Vaccination in pregnancy: reduced risk of serious illness and death from COVID-19, protection of the infant up to 6 months after birth


(Sabina Vohra – Miller Doctor of Public Health student, University of Toronto)

It was clear from the early days of the pandemic that COVID-19 infection in pregnancy could be serious. Hundreds of studies from around the world have consistently shown that infection with COVID-19 during pregnancy is associated with an increased risk of intensive care unit (ICU) admission, invasive ventilation, preeclampsia, and complications compared to other COVID-19 patients. There is a very high risk of death.

Statistics show that there is a five-fold higher risk of ICU admission and a 22-fold higher risk of maternal death due to COVID-19 infection in pregnancy. There are also significant risks to the fetus, including preterm delivery, low birth weight, as well as serious consequences such as stillbirth and neonatal death.

Studies have shown, and it is not much surprising, that stillbirths and neonatal deaths occur mainly in people who were not vaccinated against SARS-CoV-2 at the time of infection. The same study also showed that 90 percent of those hospitalized in pregnancy and 98 percent of those hospitalized in critical care due to COVID-19 infection were also unvaccinated.

Safety of COVID-19 Vaccines in Pregnancy

As a science communicator and Doctor of Public Health student, a lot of my work has focused specifically on understanding vaccine hesitancy. Despite overwhelming data on the risks of COVID-19 infection in pregnancy, many are still reluctant to get vaccinated, citing safety concerns.

Vaccination is safe at any time in pregnancy

We now have extensive evidence showing that the COVID-19 vaccination is safe when given at any time in pregnancy. Globally, several meta-analyses have confirmed that there is no evidence of a higher risk of adverse outcomes in the pregnant woman or the infant. There was no association between miscarriage, preterm delivery, placental abruption, postpartum haemorrhage, maternal death, low birth weight or neonatal intensive care unit admission with the COVID-19 vaccine given in pregnancy.

Vaccination produced positive health outcomes

In fact, most of these studies found that vaccination produced positive health outcomes: those who were vaccinated had a lower risk of stillbirth, premature birth, and admission to the neonatal intensive care unit and Apgar scores. was more favorable.

studies on child safety

Protection of infants from transfer of antibodies across the placenta Several studies have documented the presence of SARS-CoV-2 antibodies in cord blood after maternal vaccination. Confirming that vaccination has an added benefit, SARS-CoV-2 IgG antibodies – which are the most common type of antibody found in the blood, and protect against infection – are transferred from mother to fetus across the placenta, especially When vaccination is done in the third trimester of pregnancy. However, until recently it was unknown whether vaccination in pregnancy generates functional antibodies that can be detected in the infant after birth and, if so, whether they protect the infant from COVID-19 infection or severe infection. provide any benefit in terms of protection from disease.

IgG antibodies remain in the baby for several months after birth

Recent studies have shown that these IgG antibodies transferred to the fetus can remain in the baby for several months after birth. One study showed that 57 percent of infants born to vaccinated mothers had detectable antibodies at six months.

Delta and omicron variants in infants

A study by the Centers for Disease Control and Prevention (CDC) published in the Morbidity and Mortality Weekly Report (MMWR) revealed that COVID-19 mRNA vaccination during pregnancy reduced the risk of infection in infants less than six months of age. Was 61 percent effective in preventing hospitalization due to Covid-19 infection. A recently published study from Ontario assessed the effectiveness against Delta and Omicron variants in infants less than six months of age of mothers who received mRNA COVID-19 vaccinations in pregnancy.

This was revealed in the study

The study found that babies of mothers who received both vaccines had an effectiveness against hospitalization due to COVID infection at 97 percent for the delta version and 53 percent for the Omicron. Vaccine effectiveness against infantile omicron infection was found to be highest in the first eight weeks of life, but then declined in a stepwise manner.

Risk to babies under six months

Infections related to COVID-19 in children are generally mild, with considerable variability and a small number of children developing moderate or severe disease. However, children under six months of age are at highest risk of serious outcomes associated with COVID-19 infection, including hospitalization and death.

Benefits of a COVID-19 Booster in Pregnancy

Recently the World Health Organization recommended a Covid-19 booster during pregnancy if the last dose was taken six months ago. It is quite clear that the risk of COVID-19 infection in pregnancy is significant to the pregnant woman and the fetus. Given the high efficacy of COVID-19 vaccination in preventing severe disease in the pregnant woman, as well as the significant benefits for the infant, there is a strong and evidence-based indication to recommend routine COVID-19 boosters in pregnancies. Especially if the last dose was taken more than six months ago. Recommending additional boosters will give families a better chance to protect themselves and their children in the fourth year of the pandemic. We have a solution that has the potential to make a meaningful impact on maternal and child health. So my question is, what are we waiting for?


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