A study by the University of Oxford carried out in 41 hospitals in 18 countries revealed that vaccines reduce complications in pregnancy against the Omicron variant and it is unvaccinated pregnant people who have the highest risks.
The Intercovid 2022 study , published by the University of Oxford, in the scientific journal The Lancet , evaluated the impact of the Covid-19 Ómicron variant on maternal and neonatal outcomes.
The work was carried out in 41 hospitals in 18 countries on 1,545 pregnant women diagnosed with Covid-19 and 3,073 pregnant women not diagnosed with the virus.
The results showed that pregnant people, vaccinated and preferably with the additional booster dose, were "adequately protected" against the symptoms and serious complications of Covid-19 Omicron, and had "a very low risk" of admission to care units. intensive.
The Omicron variant during pregnancy was associated with an increased risk of maternal morbidity, serious pregnancy complications, and hospital and intensive care unit admissions, especially among symptomatic and unvaccinated women , and in particular, the risk of preeclampsia (high blood pressure). and signs of liver or kidney damage that can occur in women after the 20th week of pregnancy) increased among women with severe symptoms. Overweight or obese women with severe symptoms had the highest risk of maternal morbidity and serious complications.
The global hospital network coordinated by the Oxford Maternal and Perinatal Health Institute (OMPHI) conducted the study between November 27, 2021 and June 30, 2022 , a period during which Ómicron was the predominant variant and the effectiveness of the vaccine against this variant.
The report maintains that mRNA vaccines were the most effective in preventing symptoms and serious complications of Covid-19 Omicron, although viral vector vaccines with a booster dose also provided adequate protection , for at least 10 months after the last dose.
For his part, Professor of Perinatal Medicine at the University of Oxford, José Villar , co-director of the Intercovid 2022 study, stated that they have "provided solid, evidence-based information on the increased risk of Covid-19 Omicron during pregnancy of suffering severe maternal complications, especially among symptomatic women and those who were not vaccinated.
"Our study clearly indicates the need for a complete vaccination schedule during pregnancy, and with a booster dose, to provide protection for at least 10 months after the last dose. Antenatal services around the world should strive to include vaccination against Covid-19 in the routine care of pregnant women," said the doctor in statements cited by the Télam agency.
Professor of Fetal Medicine at the University of Oxford, Aris Papageorghiou, co-leader of the research, said that "although the Omicron variant may be less harmful than previous variants in the general population, unvaccinated pregnant women around the world continue to be infected. having a high risk of complications.
"Since it is impossible to predict who will develop serious symptoms or complications, complete and universal vaccination during pregnancy is required," he said.
Abstract translated from the original work: Pregnancy outcomes and vaccine effectiveness during the period of omicron as the variant of concern, INTERCOVID-2022: a multinational, observational study. Pregnancy and vaccine effectiveness during the period of omicron as the variant of concern. INTERCOVID-2022: a multinational observational study. An increased risk associated with COVID-19 in pregnancy was observed in 2021. Since then, the SARS-CoV-2 virus has undergone genetic mutations. The objective was to examine the maternal and perinatal effects of COVID-19 during pregnancy and evaluate the effectiveness of vaccination, when omicron (B.1.1.529) was the variant of interest. INTERCOVID-2022 is a large prospective observational study involving 41 hospitals in 18 countries. Each woman with real-time PCR or rapid testing, laboratory-confirmed COVID-19 in pregnancy was compared with two unmatched women without a diagnosis of COVID-19 who were recruited concomitantly and consecutively in pregnancy or at delivery. The mother and neonate dyads were followed until hospital discharge. The primary outcomes were maternal morbidity and mortality index ( MMMI ), severe neonatal morbidity index ( SNMI ), and severe perinatal morbidity and mortality index ( SPMMI ). The effectiveness of the vaccine was estimated, adjusted for maternal risk profile. 4,618 pregnant women were enrolled from November 27, 2021 (the day after WHO declared Omicron as a variant of concern) to June 30, 2022: 1,545 (33%) women had a diagnosis of COVID-19 ( median gestation 36.7 weeks [IQR 29·0–38·9]) and 3073 (67%) women, with similar demographic characteristics, did not have a diagnosis of COVID-19. Overall, women with a diagnosis had a higher risk of MMMI (relative risk [RR] 1·16 [95% CI 1·03–1·31]) and SPMMI (RR 1·21 [95% CI 1·00 –1 ·46]). Women with a diagnosis, compared with those without a diagnosis, also had an increased risk of SNMI (RR 1·23 [95% CI 0·88–1·71]), although the lower limits of the 95% CI crossed unity . Unvaccinated women diagnosed with COVID-19 had a higher risk of MMMI (RR 1·36 [95% CI 1·12–1·65]). Severe COVID-19 symptoms in the total sample increased the risk of severe maternal complications (RR 2.51 [95% CI 1.84–3.43]), perinatal complications (RR 1.84 [95% CI 1.84–3.43]), 02– 3·34]), and referral, intensive care unit (ICU) admission, or death (RR 11·83 [95% CI 6·67–20·97]). Severe COVID-19 symptoms in unvaccinated women increased the risk of MMMI (RR 2·88 [95% CI 2·02–4·12]) and remission, ICU admission, or death (RR 20·82 [95% CI 2·02–4·12]). % 10·44–41·54]). 2,886 (63%) of 4,618 total participants received at least a single dose of either vaccine, and 2,476 (54%) of 4,618 received full or booster doses. Vaccine effectiveness (all vaccines combined) for severe COVID-19 complications for all women with a full regimen was 48% (95% CI: 22–65) and 76% (47–89) after a booster dose. For women diagnosed with COVID-19, the vaccination efficacy of all vaccines combined for women with a full regimen was 74% (95% CI: 48–87) and 91% (65–98) after a booster dose. In the present trial, as in the general population, it was confirmed that vaccination during pregnancy did not prevent infection with the omicron variant. This finding is due to the fact that SARS-CoV-2 has developed a considerable capacity to escape antibodies, demonstrated by its high possibility of infecting or reinfecting people with a certain degree of immunity. In summary, the findings suggest that COVID-19 in pregnancy, during the first 6 months of Omicron as the variant of concern, was associated with an increased risk of severe maternal morbidity and mortality, especially among symptomatic and unvaccinated women . Women with a complete vaccination schedule had a reduced risk of severe symptoms, complications and death. Vaccination coverage among pregnant women remains a priority. |
Figure 1: Vaccine efficacy against serious maternal complications or death by time after vaccination, according to partial, complete or booster doses during the time of omicron (B.1.1.529) as a variant of interest (all types of combination vaccines) Serious maternal complications include severe COVID-19 symptoms, referral to a higher level of care, admission to hospital during pregnancy for respiratory illness, respiratory tract infection requiring treatment with antibiotics or antivirals, or admission to the intensive care unit.
Figure 2: Vaccine efficacy against serious maternal complications or death by time post-vaccination, by vaccine type during time of omicron (B.1.1.529) as variant of concern (all doses combined) Maternal complications Severe symptoms include severe COVID-19 symptoms or referral to a higher level of care or admission to hospital during pregnancy for respiratory illness or respiratory tract infection requiring treatment with antibiotics or antivirals or admission to the intensive care unit.
