Pfizer vaccine effective in those with chronic illnesses

The following is a roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for Covid-19, the illness caused by the virus.

Third-trimester vaccination appears safe in early data

Among pregnant women who received Covid-19 vaccines manufactured by Pfizer and BioNTech SE or Moderna and who signed up for an online survey, side effects were no different than what has been seen in the general population, researchers reported Wednesday in The New England Journal of Medicine.

But they noted that data of this nature is still sparse. They looked at responses from smartphone users who participated in the US Centers for Disease Control and Prevention (CDC) "v-safe" program, which collects information on Covid-19 vaccination experiences.

Compared to non-pregnant women, the 35,691 pregnant responders reported more injection site pain but fewer headaches, muscle aches, chills, and fevers. Among 3,958 women who signed up for a CDC pregnancy registry, no one vaccinated in the first trimester has given birth yet.

The Vaccine Adverse Event Reporting System (VAERS), run jointly by the CDC and the US Food and Drug Administration, has recorded 46 miscarriages potentially related to Covid-19 vaccination, including 37 in the first trimester, the researchers said.

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"Early data from the v-safe surveillance system, the v-safe pregnancy registry, and the VAERS do not indicate any obvious safety signals with respect to pregnancy or neonatal outcomes associated with Covid-19 vaccination in the third trimester of pregnancy," researchers concluded.

Pfizer/BioNTech vaccine effective in people with chronic illnesses

The Pfizer/BioNTech Covid-19 vaccine is effective at preventing symptomatic and severe disease in people with some chronic illnesses, like diabetes and heart disease, according to a large real-world study published on Wednesday in The New England Journal of Medicine.

The analysis of almost 1.4 million people, conducted by Clalit, Israel's largest healthcare provider, showed the vaccine was 80% effective against symptomatic infection for people with heart or chronic kidney diseases, 86% for people with type 2 diabetes, 75% for cerebrovascular disease, and 84% for people suffering from immunodeficiency.

For vaccinated people with at least three chronic conditions or risk factors, the vaccine was 88% effective in preventing symptomatic infection. It was more than 90% effective against severe disease for people with type 2 diabetes, heart or cerebrovascular disease.

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The results were lower than the 95% overall vaccine effectiveness observed after the second dose in clinical trials last year. "These results are very encouraging, as they suggest that most Covid-19 cases will be prevented by vaccination even in the elderly and chronically ill," said Ran Balicer, Clalit's chief innovation officer.

Fever, shortness of breath are Covid-19 red flags in pregnancy

Pregnant women with Covid-19 and their newborns face "consistent and substantial increases" in risks of complications, an international study has found.

Covid-19 in newborns is associated with a three-fold risk of severe medical complications, according to the study by scientists at the University of Oxford. And pregnant women with symptomatic Covid-19 face higher risks of preterm delivery, preeclampsia (high blood pressure with organ failure risk), need for intensive care and death.

That was particularly true for women with fever and shortness of breath, according to a report published on Friday in JAMA Pediatrics.

"Women with Covid-19 during pregnancy were over 50% more likely to experience pregnancy complications compared to pregnant women unaffected by Covid-19," said co-author Aris Papageorghiou.

The study, conducted in 18 countries, included 706 pregnant women with Covid-19 and 1,424 similarly pregnant women without Covid-19 who were giving birth at the same hospital. Findings also showed a delivery by Caesarean section may be associated with an increased risk of virus infection in newborns. Breastfeeding, however, does not seem to heighten risks of transmission from mothers to babies, they found.