Day: December 15, 2021

Categories : COVIDTags :

Real-world Data Shows Booster Shot Protective against Omicron

On By ModernMedia
Photo by Mat Napo on Unsplash

While two doses of a COVID vaccine offered less protection against Omicron, a booster shot restored immunity back to high levels, according to real-world data from the UK.

Two doses of Pfizer vaccine provided just under 40% protection against symptomatic infection with the Omicron variant about 25 weeks after the second dose compared with around 60% protection against Delta, according to a technical briefing released by the UK Health Security Agency. [PDF]

“These early estimates suggest that vaccine effectiveness against symptomatic disease with the Omicron variant is significantly lower than compared to the Delta variant,” the agency noted in the report. However, “moderate to high” vaccine effectiveness was observed in the early period after a booster shot, they added.

The agency found that a Pfizer booster increased vaccine effectiveness to 76%. Among people who received the AstraZeneca series for their initial immunisation (which offered almost no protection against Omicron), vaccine effectiveness jumped to 71% after a Pfizer booster.

The reportcompared vaccine effectiveness against Omicron versus Delta, including 581 people who were infected with the new strain and more than 56 000 infected with Delta from the end of November to December 6.

Omicron’s reinfection rate was also much higher than Delta’s. Of 329 individuals infected with Omicron, 7% had a previous infection, compared with 0.4% of the approximately 85 000 people infected with Delta.

After adjustments for age and area, the risk ratio of reinfection for Omicron was 5.2 (95% CI 3.4-7.6).

The report also found a 20- to 40-fold reduction in neutralising antibody activity compared with the viruses used to develop the vaccines. However, a booster dose significantly improved neutralising antibodies, regardless of which vaccine was given in the initial immunisation.

Katelyn Jetelina, PhD, an epidemiologist at the University of Texas Health Science Center at Houston, said that the study data confirm what researchers have already discovered in lab research: vaccines offer significantly less protection against Omicron, and reinfection rates are expected to be high.

Dr Jetelina noted that it was reassuring to see that “we can curb infection still with a booster, which is really quite phenomenal.” However, she said that cases were likely to increase.

“I think all this data is showing us that we’re going to have a lot of infections with Omicron,” Jetelina told MedPage Today. While a high rate of infection does not necessarily translate to severe illness, Dr Jetelina said that she is concerned about population-level outcomes resulting from a flood of new cases.

“That’s where I get a bit more nervous,” she said. She pointed out that “even if the rate of severe disease is low […] those numbers start adding up real quickly.”

The UK Health Security Agency advised interpreting the results with caution, due to the low number of Omicron cases. Additionally, more data are needed before scientists can determine how well vaccines will work against severe illness, hospitalisation, and death from the Omicron strain.

“It will be a few weeks before effectiveness against severe disease with Omicron can be estimated,” the agency stated. “However, based on this experience, this is likely to be substantially higher than the estimates against symptomatic disease.”

Source: MedPage Today

Categories : Cancer Obstetrics & GynaecologyTags :

Synthetic Progestogen in Utero Leads to Doubled Cancer Rate in Offspring

On By ModernMedia
Photo by Shvets Productions on Pexels

In utero exposure to a synthetic progestogen used to prevent miscarriage can lead to an increased risk of developing cancer, according to a new study.

The study by researchers at The University of Texas Health Science Center at Houston (UTHealth Houston) was published in the American Journal of Obstetrics and Gynecology.

The drug, 17α-hydroxyprogesterone caproate (17-OHPC), is a synthetic progestogen frequently used by women in the 1950s and 1960s, and is still prescribed today to women to help prevent preterm birth. Progesterone helps the uterus grow during pregnancy and prevents early contractions that may lead to miscarriage.

“Children who were born to women who received the drug during pregnancy have double the rate of cancer across their lifetime compared to children born to women who did not take this drug,” said the study’s lead author, Caitlin C. Murphy, PhD, MPH, associate professor in the Department of Health Promotion and Behavioral Sciences at UTHealth School of Public Health in Houston. “We have seen cancers like colorectal cancer, pancreatic cancer, thyroid cancer, and many others increasing in people born in and after the 1960s, and no one really knows why.”

Researchers reviewed data from the Kaiser Foundation Health Plan on women who received prenatal care between June 1959 and June 1967, and the California Cancer Registry, which traced cancer in offspring through 2019.

Out of more than 18 751 live births, researchers discovered 1008 cancer diagnoses were made in offspring ages 0 to 58 years. Additionally, a total of 234 offspring were exposed to 17-OHPC during pregnancy. Offspring exposed in utero had cancer detected in adulthood at more than twice the rate of of those unexposed: 65% of cancers occurred in adults younger than 50.

“Our findings suggest taking this drug during pregnancy can disrupt early development, which may increase risk of cancer decades later,” Murphy said “With this drug, we are seeing the effects of a synthetic hormone. Things that happened to us in the womb, or exposures in utero, are important risk factors for developing cancer many decades after we’re born.”

A new randomised trial shows there is no benefit of taking 17-OHPC, and that it does not reduce the risk of preterm birth, according to Murphy.

The U.S. Food and Drug Administration proposed in October 2020 that this particular drug be withdrawn from the market.

Source: University of Texas Health Science Center at Houston