Study: Pfizer’s mRNA vaccine neutralizes COVID-19 variants
A study today in Nature Medicine showed Pfizer's mRNA vaccine, the first vaccine approved in the United States for use against COVID-19, neutralized three variants of the virus, including the B117 strain first identified in the United Kingdom, and two new variants first confirmed in South Africa.
The mutations tested included the N501Y from the United Kingdom and South Africa, the 69/70-deletion + N501Y + D614G from United Kingdom; and E484K + N501Y + D614G from South Africa.
To conduct the study, University of Texas Medical Branch researchers engineered three COVID-19 viruses with the spike mutations from the variants. They then measured neutralization geometric mean titers (GMTs) against the variants in 20 samples of human sera from subjects who had been vaccinated with Pfizer's two-dose vaccine 2 to 4 weeks earlier.
GMTs were 0.81- to 1.46-fold of the GMTs of the original, wild type virus, against which Pfizer’s vaccine is 95% effective.
As seen in other studies, the neutralization GMT of the serum panel against the virus with three mutations from the South Africa variant (E484K + N501Y + D614G) was slightly lower than the neutralization GMTs against the N501Y virus or the virus with mutations from the UK variants, the authors wrote. But the difference was not great.
"The magnitude of the differences in neutralization GMTs against any of the mutant viruses in this study was small (0.81- to 1.41-fold), as compared to the greater than four-fold differences in hemagglutination-inhibition titers that have been used to signal potential need for a strain change in influenza vaccine," the authors concluded.
They suggested ongoing surveillance of variants.
Feb 8 Nat Med study
Novel antiviral interferon lambda may offer COVID-19 outpatient benefits
After adjusting for baseline viral load, COVID outpatients are more than four times more likely to have an undetectable viral load when treated with the experimental drug interferon lambda, according to a small study published late last week in The Lancet Respiratory Medicine.
Interferon lambda is an antiviral protein that uses multiple pathways to attack viruses. It is most active in the liver, lungs, and intestine.
The researchers treated 29 people with one 180-microgram injection of interferon lambda and 30 with a placebo from May 18 to Nov 4, 2020, in Toronto. At day 7, 82.8% of the intervention group had undetectable viral loads compared with 63.3% of the placebo group, resulting in an adjusted odds ratio of 4.12 (95% confidence interval [CI], 1.15 to 16.73). The results were more marked for those with a higher viral load of at least 106: The intervention group was 8.16 times more likely to test negative (95% CI, 1.76 to 51.5).
Interferon lambda's effects were able to be seen starting on day 3 after injection, according to the researchers. Viral load decline was 0.81 log copies per milliliter greater in the treatment group vs the placebo group, which increased to a difference of 1.67 log copies by day 5 and 2.42 log copies by day 7.
"If we can decrease the virus level quickly, people are less likely to spread the infection to others and we may even be able to shorten the time required for self-isolation," says Jordan Feld, MD, MPH, lead author, in a University Health Network press release.
Pandemic-related food security, lower income noted in poorer nations
International phone surveys across nine lower- and middle-income countries (LMICs) found that, during the COVID-19 pandemic, residents have experienced a median 70% income loss and 30% unemployment rate as well as food insecurity (a median 45% have skipped or reduced meals), difficulty accessing markets (31%), and limited healthcare (13%). The results were published in Science Advances late last week.
The researchers surveyed 16 subpopulations using pre-determined pools and randomized dialing in Burkina Faso, Ghana, Kenya, Rwanda, Sierra Leone, Bangladesh, Nepal, the Philippines, and Colombia, reaching more than 30,000 households. Kenya and Bangladesh made up more than 50% of the study cohort.
While the surveys took place from April through early June 2020, the researchers say that already in April, approximately 50% of those surveyed had begun rationing or skipping meals.
"Even in Colombia," the researchers write, "the country in our sample with the highest per capita GDP and thus potentially the greatest financial resources to cope with the crisis, the majority of respondents report drops in income (87%) and employment (49%), and an increase in food insecurity (59%)."
The researchers say looking at individual ranges is just as important as median figures to understand the pandemic's full impact. For instance, only 8% of Kenyan refugee households experienced income loss, but 69% of the country's rural households did. Median national or humanitarian aid was 11%, but subgroups ranged from no coverage to 49%. And despite reporting the highest rates of assistance (26%), 27% of Bangladesh's Rohingya refugees reported food insecurity.
"We find that the economic shock in these countries—where most people depend on casual labor to earn enough to feed their families—leads to deprivations that seem likely to generate excess future morbidity, mortality, and other adverse longer-term consequences," the researchers write, adding that children are particularly vulnerable to food insecurity, school closures, and inadequate healthcare.
In their discussion and in press releases, the researchers advocate for worldwide COVID vaccines, aid policies that don't spur additional COVID transmission risks, and "graduation programs" that can increase training and provide income during such times.
Feb 5 Sci Adv study
Feb 5 University of California Berkeley press release
Feb 5 Innovations for Poverty Action press release