Getting vaccinated against COVID-19 while pregnant passes along protection against infection and hospitalization to newborns, a Canadian study says.
The research, published within the BMJ (British Medical Journal) on Wednesday evening, found that protection against COVID-19 for infants was handiest when moms got their second or third dose of mRNA vaccine while pregnant.
A booster shot while pregnant bolstered protection against the Omicron variant particularly, said the study authors from the Canadian Immunization Research Network.
Canadian infectious diseases specialists, obstetrician-gynecologists and immunologists have long urged pregnant people to not sleep so far on their COVID-19 vaccinations — including boosters — because they’re at higher risk of significant illness in the event that they develop into infected. That in turn can harm the fetus, they are saying.
This study shows that getting vaccinated while pregnant can be “of great profit to the infant” after they’re born, said Dr. Deborah Money, a professor of obstetrics and gynecology who focuses on infectious diseases on the University of British Columbia.
Money, who was not involved within the study, said the Canadian findings are consistent with existing international research.
The researchers found that maternal vaccination protected the newborn against COVID-19 infection for the primary eight weeks after they were born.
Dawn Bowdish, an immunology professor at Hamilton’s McMaster University who was not involved within the study, noted those are essential weeks with “major developmental stuff occurring.”
“Considered one of Mom’s best gifts for that baby (has) at all times been her antibodies,” said Bowdish, noting that booster shots for pertussis (whooping cough) and influenza are routinely advisable for pregnant women in order that their babies are born with some immunity to those diseases.
There may be currently no COVID-19 vaccine available for babies until they reach six months of age.
The researchers checked out data for 8,809 infants born in Ontario who received COVID-19 PCR tests between May 31, 2021, and Sept. 5, 2022, — a time period when the Delta variant was widely circulating at first, followed by the Omicron variant later.
They linked that information to the variety of mRNA COVID-19 vaccinations the moms had while pregnant — one, two or three doses — in addition to unvaccinated moms.
The information got here from the independent non-profit health data organization ICES.
The researchers found that a second vaccine dose while pregnant provided strong protection against the Delta variant for the newborn. The study showed 95 per cent effectiveness against Delta infection and 97 per cent effectiveness against hospital admission as a result of Delta infection.
For the Omicron variant, the mother’s second dose provided newborns with moderate protection: 45 per cent protection against Omicron infection and 53 per cent protection against hospitalization as a result of the Omicron variant.
But protection for newborns against Omicron increased substantially when moms had a 3rd dose of vaccine while pregnant, with 73 per cent effectiveness against infection and 80 per cent effectiveness against hospital admission.
In keeping with ICES, fewer than half of pregnant women in Ontario have had three doses of COVID-19 vaccine.
A spokeswoman for the Public Health Agency of Canada said it doesn’t have information on COVID-19 vaccine coverage amongst pregnant women but that it plans to gather it in the long run.
Lead creator Sarah Jorgensen said that a variety of women are unsure if it’s value getting a booster while they’re pregnant.
“I believe our study gives them more certainty across the profit to the infant,” said Jorgensen, who’s a pharmacist studying perinatal epidemiology.
The researchers also found that getting a COVID-19 vaccine dose throughout the last trimester of pregnancy could increase protection for the newborn.
But each Money and Bowdish emphasized that a very powerful factor is how long it’s been for the reason that mother’s last dose as a result of waning immunity.
“All the info, including research from my very own group, shows that to essentially protect you from symptomatic (COVID-19) infections, you may’t be greater than six months out once you encounter this virus,” said Bowdish.
If it’s been greater than six months since your last dose, “we’re suggesting (you) just get vaccinated no matter where you might be in your pregnancy,” Money said.
In some cases, two doses of vaccine might be warranted over the course of a nine-month pregnancy, she said.
“If you happen to, say, got vaccinated very early in pregnancy, you might boost later because you may boost inside as short as three months,” Money said.
The study authors noted that their research has limitations.
One is that moms also pass along antibodies to their infants through breastfeeding, so it’s possible that played a task that couldn’t be measured. One other is that they only had data on babies who were tested for COVID-19 with lab-confirmed PCR tests, in order that they couldn’t include any home rapid antigen test results.
This report by The Canadian Press was first published Feb. 8, 2023.
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