Pregnancy covid boosters safe and effective

3 minute read

But only high-risk women should be prioritised over others this year, RANZCOG says.

Covid boosters are safe and effective in pregnant women, according to new research. But updated RANZOG advice says only high-risk women with co-morbidities that increase the risk of severe covid should be prioritised to receive a booster dose.

The college updated its advice following ATAGI’s announcement that a fifth shot is recommended for anyone who has not been infected with covid who had their last vaccine more than six months ago.

Pregnant women who were not fully vaccinated were still a priority group, according to RANZCOG.

Pregnant women with covid have a higher risk of severe illness compared to non-pregnant women with covid, increasing the risk of hospitalisation, admission to an intensive care unit and invasive ventilation, it said.

These women should be routinely offered the Pfizer vaccine (Comirnaty) or Moderna (Spikevax) at any stage of pregnancy.

However, pregnant women did not need to have a booster dose if they had no pre-existing health issues, it said.

“At this stage, pregnancy is not considered a specific indication for a booster dose in women aged 18 years and over who do not have medical comorbidities that increase their risk of severe covid-19, or disability with significant or complex health needs.”    

The advice came as a study of 8800 infants found mRNA vaccination during pregnancy protected infants against infection and hospital admission.

“Three vaccine doses improved protection against omicron infection and admission to hospital,” the Canadian authors wrote in the BMJ.

“Vaccination during the third trimester of pregnancy provided the greatest protection, and effectiveness was highest in infants between birth and eight weeks of age.”

They found that a first vaccine dose during pregnancy gave less protection than two or three doses.

A second dose during pregnancy was highly effective against delta and moderately effective against omicron infection and hospital admission for the infant during the first six months of life.

“A third vaccine dose bolstered protection against omicron. Effectiveness for two doses was highest with maternal vaccination in the third trimester, and effectiveness decreased in infants beyond eight weeks of age.”

RANZCOG urged pregnant women to get vaccinated if they hadn’t had a full course already.

“Women who are trying to become pregnant do not need to delay vaccination or avoid becoming pregnant after vaccination,” the college said in a statement.

There wasn’t any evidence of increased risk of miscarriage or teratogenic risk with mRNA or viral vector vaccines.

The college pointed to global evidence showing the Pfizer and Moderna vaccines were safe for pregnant women. 

“Novavax covid-19 vaccine can also be used in pregnancy. While there are no immunogenicity or safety data, there are no theoretical safety concerns relating to its use in pregnancy, since the Novavax covid-19 vaccine, like other covid-19 vaccines, is not a live vaccine.”

RANZCOG recommended that pregnant women have two doses of the Pfizer or Moderna vaccine, three to six weeks apart, and a third vaccination three months after the second.

BMJ 2023, online 12 January

End of content

No more pages to load

Log In Register ×