done either to protect the individual from disease or to induce an

antibody An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of t ...

response, such that the antibodies cross the

placenta The placenta is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas and waste exchange between the physically separate mate ...

and provide

passive immunity Passive immunity is the transfer of active humoral immunity of ready-made antibodies. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta, and it can also be induced artificially, when ...

to the infant after birth. In many countries, including the US, Canada, UK, Australia and New Zealand, vaccination against

influenza Influenza, commonly known as "the flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptom ...

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease quick ...

and

whooping cough Whooping cough, also known as pertussis or the 100-day cough, is a highly contagious bacterial disease. Initial symptoms are usually similar to those of the common cold with a runny nose, fever, and mild cough, but these are followed by two or t ...

is routinely offered during pregnancy. Other vaccines may be offered during pregnancy where travel-related or occupational exposure to disease-causing organisms warrant this. However, certain vaccines are contra-indicated in pregnancy. These include vaccines that include live attenuated organisms, such as the MMR and BCG vaccines, since there is a potential risk that these could infect the fetus.

Tetanus and whooping cough vaccination in pregnancy

Newborns are at increased risk of infection, particularly before they receive their first infant vaccinations. For this reason, certain vaccinations are offered during pregnancy in order to induce an antibody response, resulting in the passage of

across the

and into the

fetus A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal dev ...

: this confers

on the newborn. As early as 1879, it was noted that infants born following smallpox vaccination in pregnancy were themselves protected against smallpox. However, the original smallpox vaccination was never widely used during pregnancy because, as a live vaccine, its use is contraindicated.

Tetanus Tetanus, also known as lockjaw, is a bacterial infection caused by ''Clostridium tetani'', and is characterized by muscle spasms. In the most common type, the spasms begin in the jaw and then progress to the rest of the body. Each spasm usually ...

is a bacterial infection caused by

Clostridium tetani ''Clostridium tetani'' is a common soil bacterium and the causative agent of tetanus. Vegetative cells of ''Clostridium tetani'' are usually rod-shaped and up to 2.5 μm long, but they become enlarged and tennis racket- or drumstick-shaped when ...

. Newborns can be infected via their unhealed umbilical stump, particularly when the umbilical cord is cut with a non-sterile instrument, and suffer a generalised infection. The tetanus toxoid vaccine was first licensed for use in 1938 and, during the 1960s, it was noted that tetanus vaccination in pregnancy could prevent neonatal tetanus. Subsequent trials showed that vaccination of pregnant women reduces infant deaths from tetanus by 94%. In 1988, the World Health Assembly passed a resolution to use maternal vaccination to eliminate neonatal tetanus by the year 2000. Although neonatal tetanus has not yet been eliminated, by 2017 there were an estimated 31,000 annual infant deaths from tetanus, down from 787,000 in 1987.

Whooping cough Whooping cough, also known as pertussis or the 100-day cough, is a highly contagious bacterial disease. Initial symptoms are usually similar to those of the common cold with a runny nose, fever, and mild cough, but these are followed by two or t ...

, or pertussis, is a contagious respiratory disease caused by the bacteria

Bordetella pertussis ''Bordetella pertussis'' is a Gram-negative, aerobic, pathogenic, encapsulated coccobacillus of the genus ''Bordetella'', and the causative agent of pertussis or whooping cough. Like '' B. bronchiseptica'', ''B. pertussis'' is motile and exp ...

. It is fatal in an estimated 0.5% of infants in the USA. The first vaccine against whooping cough was developed in the 1930s, and in the 1940s a study found that vaccination in pregnancy protected infants against developing whooping cough. The tetanus and whooping cough vaccinations are generally administered in combination during pregnancy, for example as the

DTaP The DPT vaccine or DTP vaccine is a class of combination vaccines against three infectious diseases in humans: diphtheria, pertussis (whooping cough), and tetanus. The vaccine components include diphtheria and tetanus toxoids and either k ...

vaccine (which also protects against diphtheria) or the 4-in-1 vaccine (which also protects against diphtheria and polio).

Influenza vaccination in pregnancy

Influenza Influenza, commonly known as "the flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptom ...

is a respiratory infection caused by

influenza virus ''Orthomyxoviridae'' (from Greek ὀρθός, ''orthós'' 'straight' + μύξα, ''mýxa'' 'mucus') is a family of negative-sense RNA viruses. It includes seven genera: ''Alphainfluenzavirus'', ''Betainfluenzavirus'', '' Gammainfluenzavirus'', ' ...

es. Pregnant women are disproportionately affected by influenza: in the 1918 pandemic, mortality rates as high as 27% were reported in this population and in the 1957 pandemic, nearly 20% of deaths in pregnancy were attributed to influenza. In the 2009 pandemic, even with medical advances, pregnant women accounted for a disproportionately high percentage of deaths. The influenza vaccine was first used in the US military from 1938, and then in the civilian population from the 1940s. Given the increased risk of influenza during pregnancy, public health bodies in the USA recommended that pregnant women should be prioritised for influenza vaccination from the 1960s, with the CDC endorsing the recommendation from 1997. However, it was not until 2005 that a randomised clinical trial formally demonstrated the efficacy of influenza vaccination in pregnancy. Following the 2009 pandemic, both Australia and the UK added influenza vaccination to the recommended schedule for pregnant women.

COVID-19 vaccination in pregnancy

is a respiratory infection caused by the SARS-CoV2 virus. Before COVID-19 vaccines were available, pregnant women who caught the disease were at increased risk of needing intensive care, invasive ventilation or ECMO, but not at increased risk of death. Infection significantly increased the risk of preterm birth, stillbirth and pre-eclampsia. mRNA COVID-19 vaccines were first rolled out in December 2020. At this time, in recognition of the risks posed by COVID-19 disease in pregnancy, the US and Israel offered the vaccines to all pregnant women shortly afterwards, and the first safety and effectiveness data therefore came from these vaccines and these nations. By March 2022, formal studies on the safety of COVID-19 vaccination in pregnancy including more than 185,000 individuals had found no increased risk of any obstetric complications following COVID-19 vaccination and in April 2022, a systematic review and meta-analysis of the data showed that, during the pandemic, COVID-19 vaccination reduced the risk of stillbirth by approximately 15%. At this time, 110 countries recommended COVID-19 vaccination in pregnancy, with a further 72 offering (but not recommending) vaccination.

Rubella vaccination to prevent fetal disease

Rubella Rubella, also known as German measles or three-day measles, is an infection caused by the rubella virus. This disease is often mild, with half of people not realizing that they are infected. A rash may start around two weeks after exposure and ...

, or German measles, is an infection caused by the rubella virus. In childhood, it usually causes a mild disease but infection in pregnancy can result in fetal infection, or

congenital rubella syndrome Congenital rubella syndrome (CRS) can occur in a developing fetus of a pregnant woman who has contracted rubella, usually in the first trimester. If infection occurs 0–28 days before conception, the infant has a 43% risk of being affected. If t ...

, which causes neonatal deaths, deafness, blindness and intellectual disabilities. The first rubella vaccine was licensed for use in 1969, with its development largely spurred by the heavy burden of congenital rubella experienced in the 1960s. Because the rubella vaccine is a live attenuated vaccine, there is a theoretical risk that it could cause fetal infection, although this has never been seen to occur. Therefore, rubella vaccination is usually avoided during pregnancy. Rather, vaccination is offered to children to reduce the prevalence of rubella virus in circulation and/or to adolescent girls, to boost their immunity before they are likely to conceive.

References

{{DEFAULTSORT:Immunization During Pregnancy Vaccination Infectious diseases Obstetrics Health issues in pregnancy COVID-19