Weekly Coronavirus Update: Tuesday, May 4, 2021

Happy Tuesday, everyone. This week’s update on Coronavirus-related research and news contains a lot of information on vaccines (effectiveness, side effects, transmissibility after vaccination), Covid-19 and menstrual cycles, the prevalence of outbreaks in counties with meatpacking facilities, incentivizing Americans to get vaccinated, and of course your world update.

1) Real-world data on vaccines in people over the age of 65 in the US showed that those who were fully vaccinated had a 94% reduction in the risk of being hospitalized with Covid, while that number was 64% for people who had received only their first dose of the vaccine. The Centers for Disease Control and Prevention collected data from 24 hospitals in 14 different states between January 1 — March 26, 2021. The authors of the study, published in the CDC’s Morbidity and Mortality Weekly Report, concluded, “These data suggest that continuing to rapidly vaccinate U.S. adults against COVID-19 will likely have a marked impact on COVID-19 hospitalization and might lead to commensurate reductions in post-COVID conditions and deaths.” You can read the full study here: https://www.cdc.gov/mmwr/volumes/70/wr/mm7018e1.htm?s_cid=mm7018e1_w

2) The UK-based Covid Symptom Study published data on side-effects from the AstraZeneca and Pfizer vaccines experienced by 627,383 individuals. Systemic side effects (e.g., headache, fatigue, fever, nausea, chills) were experienced by 13.5% of people after their first dose of Pfizer and 33.7% of people who received a first dose of AstraZeneca. The study only collected data on the second dose from those with the Pfizer vaccine, and 22.0% of people experienced systemic side effects after that. Local side effects (e.g., sore arm) were reported by 71.9% after the first Pfizer dose, 68.5% after the second Pfizer dose, and 58.7% after the first AZ dose. The study also found that systemic side effects were more common for recipients of both vaccines in people who previously had Covid-19 (1.4 and 1.2 times higher in the AZ and Pfizer recipients, respectively). Women and younger individuals also reported more adverse effects from the vaccine, though the authors noted that the effects were short-term and mild in severity. Both vaccines were also found to be effective in significantly reducing the risk of infection. The study was peer-reviewed and published in the journal The Lancet Infectious Diseases: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(21)00224-3/fulltext?mc_cid=031ea01430&mc_eid=fe4252eca9

3) Another study conducted in the UK looked at people who received one vaccine dose (either AstraZeneca or Pfizer) but tested positive for Covid-19 after the dose. Data showed that 21 days after vaccination, the risk of these individuals transmitting the virus to other members of their household was 40–50% lower than transmission in households where the first infected individual had not been vaccinated. This is one of the first known studies to show that the vaccines can help to prevent transmission in vaccinated but infected individuals. The findings also underscore the importance of vaccinating as many people as possible. The study has not yet undergone peer review (important disclaimer), but you can read the pre-print of it here: https://khub.net/documents/135939561/390853656/Impact+of+vaccination+on+household+transmission+of+SARS-COV-2+in+England.pdf/35bf4bb1-6ade-d3eb-a39e-9c9b25a8122a?t=1619551571214

4) Two separate studies found that Covid-19 vaccines are less effective in organ transplant recipients than the general public. The first study, published in JAMA, examined 436 transplant recipients who had been vaccinated with either the Pfizer or Moderna vaccine. After one vaccine dose, only 17% of the participants had detectable antibodies. After the second dose this number jumped up to 37% in people who received immunosuppression therapy and 63% in those who were not on any immunosuppression regimen. Additionally, older transplant recipients were less likely to develop an antibody response. The authors concluded that transplant recipients may remain at higher risk of contracting Covid-19 even when vaccinated. The second study, which has not yet undergone peer review (important disclaimer!), studied kidney transplant patients and people on dialysis. None of the 40 participants who had received kidney transplants developed antibodies after vaccination. Conversely, of the 44 dialysis patients involved in the study, 70.5% developed IgG antibodies and 68.2% developed IgA antibodies. Based on the findings the researchers stated, “There is an urgent need to improve vaccination protocols in patients after kidney transplantation or on chronic dialysis.” You can read the two studies below:
Study one: https://jamanetwork.com/journals/jama/fullarticle/2777685
Study two: https://www.medrxiv.org/content/10.1101/2021.04.15.21255550v1.full.pdf

5) Does Covid-19 have an effect on women’s menstruation or sex hormones? Researchers examined data from 237 women of child-bearing age who were hospitalized with Covid-19 between January to April 2021. Findings showed that 25% of the women experienced changes in their menstrual volume (20% had a decrease in volume and only 5% had an increase), 28% experienced changes to their menstrual cycle (18% had a prolonged cycle, 3% had a shortened cycle, and 7% had cycle disorders), and there were no differences in the sex hormone concentrations between women who had Covid and those who did not. The researchers noted that “follow-up showed that 84% returned to a normal menstrual volume, and 99% of patients returned to their normal cycle within 1–2 months after discharge, suggesting that changes in menstruation caused by COVID-19 were most likely temporary changes and resolved in a short period.” Additionally, they concluded that their study offered no evidence that Covid-19 substantially impairs fertility in women. The study was peer-reviewed and published in the journal Reproductive BioMedicine Online: https://www.sciencedirect.com/science/article/pii/S1472648320305253
*Relatedly, researchers from the University of Illinois are studying whether Covid-19 vaccines impact women’s menstruation. If you would like to take part in the study, you can complete their survey here: https://redcap.healthinstitute.illinois.edu/surveys/index.php?s=LL8TKKC8DP&fbclid=IwAR2j6ksMtPy6xzuuNZy37yoXaatI4Q6Ull3um6X3gDpHfBZZCe8JvEYfHeU

6) Early in the pandemic you probably heard about Covid-19 outbreaks in meatpacking plants. A recent study published in the peer-reviewed journal Food Policy examined the impact of large meatpacking plants on county-level Covid-19 transmission data in the United States. Within 150 days of the emergence of Covid-19 in a given county, per capita infection rates increased 160% in counties with large pork processing facilities, 110% in those with large beef packing facilities, and 20% in those with chicken processing facilities; all of these were relative to comparable counties without meatpacking facilities. These facilities tend to involve a large number of people working in extremely close proximity to each other, and the intense work involved leads to heavy breathing, thus a greater chance of spreading the virus. The authors stated that their results “suggest that 334 thousand COVID-19 infections are attributable to meatpacking plants in the U.S. with associated mortality and morbidity costs totaling more than $11.2 billion.” You can read the full study here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8026277/

7) The rate of vaccinations in the U.S. is slowing down despite the fact that only 44% of the population has had at least one dose. Researchers from the UCLA Covid-19 Health and Politics Project attempted to understand how to persuade the millions of Americans who have yet to get a vaccine to do so. A nationwide survey of nearly 15,000 people revealed the following incentives for vaccination: 1) a payment of $100 (34% said this would make them more likely to get a vaccine), and 2) being able to not wear a mask after being vaccinated (63%). The study found that Democrats were incentivized by the cash payment more than Republicans, whereas Republicans were more likely to be motivated by not having to wear a mask. Another aspect of the study was to understand the social activities of vaccinated and unvaccinated individuals. Those who were not vaccinated reported higher rates of dining at a restaurant in the last two weeks (53% unvaccinated; 15% one vaccine dose; 32% fully vaccinated), gathering with more than 10 non-family members outdoors (52% unvaccinated, 21% one dose, 27% fully vaccinated), and gathering with more than 10 non-family members indoors (46% unvaccinated, 14% one dose, 40% fully vaccinated). The results of this research were widely reported in media outlets today, although I have not been able to find the actual study itself (it was not linked in any of the news articles I saw). You can read a full article about the findings in the New York Times. The article was written by one of the study’s researchers: https://www.nytimes.com/2021/05/04/upshot/vaccine-incentive-experiment.html

8) Now for your world update. First, in the US the rates of new cases, hospitalizations, and deaths continue to decline. Over the past two weeks there has been a 26% decrease in daily new infections and the average number of daily cases over the past seven days is 49,641. Hospitalizations have decreased 10% and deaths have decrease 3%. In terms of vaccines, 32% of the population is fully vaccinated and 44% have received one dose. Yesterday it was widely reported that medical experts do not believe the US will reach herd immunity due to vaccine hesitancy, inequitable vaccine distribution, and the prevalence of more contagious variants. The experts said instead, the goal will likely be to transition Covid-19 into a cold-like virus over the next few generations.
— In the UK numbers continue to drop as well. Over the last two weeks the number of daily new cases has decreased by 15% and deaths have decreased 40%. The seven-day average number of new daily infections is 1,649. In terms of vaccines, 51.8% of the population has received at least one dose and 23.2% are fully vaccinated.
— Elsewhere, India surpassed a total of 20 million Covid-19 cases with 357,229 new cases yesterday. Their seven-day average is 378,092 new daily cases. The nation recorded 3,449 new deaths yesterday as well. The Indian Premier League (IPL) cricket has been suspended due to concerns over the rapid spread of the virus. Germany announced plans to allow more freedoms for people who have been fully vaccinated, but the plan is being criticized for discriminating against young people who won’t be able to receive their first dose for a few months. Japan hit an all-time high for its number of Covid-19 patients with severe symptoms yesterday at 1,084. Highly contagious variants of the virus are also driving up the number of new infections in the western part of the country.
US numbers: https://www.nytimes.com/interactive/2021/us/covid-cases.html
US not likely to reach herd immunity: https://www.independent.co.uk/news/world/americas/herd-immunity-covid-vaccine-biden-b1841322.html
UK numbers: https://www.theguardian.com/world/2021/apr/21/covid-uk-coronavirus-cases-deaths-and-vaccinations-today
India: https://news.sky.com/story/covid-19-india-coronavirus-cases-soar-past-20-million-with-health-system-on-brink-of-collapse-12294499
Germany: https://www.theguardian.com/world/live/2021/may/04/coronavirus-live-news-india-passes-20m-cases-us-average-daily-infections-fall-below-50000
Japan: https://www.japantimes.co.jp/news/2021/05/03/national/coronavirus-japan-may3/

That’s all for this week. Please keep safe and get your vaccine when you are eligible!



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