Weekly Covid-19 Update: Tuesday, January 4, 2022
Happy Tuesday and Happy New Year, everyone. If you had told me back in May of 2020 when I first started writing these updates that I would still be doing them in 2022 I would’ve thought you were crazy. But here we are. Without further ado, your Covid research update for this week:
1) In case anyone out there is still not convinced of the effectiveness of masks in helping to prevent transmission of Covid-19, a new research study conducted in pre-schools and schools in Germany showed that Covid outbreaks were “effectively contained by an obligation for adults and children to wear face masks.” While the majority of outbreaks identified in the study started with a child as the index (original) case, when an adult (such as a teacher) was found to be the index case, there was a greater number of secondary infections (people infected by the index case). In schools with mandatory mask requirements for both adults and children, there was a significant decrease in the number of secondary cases. The researchers recommended that adults working in schools should be required to wear masks in order to help contain Covid outbreaks within the school. The study was peer-reviewed and published in Frontiers in Public Health. You can read the full article here: https://www.frontiersin.org/articles/10.3389/fpubh.2021.780039/full#h3
2) Researchers explored whether pregnant women who were vaccinated against Covid-19 were more likely to deliver their babies prematurely than those who were not vaccinated. The researchers studied over 46,000 pregnancies, 10,064 of which were in women who were vaccinated, and found no differences between premature births of babies born to vaccinated and unvaccinated women. The baby’s weight was also no different based on the mother’s vaccination status. The report noted that previous research showed a link between pregnant women infected with Covid and pre-term birth as well as evidence that vaccinated pregnant women were able to pass on antibodies to their infant, both points further justifying the need for pregnant women to be vaccinated. The study concluded, “evidence of the benefits of COVID-19 vaccination during pregnancy continues to accrue, including the detection of antibodies in cord blood. Together, these findings reinforce the importance of communicating the risks for COVID-19 during pregnancy, the benefits of vaccination, and information on the safety and effectiveness of COVID-19 vaccination during pregnancy.” The study was published in the CDC’s Morbidity and Mortality Weekly Report and can be read in full here: https://www.cdc.gov/mmwr/volumes/71/wr/mm7101e1.htm?s_cid=mm7101e1_w
3) A study examined the T-cell responses of individuals who were either vaccinated or had previously been infected by Covid to assess whether T-cells will provide protection against the Omicron variant. T-cells are white blood cells that originate in the bone marrow and help to determine our immune response to foreign substances in the body. The study concluded that T-cell responses elicited by vaccines or previous infection should offer protection against Omicron. The study noted, however, that T-cells will not necessarily prevent infection, but they should help to protect people against significant illness from Omicron. The study was peer-reviewed and published in the journal Viruses. You can read the full text here: https://www.mdpi.com/1999-4915/14/1/79/htm
4) A study which has not yet undergone peer review (important disclaimer) examined household transmissions of the Omicron variant compared to the Delta variant in nearly 12,000 households in Denmark. When the initial case was with the Omicron variant, 31% of households had at least one other household member test positive, compared to just 21% for the Delta variant. The study found that transmission rates for both variants were highest amongst those who were unvaccinated. Among the vaccinated, those who had a booster dose of the vaccine were less likely to catch the Omicron variant than those who only had two doses of the vaccine. They also found that Omicron was between 2.7–3.7 times more transmissible than Delta in vaccinated individuals. For unvaccinated people, though, there was no difference in transmissibility between the two variants, which led the researchers to conclude that Omicron’s transmissibility was due to its ability to evade immune responses rather than an inherent increase in its basic transmissibility. You can read the pre-print of the study here: https://www.medrxiv.org/content/10.1101/2021.12.27.21268278v1.full.pdf
5) A study that is currently under peer-review at the journal Nature Portfolio studied several different Covid-19 variants in mice and hamsters to better understand how different variants affected the body. Results showed that when infected with the Omicron variant, the animals experienced less lung damage, lost less weight, and were less likely to die than with previous variants. One specific type of hamster, the Syrian hamster, became severely ill when infected with previous variants of the virus but experienced much more mild symptoms with Omicron. These findings were consistent with initial research on humans infected with Omicron. You can read the pre-print of the study here: https://www.researchsquare.com/article/rs-1211792/v1
6) Preliminary findings from a clinical trial of the Johnson & Johnson vaccine as a booster dose against Omicron showed that it reduced the risk of hospitalization by 85%. The study involved 69,062 healthcare workers who were given the J&J booster (second dose of that vaccine) between 6–9 months after receiving their initial dose. The findings from the booster group were compared to those from a similar group of individuals who were not vaccinated. The researchers concluded that the findings were especially important for the continent of Africa, which has been very reliant on the J&J vaccine thus far in the pandemic. The study has not yet undergone peer review and the pre-print can be read here: https://www.medrxiv.org/content/10.1101/2021.12.28.21268436v1
7) Now for your world update. Yesterday the US had over 1 million new cases of Covid-19 for the first time ever in the pandemic. The total number of people testing positive was 1,017,376. Daily cases have increased 239% over the past two weeks and the average daily number of cases is nearly half a million. Hospitalizations have increased 41% in the same time period and deaths have decreased by 3%. The hardest-hit states/territories in terms of cases per capita at the moment include New York, New Jersey, Washington D.C., Puerto Rico, US Virgin Islands, Delaware, Massachusetts, Florida, Maryland, and Rhode Island.
— The UK also just hit a record for its number of daily cases with 218,724. Over the past two weeks the number of daily cases has increased 109%. Deaths have increased 14% over that time and hospitalizations are also on the rise, with several hospitals declaring critical incidents (meaning they are concerned they will not be able to provide priority services such as treatments for cancer patients or heart disease patients).
— Elsewhere, Italy and France both reported record numbers of new cases today with 170,844 and 271,686, respectively. Israel’s Prime Minister announced today that a study there showed a fourth dose of a Covid vaccine provided a five-fold boost in antibodies, although I have not yet been able to find the actual study (or a summary of it). Australia also recorded a record number of cases today at 47,799.
Sources:
US numbers: https://www.nytimes.com/interactive/2021/us/covid-cases.html
UK numbers: https://www.theguardian.com/world/coronavirus-outbreak
World news: https://www.theguardian.com/world/live/2022/jan/04/covid-live-news-chinese-city-puts-13-million-in-strict-lockdown-over-three-asymptomatic-cases
Australia numbers: https://www.reuters.com/world/asia-pacific/australias-covid-19-cases-surge-hospitalisations-hit-pandemic-high-nsw-2022-01-03/
That’s all for this week. I hope everyone’s 2022 is off to a good start. Thanks for reading and I’ll be back next week with another update.
